Chapter 1

A Biosocial Overview of Adult Human Sexual Behavior with Children and Adolescents

Jay R. Feierman *

* Department of Psychiatry, University of New Mexico, and
* Department of Behavioral Medicine Presbyterian Healthcare Services
Albuquerque, New Mexico

Chapter 1 of: Jay R. Feierman, Editor, Pedophilia, Biosocial Dimensions, Springer 1990


Sex, Culture, and the Biosocial Perspective

The word "sex" usually captures people’s attention when it occurs in book titles, magazine articles, and newspaper headlines, especially when the word is referring to sexual behavior that falls outside a socially acceptable boundary.

Interestingly, such boundaries appear to be somewhat arbitrary, inasmuch as a given society can ignore or rigidly enforce the transgressions of its members over very short periods of historical time (see Bullough, this volume). In addition, neighboring societies can and often do have very different boundaries that pertain to the "with whom" and "what context" aspects of sexual behavior.

Until now, science has had less an understanding of the biosocial factors that determine and regulate adult human sexual behavior with children and adolescents than it has had an understanding of the culturally transmitted boundary markers, such as age-of-consent laws and incest taboos.

This volume is more concerned with sexual behavior per se and its biosocial determination and regulation than with the culturally transmitted, humans-created, age-of-consent laws and incest taboos. There already is a large body of literature on the age-of-consent laws as well as on the cultural variations and correlations of the incest taboos.

Sexual reproduction between a parent and that individual’s adolescent or adult offspring is extremely rare in any species under natural conditions, and nonhuman species do not have culturally transmitted age-of-consent laws or incest taboos, which commonly are believed to prevent such behavior in humans (see Pusey, this volume). Yet, to some degree, the very same "wild" animals under certain conditions of captivity — as well as domesticated animals in barnyards, backyards, and pastures — often will mate with their own adolescent or adult offspring. Sexual behavior, as this example shows, therefore, is context dependent.

This context dependency also may have relevance in the understanding of adult human sexual behavior with children and adolescents, whether the child or adolescent is related to the adult who is involved in the behavior or not, inasmuch as many humans do not live under socio-ecological conditions that even resemble natural conditions, i.e., the context in which their genotypes evolved.

In the nonhuman primates that have been and are being adequately studied under natural and semi-natural conditions, even though parent/offspring mating is observed infrequently at any age of the offspring, other copulatory, as well as non-copulatory, forms of sexual behavior between related and non-related adults and juveniles are common and predictable and appear to have adaptive functions, depending on the particular species

(see Anderson and Bielert, this volume; de Waal, this volume; Pusey, this volume).

That this behavior is predictable, functional, and seemingly adaptive in some nonhuman primates suggests that there are biosocial factors that predate human culture (i.e., age-of-consent laws and incest taboos), factors that both determine and regulate species-typical, adult/juvenile sexual behavior.

This volume seeks to elucidate these same types of biosocial determining and regulating factors in the human species.

The biosocial perspective around which this volume is organized has provided useful insights into other socially unacceptable behavior, such as infanticide, homicide, child abuse, rape, incest, and adultery.

The biosocial perspective asks several questions:

Is or was a given behavior or category of behavior maladaptive or adaptive?
If it is or was adaptive, how is this determined, and how did it evolve?
What factors influence its regulation and dysregulation?

"Adaptive," as it is used in the biological sense, simply means "the facilitating of getting one’s genes into the next generation."

Adaptive behavior can be legal or illegal, moral or immoral, socially acceptable or socially unacceptable. 

Sexual Behavior

This volume is mainly about sexual behavior. "Sexual behavior" can be defined in several ways, such as

(a) "any behavior performed during measurable or observable sexual arousal,"
(b) "any behavior that uses copulatory motor patterns,"
(c) "any behavior that involves touching (one’s
own or others’) genitals," and
(d) "any behavior that signals, by species-specific movements, an internal readiness, or mood, to mate."

There is a contrasting point of view that espouses that all humans are sexual
beings and, therefore, that all behavior that an individual engages in is sexual. This definition of "sexual behavior" is so broad that it loses all usefulness.

Most reported adult human sexual behavior with children and adolescents concerns sexual behavior involving adult males rather than adult females, by a ratio of approximately 10:1

(Abel et al., 1987; Gebhard et al., 1965; Linder and Seliger, 1947).

This volume does not address the involvement of adult females because too little information currently is known and has been written about the topic.

Although differences in the processes through which males and females are socialized have been proposed as explanations of this behavioral sex difference

(Finkelhor, 1984; Maccoby and Jacklin, 1974),

there are also many complementary biosocial explanations

(see Eibl-Eibesfeldt, this volume; Gladue, this volume; Hutchison and Hutchison, this volume; Mackey, this volume; Medicus and Hopf, this volume; Taub, this volume).

Since behavioral sex differences are seen in both social and nonsocial nonhuman primates (Mitchell, 1979) as well as in almost all other well-studied nonprimate species (Wickler, 1973), the explanatory adequacy of "differential socialization“ alone, devoid of biology, is questionable.

In order to understand adult human sexual behavior with children and adolescents, this author finds it useful to divide sexual behavior into the three traditional phases,

receptive, and

but to define these phases in terms of their functions (i.e., their effects) in a biosocial-communications context rather than in terms of their structure, which is more traditional:

1. Proceptive behavior functions in eliciting sexual behavior by an
uncommitted individual.
2. Receptive behavior functions in the mutual acknowledgement of
ongoing or impending sexual behavior.
3. Conceptive behavior is the performing of species-typical, sexual,
behavioral motor patterns that are used in consummating an
adult-male/adult-female sexual relationship.

Many human societies have names as well as ritualized rights of passage for the formal transition through the three phases — e.g., maidenhood, engagement, and marriage — with ornamental acknowledgement of each phase in the form of hair style, clothing, and jewelry. However, in contrast to the months to years that elapse as one moves through the phases in the context of formal engagement and marriage, the transition from the proceptive to the conceptive phase can take minutes to hours when the relative permanency of a relationship or the creation of heirs are not issues.

Sexual Motivation and Mood

"Motivation" means "the total of all factors, both internal and external
to the individual, that increase the probability of a particular behavior’s
"Mood" is a subset of motivation; it encompasses some of the
internal factors only and is synonymous with the ethological concept "a
specific, internal readiness to act" (see Eibl-Eibesfeldt, 1975).

In this volume, in which new empirical data are introduced and old empirical data are reviewed, the material that is presented is organized around a biosocial, theoretical framework that will help interested persons better understand not only the behavior involved but also, at least to some modest degree, motivational factors and moods.

Readers of this volume with legal interests may want to understand both internal and external "motives." Clinicians may want to know more about internal moods, which are self-perceived as "feelings," and external "risk factors." These areas, which often overlap, are addressed in this volume, at least to the extent that they relate to or are predictive of behavior.

Sexual Interactants

To understand adult human sexual behavior with children and adolescents, one must address sexual awareness, attention, arousal, and behavior in the interactants. The term "interactants" may disturb some readers, inasmuch as there has been a trend in the clinical literature on child sexual abuse to conceptualize adult-child and adult-adolescent sexual behavior within a victimological paradigm (see Okami, this volume).

In that paradigm, the child or adolescent is seen as the passive "victim" of the
"perpetrator’s" "sexual aggression"

(e.g., Burgess et al., 1978; Finkelhor, 1984).

This terminology is not used in this volume. Rather, purely descriptive terms are used.

The most obvious difference between the victimological and the biosocial paradigms is the role of the child or adolescent. The biosocial paradigm sees the child or adolescent as an active interactant. This interactant role is not equivalent to saying that a child or an adolescent is making a free-will choice or is morally responsible for engaging in sexual behavior with an adult. It is a value judgement of the author of this chapter/editor of this volume that in any relationship in which there is a large dominance or power differential between the interactants, clearly, the more dominant and more powerful individual must accept full moral and
legal responsibility.

Sexual Attraction 

One cannot even begin to understand sexual behavior in any species, but especially in the human species, without including the term "sexual attraction." The term is broader in meaning than 
"mate choice" (Bateson, 1983), 
"sexual preference" (Bell et al., 1981), and 
“sexual choice"
(Remoff, 1984). 

Sexual attraction, too, is context dependent in the human species, in that attributes considered desirable in a sexual partner are not necessarily the same as attributes considered desirable in a marital partner. However, in either context, individuals usually are sexually attracted to other individuals who are neither too similar to nor too dissimilar from themselves.

Sexual attraction can be operationally defined as the

  1. awareness of or 
  2. attention given to or 
  3. behavioral association with or 
  4. courtship behavior displayed towards another specific individual
    or class of individuals (in person, representation, or fantasy) 
  5. that is associated with either observable or measurable physiological sexual arousal in the body of the perceiving individual.

Although there are modal, societal standards of sexual attractiveness for categories of individuals — e.g., sexually attractive adult male, sexually attractive adult female — individuals who represent the best examples of these standards cannot elicit sexual attraction in every adult of the opposite sex who is aware of and pays attention to them. 

John Money developed the concept "love map" to accommodate this idiosyncracy of individual sexual attraction. A love map is defined as follows:

". . . a developmental representation or template in the mind and in the brain depicting the idealized lover and the idealized program of sexuo-erotic activity projected in imagery or actually engaged in with that lover“ (Money, 1986, p. 290). 

The love map is discussed in more detail in the next section of this chapter, titled "The Love map," and in Money (this volume). In ethological conceptualization, the love map would be represented in the brain
by the stimulus filter [*2] (Lorenz, 1981).

The first four components of sexual attraction will be discussed separately in the remainder of this subsection, and the fifth component, sexual arousal, will be discussed separately in the subsection "Sexual Arousal," which concludes this section. 


The awareness of an individual or of a class of individuals must start with one’s noticing the presence of that individual or class of individuals. Certain stimuli enter or remain in one’s awareness more than do other stimuli, based upon 
the stimulus filters of innate releasing mechanisms, 
previous experience, 
the context, and 
the mood (Lorenz, 1981). 

It is reasonable to assume that there would be awareness of the presence of an individual or of a class of individuals towards whom there is sexual attraction, especially if a sexual context and mood were present. Sexual awareness usually is not noticeable or measurable by an outside observer.


Attention means 

"the sensory monitoring of the behavior of an individual or of a class of individuals either continuously or intermittently."

An individual does not have to be aware that he or she is being monitored. When individuals behave in such a way as to cause others (not sexually committed to them) to pay attention to them and when the basis of the attention is sexual attraction, such attention-eliciting behavior satisfies the functional definition of proceptive behavior (Moore, 1985). 

The acknowledgement by one individual that someone is paying attention to him or her is the beginning of communication (Smith, 1977). 

Communication becomes courtship when the attention between two individuals becomes 
both alternating and escalating and 
is accompanied by 
certain species-specific, mood-specific, stereotyped, proceptive expressive behaviors, as well as 
by mixed or alternating approach-and-avoidance eye-contact behaviors, which are the pre-adapted, adult/adult version of the culturally universal childhood-expressed game "peek-a-boo."

Behavioral Association

Behavioral association, the next indicator of sexual attraction, can take two forms: increased time or decreased space between two individuals. In both time and space, the association often starts under contexts and pretexts that do not reveal that, at least for one of the interactants, the underlying motivation is sexual attraction. One individual often increases behavioral association with another individual before any real communication or relationship has begun. 

Behavioral association is not a communicative interaction unless both individuals have acknowledged (vocally or non-vocally) that they are paying attention to each other. When it is communication, behavioral association is often used as proceptive behavior by both males and females.

In the special case of adult human sexual behavior with children and adolescents, social institutions that are founded on adult/child and adult/adolescent association, such as youth groups, are a proceptive means through which the pedophile (an adult who is sexually attracted primarily to prepubertal children) and the ephebophile (an adult who is sexually attracted primarily to adolescents’) can associate in a socially acceptable context with children and adolescents who are not related to the adult.

Courtship Behaviors

Courtship behaviors are a sequential, alternating and escalating series of species-specific, mood-specific, ritualized behaviors that signal mutual sexual receptivity (i.e., they are receptive-phase behavior) between two individuals (Morris, 1970; Tinbergen, 1960). 

Courtship is escalating intimacy over time where, in order for courtship to continue, the behavior of one interactant has to be responded to by the other interactant with escalation, rather than with de-escalation or with no response. 

Escalation signals the other interactant’s opportunity to escalate in return. De-escalation signals termination. No response and mixed messages (e.g., "Your words say ’no’ but your eyes say ’yes."') are ambiguous signals that test the intensity of the other interactant’s motivation.

Perper (1985), in a nonsystematic but nevertheless insightful way, describes four behaviors that compose the escalating temporal sequence of human receptive-phase courtship: 

  1. talk to each other, 
  2. turn in space, 
  3. touch each other, and 
  4. synchronize movements. 

Performed alone or without the specific sequence of 1, 2, 3 & 4, without alternation, and without escalation, these behaviors are not courtship and, therefore, are not predictive of ensuing human, inter-individual, conceptive-phase sexual behavior.

Sexual Arousal

At a purely physiological level, within the context of the Masters-and-Johnson-defined sexual response cycle, sexual arousal shows a definite cross-cultural commonality among all adults. There are some differences both within and between the two sexes, however (Masters and Johnson, 1966). 

(See Figure 1.1a and 1.1b. )

For example, the human female has the potential for multiple orgasms within a sexual response cycle and a greater variance in that cycle compared to the male. These differences are not of much significance in the understanding of the adult male sex bias in adult human sexual behavior with children and adolescents, however, because orgasm, which differentiates the male and female sexual response cycles, occurs during the conceptive phase of inter-individual sexual behavior. 

The adult male sex bias in adult human sexual behavior with children and adolescents is more a reflection of the proceptive-phase differences between males and females. 

Sexual arousal can be defined and measured by several different means, one of which is verbal self-report. Verbal self-report of sexual arousal may be accurate when one is sexually attracted to socially appropriate-age persons of the opposite sex. In all other cases, verbal self-report is highly suspect at best, inasmuch as it is very easy for the person making the self-report not only to deceive the person listening to the report but also to deceive him- or herself as well. 

In the case of adult human sexual behavior with children and adolescents, the inherent lack of certainty is especially true and is the reason for the use of penile plethysmography to measure and define sexual arousal (see Freund et al., 1989). 

The Love map

One’s own idiosyncratic love map (already defined in the previous section in the subsection "Sexual Attraction") is made up of the animate, inanimate, and contextual attributes, associated with other individuals, to which one is sexually attracted. Since love maps vary greatly among individuals, classifying some of the factors believed to contribute to love map variability may give insight into the yet to be fully understood determinants of adult human sexual attraction to children and adolescents.

Three sets of factors contribute to some of the love map variability:

  1. Two sources of stimulus familiarity — phylogeny [4] and ontogeny [5], 

  2. One property of the stimulus — the capacity to evoke initial-stimulus appetence [*6] in the perceiver, and 

  3. One property of the nervous system — stimulus discriminative

(The two properties will be discussed subsequently.)

The qualifying term "initial" is used before "stimulus appetence" because, after the perceiving individual’s initial encounter with a phylogenetically familiar or unfamiliar sexual-arousal-associated-with stimulus, [*8] previously unfamiliar and neutral, animate, inanimate, or contextual stimuli can be conditioned into ontogenetically familiar, sexually evocative status through pairing with the initial sexual arousal. 

The age at which one encounters conditioned sexual stimuli determines whether or not such stimuli will become part of the love map 

(see D'Udine, this volume, for early-age and Domjan, this volume, for late-age experimental animal models). 

This sexual-conditioning effect will be discussed in this chapter in regard to adult heterosexual males.

For reasons that will be explained later in the chapter, the human male love map is largely coded and stored in a visual format. The analysis of visual stimulus patterns and their sexual relevance is processed in neural tissue whose response to both familiar and novel stimuli will vary among individuals, based on genetic differences in the reactivity of the tissue itself as well as on previous exposure of the tissue to stimuli with varying degrees of phylogenetic or ontogenetic familiarity to the perceiving individual. 

Whether or not the familiarity is on the basis of 

phylogeny (known by the species, historically) or 

ontogeny (known by the individual, developmentally) 

has an effect on the capacity of a stimulus to evoke initial-stimulus appetence. 

Phylogenetically familiar stimuli, such as the shape of a nubile [*9] female, evoke a higher degree of initial-stimulus appetence but have a lower degree of stimulus discriminability; in contrast, ontogenetically made-familiar sexual stimuli, such as a particular pattern of lace evoke a lower degree of initial-stimulus appetence but have a higher degree of stimulus discriminability 

(see Figure 1.2). 

Ontogenetically made-familiar stimuli, such as lace, which evoke low initial-stimulus appetence, can be incorporated into an individual’s love map, however, as will be discussed in relation to "secondary-stimulus appetence".

Capacity of a Stimulus To Evoke Initial-Stimulus Appetence

The stimuli that have a capacity to evoke a high degree of initial-stimulus appetence in a perceiver are not arbitrary. Rather, they derive from those attributes whose variations, over eons of evolutionary time (i.e., through phylogeny), have been associated with variance  in fitness and about which the species already is familiar. Initial stimuli that have affected fitness positively over eons of evolutionary time usually evoke a high degree of initial-stimulus appetence.

There appear to be two major attributes some of the variations of which evoke initial-stimulus appetence: biological age and sex (usually perceived as gender attributes). That is, the two most fitness-relevant attributes in a potential sexual partner are the age of the individual and the sex of the individual. Evolution should have shaped human populations so that the "average adult male" has an initial-stimulus appetence for the attributes found in nubile females. Surely, the average adult male’s genetic  material has encountered this combination of attributes before, and adult males who attended to these attributes perceptually left more offspring than did adult males who ignored them.

Stimulus Discriminative Ability

Initial-stimulus appetence evolved so that individuals would be attracted to those attributes whose variations positively affected fitness in those individuals’ evolutionary past. However, stimuli usually are complex, and to attend to those features of stimuli that are associated with optimal fitness requires that the degree of stimulus discriminative ability be optimized.

Stimulus discriminative ability, in this context, is a measure of the degree to which the numerous animate, inanimate, and contextual attributes of, or that are associated with, another individual can be matched to the numerous attributes in the prototype of one's love map, with the assumption that the closer the match, the more the eroto-sexual attraction. Stimulus discriminative ability is primarily a measure of the ability of the perceiving individual’s nervous, system to discriminate — it is not a property of, but may be limited by the discriminability of, the stimulus. 

Since in humans the love map is constructed in early childhood and does not become activated in the service of fertile mating until several years later, it is unlikely that any new individual ever could completely resemble the love map in all animate, inanimate, and contextual attributes. 

If stimulus discriminative ability as a perceptual/physiological trait is
distributed normally in the population (as a first-order approximation), there
will be some individuals whose stimulus discriminative ability will be lower
than optimum (left half of curve in Figure 1.3) and other individuals whose stimulus discriminative ability will be higher than optimum (right half of curve in Figure 1.3), so that the "average male" (center of curve in Figure 1.3) will have the optimum degree of stimulus discriminative ability. [*10]

Individuals with higher than optimum stimulus discriminative ability can attend to minor details in the attributes of and associated with other individuals when appetitively searching for individuals who fit their
love map. 

These individuals often have a sexual attraction to very specific, ontogenetically made-familiar, conditioned sexual stimuli, inasmuch as phylogeny can code only generalities in the innate stimulus filters of the recipient. In ontogeny, the degree to which a conditioned sexual stimulus can be discriminated (i.e., made to match the love map) is limited only by the discriminative ability of the perceiver and the discriminability of that which is being perceived. 

A secondary-stimulus appetence can develop for a sexually conditioned, early in development encountered, ontogenetically made-familiar animate, inanimate, or contextual attribute in the love map, such as lace or black leather, whose potency can be as strong as or stronger than the initial phylogenetically familiar stimulus [*11]. 

An early in development encountered, ontogenetically made-familiar, highly potent secondary stimulus, such as an inanimate attribute, that evokes a strong secondary-stimulus appetence is called a paraphilic [*12] "fetish." 

The development of strong secondary-stimulus appetences can occur because, once the phylogenetically familiar stimulus has been optimized for fitness, stimulus potency increases with stimulus discrimination, as will be shown subsequently. 

Some paraphiles can appetitively discriminate sexual stimuli to such a degree, i.e., search for and find the stimuli that very closely resemble the attributes in their love maps, that the stimuli have extraordinary, addiction-like, idiosyncratic sexual potency. Sexual-stimulus discrimination is the mechanism by which type paraphilias develop, and the propensity to develop them is correlated functionally with sexual stimulus discriminative ability and, mechanistically, with the degree to which the brain is defeminized in utero, as will be developed later in this chapter in the section titled "Adult-Child and Adult-Adolescent Sexual Behavior Versus Sexual Abuse." 

Some pedo- and ephebophiles, who are sexually attracted to the highly discriminable, visual animate attributes of very particular stages of development of hairless or of budding secondary sexual characteristics, respectively, are thus attracted to children and adolescents on the basis of a type paraphilia. 

Individuals who are endowed with lower than optimum stimulus discriminative ability (see left half of curve in Figure 1.3) attend only to major generalities in the phylogenetically familiar attributes of other individuals when appetitively searching for individuals who fit their love map. These appetitively searching individuals have an attraction only to phylogenetically familiar stimuli, inasmuch as ontogenetically made-familiar, conditioned stimuli cannot become potent enough in themselves to elicit sexual arousal because these individuals’ low discriminative ability does not allow them to move to the right half of the curve in Figure 1.3. These individuals can increase the potency of sexual stimuli only through searching for supra-normal stimuli.

Supra-normal Stimuli

In addition to increasing as a result of increased stimulus discrimination, stimulus potency also increases when attributes become "supra-normal stimuli" (Tinbergen, 1951), where the stimuli are phylogenetically familiar  but are supra-normally exaggerated in size (i.e., extra large or extra small) and are therefore more potent.

(See Figure 1.4.)

Attraction to supra-normal stimuli is the mechanism by which size  paraphilias develop. For reasons that will be mechanistically developed later in the chapter, individuals whose brains are highly masculinized are sexually attracted to the submissive aspects of "smallness," whereas individuals whose brains are highly unmasculinized are sexually attracted to the dominant aspects of "largeness." Some pedophiles, who are sexually attracted to the smallness of the whole child or to the child’s primary or secondary sexual characteristics, fall into the category of size paraphiliacs.

Degree of Stimulus Discrimination, Stimulus Fitness, and Stimulus Potency 

There is a relationship between the three variables —

degree of stimulus discrimination, 

stimulus fitness, and 

stimulus potency

— that is shown in Figure 1.5.

Although it may be limited by the discriminability of the stimulus, the degree of stimulus discrimination is reflective of one’s innate stimulus discriminative ability and is the independent variable. Based on the degree of stimulus discrimination, an individual would obtain varying degrees of stimulus fitness and stimulus potency, which are considered to be the dependent variables.

Stimulus Fitness 

Stimulus fitness is the effect on overall, lifetime fitness of one's being sexually attracted to naturally found stimuli using a given level of stimulus
discrimination. The most general attributes that the average heterosexual
male would attend to in locating a fertile individual — female sex and
reproductive age -- would require a very low level of stimulus discrimination. 

Female sex and nubile age would require a higher level, followed by 

female sex, nubile age, and good health; 

then female sex, nubile age, good health, and high status; 

then female sex, nubile age, good health, high status, and good education; 

and so on. 

Because of the potential for an almost never-ending range in the degree of stimulus discrimination (i.e., the degree to which the stimuli match the prototype in the love map), there obviously is an optimum degree of stimulus discrimination that optimizes fitness in the perceiving individual.

The degree of stimulus discrimination must be optimized in order that fitness be optimized in the average human male, because being too indiscriminate could lead to sexual attraction to individuals who were not even the opposite sex and fertile. Being too discriminate, conversely, could lead to the male’s turning down potential opportunistic matings. It is assumed that the reproductive strategy that evolved and optimized human male fitness protects and helps provision the offspring of the best fertile female who chooses him as a mate (see Remoff, 1984) and, at the same time, allows the male to not down uncommitted mating opportunities with other willing fertile females (Daly and Wilson, 1983; Symons, 1979).

Stimulus Potency

Stimulus potency reflects the amount of stimulus necessary for achieving a standard response, such as a certain degree of measurable sexual arousal. Stimulus potency is analogous to the pharmacological use of the term "potency," as in "drug potency." 

The relationship among stimulus potency, stimulus fitness, and degree of stimulus discrimination is shown graphically in Figure 1.5. Note that as the degree of stimulus discrimination increases (i.e., the stimulus increasingly resembles the love map), stimulus potency initially decreases and then increases, because   the basis of discrimination switches from phylogenetic to ontogenetic familiarility at the top, of the bell-shaped curve in Figure 1.5.  

For example, a particular nubile female will deviate from the ideal nubile female phylogenetic prototype the more in detail she is perceived, which is why her stimulus potency actually decreases from the perceptual idealization in the left-hand corner to  the perceptual reality at the top of the curve in Figure 1.5

However, the potential resemblance of a particular female to idiosyncratic, ontogenetically made-familiar, conditioned stimuli or attributes in the love map means that stimulus potency can potentially increase as stimulus discrimination increases on the right-hand side of Figure 1.5.  

This situation would occur when both the particular female and the prototype female in the love map have idiosyncratic animate or inanimate attributes or contexts in common. The more the resemblance, the higher the degree of stimulus discrimination and the higher the potency.

Natural selection has maximized stimulus fitness when stimulus potency (of a particular stimulus/attribute) is minimized with the result that attraction to appropriate (multi-stimulus/-attribute) individuals rather than to isolated stimuli or attributes of individuals is insured.

As is shown in Figure 1.6, there is a positive correlation between the number of near [*13] optimally-discriminated-for-fitness stimuli or attributes and the total stimulus potency or overall desirability of an individual.

A perceived individual in whom many stimuli or attributes were near optimally-discriminated-for-fitness could have a higher total stimulus potency or overall desirability value to a perceiving individual than another individual in whom only one stimulus or attribute was nearly maximally discriminated. 

The ability to maximize stimulus potency by minimizing or maximizing stimulus discrimination (i.e., the two tails of the curve in Figure 1.5.) is the mechanism by which males, more so than females, can dissociate sexual eroticism (potency is maximized) from erotic affectual bonding (fitness is potentially maximized) from erotic affectual bonding (fitness is potentially maximized). 

Males accomplish this by perceptually focusing on one highly discriminated animate, inanimate, or contextual stimulus (attribute) that closely resembles their love map. In contrast, the steep rise in the slope of the curve in Figure 1.6, once a critical number of near optimally-disriminated-for-fitness stimuli have been accrued, reflects the potentially fitness maximizing process of forming an erotic affiliative bond with an individual (i.e., "falling in love") rather than merely being sexually attracted to an individual’s attributes.

Relationship to Love

Someone’s idiosyncratic love map is that individual’s ideal representation of another individual with whom the first should fall in love.

This concept is true even if, through variable hormonal or life experience, the latter individual is not of the complementary sex or is not fertile. [*14]

Whereas one can perform sexual behavior with a wide variety of individuals, one can fall in love only with an individual whose attributes closely resemble the attributes in one’s love map.

For some adult males, the age of individuals in their love map, for reasons that will be partially explained in this volume, is the age of children (pedophilia) and adolescents (ephebophilia).

The erotic love of children and adolescents by an adult has three characteristics that differentiate it from the usual type of adult-adult love:

  1. The love between the adult and the child or adolescent is not necessarily of the same kind to both of them.

  2. There is a very limited time during which the love can remain erotic for the adult.

  3. The child or adolescent can be an extremely potent sexual stimulus for the adult.

Adult-Child and Adult-Adolescent Sexual Behavior within the Context of Reproductive Behavior

Reproductive Behavior

Philosophers, biologists, and theologians of all persuasions have struggled with the question, What is the purpose of life? If one looks for the common element in all of their writings, one would find the conclusion that the purpose of life is to propagate life. The process by which life propagates life is called "reproductive behavior," and because the process expands on the purpose, that process is important to all individuals in a society, including pedophiles, ephebophiles, and even chaste celibates.

Reproductive behavior is not simply sexual behavior that is open to the possibility of or results in pregnancy! Reproductive behavior can be defined as

"any behavior that promotes one’s genetic propagation."

Sexual behavior (e.g., copulating) accomplishes only a small part of reproductive behavior. Humans, in contrast to many simpler forms of life, are required

to carry a pregnancy to term,

to give birth to a live infant, and

to provide a large amount of bi-parental care in order that an offspring be raised optimally to an age at which that offspring can genetically propagate.

Nonsexual Reproductive Behavior

One of the most important contributions from the field of sociobiology—which is the synthesis of ethology, population genetics, and behavioral ecology—has been the concepts 

"inclusive fitness"" (Hamilton, 1964) and 

"kin selection"“ (Smith, 1964). 

These concepts are especially important in the understanding of the nonsexual reproductive behavior of individuals who sexually reproduce themselves at a less-than-average rate. 

However, one should not assume that pedophiles and ephebophiles or individuals who engage in pedo- or ephebo-sexual behavior fall into this category, since the relevant data for making such a determination have not been collected. 

Inclusive Fitness and Kin Selection 

The concepts "inclusive fitness" and "kin selection" developed when biologists tried to understand the "purpose of life" of sterile castes of insects. Another, slightly different way of asking the same question would be, “why would individuals in a sterile-insect caste work to care for a brood that  reproductive behavior is getting one's genes into the next generation, irrespective of whose genitals make the transfer. 

For example, if as a result of meiosis, there are 50% of an adult’s genes in every one of his or her own offspring, then there are 25% of an adult’s genes in every one of his or her nephews and nieces. Helping a relative’s offspring is almost as beneficial in relation to evolution as is helping one’s own offspring, whether the relative is a bee or a human. 

Since pedo- and ephebophilia (and pedo- and ephebo-sexual behavior) sometimes involve socio-sexual behavior between relatives, it is a testable hypothesis that such behavior evolved through mechanisms of kin selection by raising the inclusive fitness of one or both of the interactants 

(see Anderson and Bielert, this volume; Taub, this volume; de Waal, this volume). 

Kin selection may be a mechanism by which pedo- and ephebophilia evolved, because adult human males evolved in the presence of related children and adolescents. In the hunter-gatherer bands in which humans evolved, under conditions in which nubile females changed bands, an adult male would be related to the majority of children and adolescents encountered in his natal band. 

Kin selection also could have been involved under the alternative condition in which reproductive-age males changed bands, because a non-procreative "alternative strategy" for some (pedo- and ephebophile) males would be to stay in their natal band and assist their sister’s offspring, to whom they also are genetically related." (See Pusey, this volume.) 

Thus, pedo- and ephebophilia could have evolved by mechanisms associated with kin selection but, in larger modern societies, now involve relationships between adult males and children and adolescents to whom the males are not genetically related.

Of course, alternative hypotheses are that

[1] pedo- and ephebo-sexual behavior are the results of non-selected random mutation or genetic drift

[2] or are simply a by-product of selection for some other trait, such as heterosexuality.

These hypotheses will be developed in the subsection "Pedo- and Ephebophilia," which is found later in this chapter. 

(See Gould and Lewontin, 1979.)

Finally, [3] pedo- and ephebo-sexual behavior may be psychopathological, maladaptive responses to mental derangement or social dysregulation and may actually lower the fitness of both of the interactants. In the absence of conclusive data allowing the refutation of any of these hypotheses, it is reasonable to at least discuss and eventually test them all.

Random change [1] and the by-product hypothesis [2] are difficult to test and refute. There are not enough demographic data to test the genetic drift hypothesis, but it is a reasonable hypothesis, inasmuch as parental investment and care are not distributed equally among geographically diverse societies.

[1] The "adaptationist" (also known as "selectionist") hypothesis will be discussed in this section;

[2] the by-product hypothesis will be discussed in the subsection “Pedo- and Ephebophilia," referred to previously on this page; and

[3] the pathology hypothesis will be discussed in the subsection "Harm,"
which is found in the section "Adult-Child and Adult-Adolescent Sexual Behavior Versus Sexual Abuse."

Inclusive fitness and kin selection are related to reproductive behavior, which, from a biosocial perspective, can be divided into

(a) mating effort,

(b) parturition, and

(c) parental investment (see Betzig et al., 1988).

Whereas it is difficult to conceptualize adult human sexual behavior with children and adolescents as having much to do with parturition, aspects of both mating effort and parental investment appear to be involved and will be discussed subsequently, following a brief discussion of some of the functions of non-procreative sexual behavior.

Non-procreative Sexual Behavior

Sexual behavior that is non-procreative is "possible" only if one does not assume that all sexual behavior is "practice" and that such practice eventually facilitates heterosexual, procreative intercourse, i.e., mating.

Non-procreative sexual behavior among humans appears to have two major
adaptive functions:

affiliation and

drive reduction.

Affiliation also is called "attachment" (Bowlby, 1969) and "bonding." See Eibl-Eibesfeldt (this volume) for a discussion of affiliation, attachment, bonding, and love. There also are minor, culturally transmitted, society-specific functions, such as occur

in Polynesia (Diamond, this volume) and

in Melanesia (Schiefenhovel, this volume).

Among pygmy chimpanzees (bonobos), it is fairly clear that another function of sexual behavior is inter-individual tension regulation (de Waal. this volume).


The affiliative function of non-procreative sexual behavior in humans is proposed because most human sexual behavior between two opposite sex, fertile individuals is not open to procreation. As a result of concealed ovulation and continuous sexual receptivity, the human female affords the human male the time and opportunity to form an affiliative bond with her. A bonded male is more likely to help protect and provision young offspring than is a non-bonded male.

Because of the context in which inter-individual sexual behavior evolved, one outcome of a protracted sexual relationship between almost any two individuals (of any sex or age) is a certain degree of affiliation. If affiliation is considered as being a primary drive, separate from sex and hunger (Bowlby, 1969), then for some adults, one potential functional outcome of sexual behavior with children and adolescents is affiliation with them (see Dienske, this volume).

Drive Reduction

Humans are a very sexual primate, with a sex drive that often surpasses their copulatory opportunities. This condition creates another function of orgasmic human sexual behavior: the reduction of the sexual drive while one is engaged in behavior that is not even open to procreation.

Non-procreative sexual behavior includes most non-contracepted and all
contracepted heterosexual intercourse, some types of self- as well as mutual
masturbation, fondling, and homosexual, heterosexual, and pedo- and
ephebosexual behavior.

Adult-Child and Adult-Adolescent Sexual Behavior as Mating Effort

Because males and females have such different reproductive strategies, the question, 'Can aspects of adult-child and adult-adolescent sexual behavior be, or be derived from, mating effort?' will be considered, first in adult males and then separately in male and in female children and adolescents.

Because of the ages and the relationships of the interactants who are addressed in this volume, mating effort and parental investment, two components of reproductive behavior, are not as easily separable as they would be with other interactants.

Adult Males

Sexual behavior between an adult male and a male or a female child or adolescent could be actual mating effort for the adult male if

(a) an adult male impregnates an adolescent female or

(b) an adult male uses pedophilic and ephebophilic affiliative behaviors to demonstrate high, non-overtly sexual, paternal-investment-like qualities to the child’s or adolescent’s mother and, thereby, gains sexual access to her as a form of sexual selection on her part.

This male strategy has been suggested for some species of baboons as well as for humans.

It is also possible that, in regard to the adult, adult-child and adult-adolescent sexual behavior derives from mating effort. The "object" of one's sexual desires may be under the control of open genetic programs [*18] that specify relative age and relative gender of individuals towards whom one is attracted but that are under (natural) selection pressures to allow individual life experience to influence the specifics of mate selection (see D’Udine, this volume).

Male Children and Adolescents

There certainly was a time in the history of Western civilization when adult male tutors and their young male students learned more than the new Pythagorean theorem together (see Bullough, this volume). In ancient Greece, adult male tutors experientially taught their pubescent male students  about genital sexual behavior, and parents sought out the best teacher they could for their sons.

Even today, there is some evidence that male-adult---male-child and male-adult---male-adolescent sexual behavior may be more prevalent but less reported than similar behavior with female children and adolescents (Abel et al., 1987).

Such sexual behavior could be considered mating-effort practice for the younger interactant, but there is no published evidence that such practice is needed or increases later fitness.

Female Children and Adolescents

To an adolescent female, the same "practice" that may make an adolescent male "perfect" can easily make her pregnant. However, in terms of mating effort, adolescent pregnancy (but not necessarily single, non-kin-assisted parenthood) may be an adaptive reproductive strategy for some socio-economically disadvantaged females in socially stratified, industrialized societies, given their limited reproductive options

(Draper and Harpending, 1982; Harpending et al., 1987; Lancaster and Hamburg, 1986; Lancaster et al., 1987).

In many pregnancies among socio-economically disadvantaged adolescents, the fathers contribute little if anything to the provisioning of the offspring. As a result, to these female adolescents the important male attributes would be the ones that could be transmitted genetically. Male age would not be a factor except that older males would have had more of a chance to demonstrate their genetic worth than would younger males.

If the sexual behavior is both procreative and incestuous [*19]

(sexual behavior between two first-degree relatives, who are related to each other by 1/2),

the detrimental effects of inbreeding are of almost as much biological significance to the adult male as they are to the potentially fertile, adolescent female, since the reproductive success of both of them is dependent upon the fitness of the same progeny.

As a result, there are biological mechanisms that prevent natural fathers and their daughters from being sexually attracted to each other at any age

(see Parker and Parker, 1986; Shepher, 1983; Wolf and Huang, 1980; Pusey, this volume) [*20].

It is a testable hypothesis that in incestuous as well as in non-incestuous, but nevertheless related individuals (e.g., uncles, grandfathers, cousins), non-procreative (i.e., non-coital) sexual behavior between an adult male and a related female child or adolescent could increase the inclusive fitness of both the adult male and the female child or adolescent, by hastening the female child’s or adolescent’s onset of actual reproduction.

Weakly in support of this hypothesis is the finding that socio-economically disadvantaged females, who make up the bulk of females having teenage pregnancies, are reported in numerous studies to be involved sexually during their childhood and adolescence with both related and non-related adult males more than are non-socio-economically disadvantaged females (e.g., Finkelhor, 1984). The sampling biases of socio-economic class as well as numerous intervening variables make this correlation open to numerous interpretations, however.

If an offspring were produced by an adult male and an adolescent female who were related to each other by 1/4 - 1/8, the inclusive fitness of both of them would be maximized. This outcome predicts a high degree of sexual attraction and behavior between adult males and nubile females who are distant relatives.

It has been proposed that there is a critical period in the psychosexual development of adolescent females during which time the female, through an open genetic program, learns by imitation of her mother the most adaptive reproductive strategy to pursue (Draper and Harpending, 1982). If this notion is true, then it requires that the adolescent female have a more than passive role in determining her own reproductive destiny.

Adult-Child and Adult-Adolescent Sexual Behavior as Parental Investment

Trivers (1972) defines parental investment as

"any investment by the parent in an individual offspring that increases the offspring’s chance of surviving (and hence reproductive success) at the cost of the parent’s ability to invest in other offspring."

In some well-studied species of non-human primates, there is evidence that adult-juvenile sexual behavior may be type of parental investment

(Anderson and Bielert, this volume; Hopf, 1979).

It is a fact that, among humans, some adults sexually interact with children and adolescents, including children and adolescents who are relatives. This subsection is simply exploring parental investment as a "biological motive" for this behavior.

There are two basic questions:

1. Can any aspect of adult human sexual behavior with children and
adolescents be parental investment today? and

2. Do aspects of adult human sexual behavior with children and
adolescents derive from behavior that was parental investment in
humans’ evolutionary past?

Currently, data are not available to answer these two questions definitively.

Nevertheless, some of the components of parental investment, collectively
called "nurturing behavior," are seen in both pedo- and ephebophilia and
can be considered and discussed as

(1) comforting and contact,

(2) feeding,

(3) grooming,

(4) protecting, and

(5) teaching,

in the effort being made to answer these questions.

[1] Comforting and Contact Behavior

Comforting and contact behavior to conspecifics (members of the same species) appears to be a basic characteristic of adult humans; with adult females comforting and contacting infants more than adult males do. Males, however, also contribute to comforting and contact of children and adolescents.

Comforting is a type of bodily contact that involves caressing and rocking or patting movements, often with the body of the comforter and of the individual being comforted moving or swaying in unison, which is the phylogenetically pre-adapted origin of the synchrony, or matching phase, of adult-adult courtship.

Fondling, which is one of the most frequent pedophilic behaviors, uses the same motor patterns as comforting behavior — i.e., caressing and so forth — but is associated with sexual arousal, at least on the part of the fondler.

Young children (ages 3-6) actively seek, more than give, comforting behavior. Children that comfort tend to be female rather than male, and they tend to be over 6 years of age.

Among many non-human primates (e.g., rhesus and pigtail macaques), the ability to parent successfully in adulthood is contingent upon parent- (or
parent-surrogate-) contact behavior during childhood. In the squirrel monkey (Saimirr), captivity-raised individuals of both sexes in mixed-sex peer groups were not even able to conceive unless they had been allowed, when they were juveniles, to have sexual contact with opposite-sex adults (Hopf, 1979, personal communication). It is reasonable to expect, therefore, that human infants and children should be selected (by natural selection) to first elicit and then actively seek comforting behaviors from adults. These outcomes, indeed,  are what are found.

Regarding the adult male who is sexually aroused by comforting types of behavior with a child or an adolescent (i.e., fondling), if Trivers’s definition of parental investment is used, such behavior can be considered to be actual parental investment on the part of the adult male only if

(a) the child or adolescent is a biological relative and 

(b) the sexual behavior improves the future reproductive success of the child or adolescent and 

(c) the investment (in time and energy) by the adult male is taking away a resource from a sibling or another close relative. 

That these criteria will be met is possible in some female children and adolescents who are pursuing an early-mating-effort type of reproductive strategy. 

(However, it is improbable that these criteria will be met — as has been discussed in this section in the subsection "Female Children and Adolescents," which is found in the greater subsection "Adult,-Child and Adult/Adolescent Sexual Behavior as Mating Effort")

[2] Feeding

Since it is quite natural for adults to provision and feed children and adolescents and since such adult-child and adult-adolescent feeding behavior is the pre-adapted, phylogenetic origin of part of adult-adult courtship ritual, it is easy to see how the feeding and provisioning of children and adolescents could predispose some adult males to sexual behavior. 

Feeding and mating have functional proximity [*21] in the hierarchy of behavioral
organization. In true pedophiles and ephebophiles, feeding often plays a major role in the proceptive and receptive phases of their courtship behavior. 

The public image of the "child molester" who with candy lures children who are strangers to him from playgrounds into sexual activity is legend, but this image describes the behavior of a pedosexual psychopath more than the behavior of a true pedophile. 


Grooming behavior, in the context of parental care, consists of the bodily care behaviors that an adult does for a child, such as cleaning after elimination, bodily washing, and skin, hair, and nail care. In nonhuman primates, both kin and non-kin social bonds are formed and reinforced by grooming, and there is a very predictable species-specific pattern of who grooms whom.

Adult humans groom each other’s hair and massage each other for a variety of reasons including relaxation, social intimacy, affiliation, and sexual gratification. One effect or potentially adaptive function of grooming, for whatever stated motive, is that it puts two individuals (the groomer and the groomed) into intimate physical contact with each other, contact that is similar to the physical proximity of parent and child or of two adult individuals engaged in the intimate, physical contact stage of courtship.


Young of all species, whether prey or predator, are not able to care for themselves to the same degree that adults of the same species are. Therefore, in all species in which there is parental care, the mother protects the young. In fact, in multimale species [*22] of primates, such as humans, all adult males of the social group, at least to some degree, protect all of the young. This behavior is especially well developed in some of the higher primates (see Mackey, this volume; Taub, this volume). 

The same motor patterns in the same context are used by adult human males to protect both adult females and their young offspring. These aggressive motor patterns must lie in relative “functional proximity" to sexual motor patterns to the degree that they are both associated with adult females. As a result, protecting children and adolescents may facilitate a sexual mood in some males who have the other preconditions for pedo- or ephebophilia. As a corollary, being in a sexual mood may, in some males, facilitate feelings of wanting to protect younger or weaker members of the social group. 


The higher an organism is on the phylogenetic scale, the greater the role is of individual as well as social or observational learning. In associational learning, which usually occurs in the lone individual (and by means of which the individual is "self-taught"), previously neutral stimuli can become associated with reward or reinforcement and acquire the capacity to elicit responses. 

Observational learning, which is present in some birds and all primates and is the major mechanism of cultural transmission, also is a means of "self-teaching" in that there need not be any intent to teach by anyone, even though social association is required. In humans, the concept "teach" implies a deliberate modification of another individual’s behavior. To some degree, all human parents teach their children. 

In simple societies, most of what a child has to learn to become an adult can be taught by its parents. However, in more complex societies with a specialized division of labor, children and adolescents are taught by professional teachers who have parent-like relationships with their students. The professional teacher/parent surrogate, therefore, has an intimate relationship with a child or an adolescent to a degree that used to be reserved for a biological parent. 

Adults can teach and give children and adolescents skills and resources for upward social mobility as well as teaching them pedagogical facts. In a sample of male androphilic (andro = male sex; philia = love of) pedo- and ephebophiles involved in ongoing sexual relationships with 11- to 16-year-old males, the pedo- and ephebophiles came from significantly higher socio-educational levels than did the young males’ fathers or stepfathers (Sandfort, 1981). 

In numerous industrialized Western metropolises, there is a documented tradition of wealthy male patrons "subsidizing" lower socioeconomic status pubescent males in return for sexual favors. The sexual component of the more traditional teacher-student relationships of ancient Greece is legend to the extent that pedo- and ephebophilia often are called “Greek love.“ 

Because the previously discussed inbreeding-avoidance mechanisms, which protect children and parents from becoming sexually attracted to each other, would not operate with teachers and their students, all such mentoring types of relationships are at risk of becoming sexual. 

Comparison of Pedophiles and Ephebophiles to Individuals with Other Age and Sexual Orientations Throughout the Life Span 

Coding and Storing of the Love map 

Some attributes that compose the human love map are amenable to being coded and stored in the brain on the basis of their structure: shape, texture, color, movement, and odor. It will be shown that although males primarily code and store the attributes that compose their love map on the basis of structure, there are other attributes composing the love map in males that are coded and stored in a nonstructural way that first requires processing at a higher level of neural integration. 

The female love map is not primarily coded and stored on the basis of structure; rather, attributes are coded and stored in such a way as to first require processing at higher levels of neural integration. 

How the attributes of the love map are coded and stored in neural tissue, i.e., whether they are coded and stored on the basis of structure or processed at a higher level of neural integration first, has a profound effect on the capacity of the attributes of the love map to act as sexually provocative stimuli to which other, previously neutral stimuli can be conditioned to sexually evocative status.

Attributes that can be stored as part of the male love map on the basis of their structure can act as conditioning agents (i.e., unconditioned stimuli) much more so than can attributes whose coding and storage first require processing at higher levels of neural integration. Because their love map comprises structurally coded and stored attributes, it is males more than females in whom resides the capacity for the conditioning of an array of previously neutral, animate, inanimate, and contextual, structurally codable and storable stimuli to sexually evocative status. [*23]

Each new structurally codable and storable stimulus in the array that is conditioned to sexually evocative status will be slightly less potent and, therefore, have slightly less capacity to similarly condition other, previously neutral stimuli.

A hierarchy of sexually evocative, animate, inanimate, and contextual stimuli is created, with each stimulus that is closer to the actual love map having more sexually evocative potency. This hierarchy-building process is one of the neuro-ethological mechanisms by which an appetitive behavior (searching for a female mate) eventually leads to a consummatory behavior (mating) in a heterosexual human male. This process also is one of the neuro-ethological mechanisms that underlie male, more so than female, proneness to paraphilias.

According to the theory of the love map (Money, 1986), the initial stimuli that make up the human male love map are acquired in early childhood, well before puberty. As part of the acquisition process, certain aspects of the love map, such as the relative age and gender of individuals towards whom one is sexually attracted, are partly innate; other aspects of the love map itself, such as idiosyncratic, specific preferences, are almost entirely dependent on individual life experiences.

Obviously, life experiences vary from male to male. Similarly, there is every reason to believe that, as a result of genetic variability and of intra-uterine hormonal variability, the innate elements of the love map, too, are different in different males. 

As was noted previously, the love map comprises attributes that are coded and stored in two ways: 

(1) on the basis of the attributes’ perceived structure and 

(2) on the basis of non-structurally perceived and processed properties. 

Each type will be considered separately in human males and in human females.

Coding and Storing Attributes on the Basis of the Attributes’ Perceived Structure

Human Males 

In many male mammals, the main attribute composing the love map is odor, an attribute that is coded and stored on the basis of its structure. In the human male, olfaction plays a lesser role in the composition of the love map than does vision

In human adolescent and adult heterosexual males, the main attributes that are coded and stored in the love map on the basis of the attributes’ perceived structure are the proceptive expressive movements and the shape of the nubile female. 

In addition, also coded and stored on the basis of their perceived structure are the ontogenetically made-familiar animate and inanimate objects and contexts that have been conditioned to sexually evocative status early in development. 

The reason why adult heterosexual human males are visually attracted to the proceptive expressive behavior (movement) of (any) adult female and the degree to which the attraction is innate or is conditioned through life experience is not completely understood. However, because the attraction is to the structurally perceived proceptive expressive behavior, aspects of which look very similar cross-culturally, there is a strong suggestion that both the behavior in heterosexual females and its reception by the stimulus filter in heterosexual males are under the influence of rather closed genetic programs. There appears to be a reciprocal relationship between the degree to which one is perceptually attracted to these feminine proceptive expressive behaviors in others and the degree to which one exhibits the behaviors oneself. 

In addition to the attraction to the perceived structure of feminine proceptive expressive behavioral movement, the adolescent and the adult heterosexual male, as has been mentioned, also are attracted to the shape of the (any) nubile female. The degree to which this attraction is innate or conditioned, too, is not known. However, it takes a very small amount of stimulus discriminative ability for a heterosexual adolescent or adult male to recognize the easily discriminable shape, [*24] and once recognized, the shape has high stimulus appetence. 

(See Figure 1.7a.) 

The visual vulnerability of human males to the sexual conditioning of ontogenetically made-familiar animate and inanimate objects and contexts is exploited by the garment industry in the industrialized world. The industry ~ has made lace a sexually dimorphic, female fabric (i.e., an inanimate object) "K that has been conditioned speci?cally to sexual arousal by being used almost exclusively on adult female lingerie and bridal gowns. 

(See Figure 1.7b.) 

Lace has visually complex, highly discriminable patterns embedded within patterns, and in order to see the inner patterns‘ (requiring high discriminative ability), one has to fix one’s gaze. When lace is put on and around animate sexual releasers, it takes on sexual releasing properties itself through conditioning. Lace can be incorporated in the love map if encountered early enough in development. There is nothing intrinsically feminine or sexual about lace. 

The attraction (initial or through conditioning) of the human male of the industrialized West to the sexually dimorphic smell of female-worn perfume and the feel of female-worn, sexually dimorphic fabrics of silk, nylon, and satin also are further evidence of the male’s coding and storing capacities on the basis of the stimuli’s perceived structure, using olfactory and tactile senses. 

The attributes (shape, texture, color, movement, and odor) to which males are attracted (either initially or through conditioning) are not random; rather, such attributes have phylogenetic significance: e.g., genital odors = musk-derived perfumes; smooth skin of youth = silk, nylon, and satin. 

The difference between normalcy and minor paraphilic fetishes in this regard, among adult heterosexual males, is one of degree (see D’Udine, this volume; Domjan, this volume). 

Human Females 

In many birds, the attributes in the female love map are coded and stored on the basis of perceived structure in a visual format, which is why the males of so many bird species are brightly colored. In human females, for reasons that will be explained, visual attributes appear to play a lesser role in sexual attraction — and, therefore, in the coding and storing in the 1ovemap — than they do in human males. 

What human females, more so than human males, appear to store on the basis of visual-structural properties within their sensory-perceptual stimulus filters is the nonsexual "infant/child schema," first conceptualized by Lorenz in 1943 (see Lorenz, 1981). The degree to which the attraction to the schema is innate or conditioned is not known. 

Infants and children have a characteristic shape to the face, with a high forehead and puffy cheeks, and relatively large eyes and a large head relative to the size of the body. The phylogenetically familiar infant/child schema requires a very small amount of stimulus discriminative ability in order that the shape be recognized, and once recognized, the shape has high stimulus appetence. 

(See Figure 1.8.) 

In comparison with males, females look more at (any) infants, have more autonomic arousal when they look at (any) infants, and are more attentive to (any) infants. Because affiliation to a particular infant on the part of the mother is more important at birth than is affiliation to a particular infant on the part of the father, female affiliation may be influenced by more closed genetic programs than is male affiliation of this kind. 

This predisposition toward becoming affiliated with one’s infant probably works through an innate female attraction to the (any) infant schema, as was just discussed. The actual affiliation process between an adult female and a particular human infant is, of course, a postpartum process that takes place over a variable period of time and involves numerous sensory modalities. 

The function (effect) of the female parental attraction to the (any) infant schema is to mother-child affiliation what the function of male sexual attraction to the (any) nubile female is to adult male-female affiliation. Both kinds of attraction predispose one to interact with the individual who possesses the "object of attraction." As a result of this interaction, affiliation with a particular individual can occur. 

Coding and Storing Attributes on the Basis of Non-structurally Perceived and Processed Properties 

As discussed previously, some attributes that cannot be perceived on the basis of the attributes’ structure are coded and stored in the love map in ways that require processing at a higher level of neural integration.

Two such bases by which coding and storing occur have been identified:

(1) relative age and relative gender and

(2) function (to be discussed).

The first basis applies in both males and females, while the second basis applies in females only. Both bases will be discussed as they relate to human males and human females after a brief discussion of the concepts of relative age and relative gender and of function.

Relative age and relative gender are not coded and stored on the basis of their perceived structure, because the attribute is not the perceived age or gender structure per se but, rather, a comparison of the perceived age and gender structure of another individual with the perceived age and gender structure of self, which is mediated through Money’s (1986) concept of gender identity role (G-I/R).

A higher level of neural-integration processing determines that the other individual is

(a) either younger or older than self and

(b) either more masculine or more feminine than self
(see Figure 1.9).

This comparison results in four possibilities, which are seen in the four Attraction Quadrants of Figure 1.9.

(For simplicity, the choices are made binary and are limited to "older" and "younger than self." However "older" can be thought of as "same age or older,“ and "younger" can be thought of as "same age or younger." The same applies to "masculine" and "feminine.“)

The concept "gender," as it is used in this chapter, first must be defined from a biosocial point of view and in a meaningful way. An attribute is given a gender designation (masculine or feminine) if its distribution is skewed between the two sexes but it is not distributed exclusively in one sex or the other

Attributes that are distributed exclusively in one biological sex or the other are called "male" or "female" attributes rather than "masculine" or "feminine" attributes. For example, "small" is a feminine attribute because the average female is smaller than the average male. However, a penis is a male (not a masculine) attribute because only males have a penis. Attributes such as "large," "strong," and "hairy" are considered masculine attributes, and attributes such as "small," (physically) "weak," and "hairless" are considered feminine. 

The concept of gender, i.e., masculine and feminine, does not depend upon whether genetics ("is strong") or culture ("wears a dress") is responsible for the skewed distribution of the attribute between the two biological sexes. 

It is also important to appreciate that among humans, one is not initially sexually attracted to another individual’s biological sex, inasmuch as one would have to examine an individual’s chromosomes to know for certain whether the individual is a biological male (XY) or female (XX). In an initial encounter in clothed societies, one does not see genitals either, perceived structures that usually distinguish biological males from biological females. 

Rather, one is initially attracted to the individual’s perceived shape and movement, to the secondary sexual characteristics, and to the sexually dimorphic (i.e., masculine or feminine) clothing, hairstyle, and adornment. When the sum of the gender attributes is more masculine than feminine, one assumes the individual is a biological male; when the sum of the gender attributes is more feminine than masculine, one assumes the individual is a biological female. However, one male can be more masculine or more feminine than another male, and one female can be more masculine or more feminine than another female.

Function is another way not based upon perceived structure by which attributes are coded and stored in the love map. Functional attributes are explained as follows: The function of a behavior is determined by its effects. [*25] Functional attributes are not the perceived structure of behavior per se but, rather, are the consequences, or the effects, of behavior. The human female (but not the human male) love map, for reasons that will be explained, is composed of attributes that are coded and stored on the bases of function as well as relative age and relative gender. 

Human Males 

The love map of the human male, in addition to its attributes coded and stored on the basis of their perceived structure, also contains attributes coded and stored on the bases of relative age and relative gender. Relative age and relative gender are the bases on which the four Attraction Quadrants for human males in Figures 1.9 and 1.10 were developed. 

Human males are found in each of the four Attraction Quadrants, depending on their age and sexual orientations as well as their stage in the life span. 

(See the discussion relating to the Attraction Quadrants in the ensuing greater subsection, which is titled "Who’s Who in the Attraction Quadrants") 

Human Females 

In human females, attributes based on relative age and relative gender are coded and stored on a nonstructural basis in the love map throughout the life span. The Attraction Quadrants in which a female resides differ, as in males, throughout the life span and are dependent upon both age and sexual orientations. 

Attributes coded and stored on the basis of behavioral function, as a result of processing at higher levels of neural integration, also are in the love map of human females. Behaviors that result in functions, such as caring, provisioning, and protecting, would usually be highly desirable components of the female love map.

Such coding and storing in the human female love map of attributes on the basis of their function is most likely a counterstrategy that enables the human female to detect male deception and "false advertising" in the form of visual symbols of reproductive success. However, human males have evolved a counterstrategy to female functional-attribute assessment of them in the form of verbal tales of functional heroism. 

Who’s Who in the Attraction Quadrants 

Only males will be discussed, since the purpose of this subsection is to show the individual relationships between andro- and gynephilic pedo- and ephebophiles and (male) individuals with other age and sexual orientations throughout the life span. The following discussion refers to Figure 1.10

Quadrant A: Attraction to Individuals Older and More Feminine than Self

Adolescent heterosexual males’ sexuality awakens at puberty to structurally perceived attributes that are fully developed in nubile females who are considerably older and more feminine than self. In modem industrialized societies, sexually evocative adult female models in magazines and actresses in films, voyeurism, and fantasy are the closest means by which most young adolescent males can get to the structurally perceived, animate attributes in their love map in a sexual context. 

Adult male heterosexual masochists often stay in this quadrant throughout their life span. They become fixated on the dominant, fear-inducing role of the female individual in their love map more than on her perceived structural attributes. [*26] 

(In general, age correlates positively with dominance.) 

Quadrant B: Attraction to Individuals Younger and More Feminine than Self

Almost all adult heterosexual males eventually wind up in this quadrant after passing through a transient phase, starting at the end of their second decade of life, of maximum sexual attraction to individuals more feminine than and of the same age as self.

All (androphilic and gynephilic) pedo- and ephebophiles are in this quadrant throughout their life span. Male as well as female children and adolescents are always younger and more feminine than an adult male pedo- or ephebophile throughout his life span. 

Quadrant C: Attraction to Individuals Younger and More Masculine than Self

Almost all adult homosexual males are in this quadrant after having passed through a transient phase, starting at the end of their second decade of life, of maximal sexual attraction to individuals more masculine than and of the same age as self. It is for this reason that adult homosexual males, more so than adult heterosexual males, value (in themselves and others) the signs and symbols of male youthfulness and masculinity, such as a muscular body and facial hair. 

Adult homosexual males are not very attracted to the more feminine, smooth, hairless skin and lanky habitus of a pubescent male, which attract the androphilic ephebophile. Adult homosexual males have virtually no sexual attraction to the prepubertal habitus of a male child, which attracts the androphilic pedophile.

Quadrant D: Attraction to Individuals Older and More Masculine than Self

Homosexual males’ sexuality awakens at adolescence to structurally perceived attributes that are fully developed in males who are older and more masculine than self. In contrast to adolescent heterosexual males, however, adolescent homosexual males have more opportunities for confronting the structurally perceived, animate attributes of their love map in person rather than through magazines, films, voyeurism, and fantasy. 

Almost any older male, with perhaps the exception of an older transsexual male, would be more masculine than self, and there are numerous societally institutionalized opportunities afforded for culturally sanctioned all-male nudity. Adult male androphilic ephebophiles are the obvious individuals whose interests as well as attributes match the relative age and relative gender attractions of adolescent homosexual males. 

Adult male homosexual masochists often stay in this quadrant throughout their life span. They are fixated on the dominant, fear-inducing role of the individual in their love map more than on the individual’s structurally perceived attributes. [*27]

Most transsexual males are in this quadrant throughout their life span. The usual definition of a transsexual male is "a male individual whose G-I/R is so feminine that he subjectively feels like a biological female."

Proximate Mechanisms Underlying Specific Age and Sexual Orientations in Human Males: The Two-Dimensional Model


The data on the sexual differentiation of the male brain and the correlation of this differentiation with behavioral sex differences in childhood, adolescence, and adulthood are best understood using the two-dimensional "organizational" model of embryological hormonalization:

  1. 1. The process of masculinization and

  2. 2. The process of defeminization.
    (See Goy and McEwen, 1980; McEwen, 1987; Pillard and Weinrich, 1987).

This model is illustrated in Figure 1.11, overlaid on the already discussed Attraction Quadrants.

Figure 1.11

Relationship of brain masculinization and brain defeminization in the male to relative-age and relative-gender preferences in the four Attraction Quadrants. Compare to Figure 1.10 and see text. 

The North- and East-pointing arrows signify that the brains of male (and female) fetuses start out unmasculinized and feminized and that their degree of masculinization and defeminization is primarily responsible for the variance in gender-typical behavior and gender-typical sexual attraction both within and between the two biological sexes.

The two-dimensional "organizational" model of embryological hormonalization means that masculinization of the brain is not the same as defeminization. There is good corroborating, empirical evidence in the rate that masculinization and defeminization are mediated by temporally hormonally different, although related, processes

(Meaney et al., 1983; Hutchison and Hutchison, this volume).

However, it should not be assumed that the effects of defeminization and masculinization are completely independent processes in any species, especially in humans, in whom the concept of G-I/R is an important intervening variable (see Money, 1986).

The above-described organizing effects of sex hormones on the sexual differentiation of the brain during embryogenesis must be contrasted with the activating effects of the sex hormones on the development of secondary and tertiary (explained later) sexual characteristics of puberty.

For example, Goy and McEwen (1980, pp. 6-7) suggest that there are three basic types of "male-more-frequent" sexually dimorphic behaviors (tertiary sexual characteristics), which are mediated by three different proximate mechanisms:

Type I
Those behavioral characteristics that cannot be brought to full expression unless the relevant hormone(s) is (are) present in adequate amounts in the circulation during both the critical (organizational) period of early development and a later (activating) life stage.
Examples are

a. Male intromissive and ejaculatory behavior

b. Male fighting behavior (some species/strains)

Type II
Those behaviors that seemingly require only activation at later ages by appropriate hormones.
Examples are

a. Yawning behavior of rhesus monkeys 

b. he Mounting behavior (some species/strains)

Type III
Those behaviors that require only the organizational effects of androgens, in which no activational influence is required for their full expression. Examples are

a. Juvenile play and mounting behavior of rhesus monkeys

b. Urinary (micturational) patterns of dogs

The relationship of these three types of sexual behavior and their three underlying proximate mechanisms to andro- and gynephilic pedo- and ephebophilia is that the components and correlates of these age orientations in humans can eventually be subjected to a similar typology.

Sociopolitical Background

The editor of and the contributors to this volume are aware of the socially and politically sensitive topics about which they write. Numerous well-respected social scientists have objected to behavioral-physiology and -biochemistry, mechanistic research on sexual orientation, in that the research implies the presence of an "abnormality" in the medical sense. The same argument could apply to similar research on age orientation.

However, the search for mechanistic, physiological and biochemical correlates of behavioral variability concerning both age and gender attractions does not imply that the correlates or the individuals in whom the correlates are found are "medically abnormal."

Also, the relationship between adult male homosexuals and male androphilic pedo- and ephebophiles is both socially and politically very sensitive. Yet, empirical evidence suggests that age preference and gender (sex) preference are not completely independent variables. For example, 

the majority of adult human males are sexually attracted to individuals younger and more feminine than self; 

the majority of adult human females are sexually attracted to individuals older and more masculine than self.

Finally, there is a strong voice in the gay social science literature to keep separated conceptually and ideologically the concepts of 

gender-atypical behavior in self and 

gender-atypical attraction to others. 

Nevertheless, correlations between gender-atypical behavior and gender-atypical attraction exist (e.g., Green, 1987), and efforts to understand and characterize these correlations are appropriate endeavors of science.

The Two-Dimensional Mechanisms

It is well established that during embryogenesis, the internal reproductive organs, the external genitals, and the sexual differentiation of the brain will proceed along female-typical lines unless the embryo is masculinized and defeminized to a varying degree by pre- and peri-natal organizing hormones.

In the effort to understand some of the outward manifestations of brain defeminization in humans, it is helpful to use Birdwhistell’s concept of
"tertiary sexual characteristics" as being 

"sexual characteristics which are patterned social-behavioral in form" (Birdwhistell, 1979, p. 42). 

Such tertiary sexual characteristics are differentiated from the morphological, secondary sexual characteristics of puberty and from the primary sexual characteristics (male or female genitals) that are present at birth. In this subsection on proximate mechanisms, the female-more-frequent, feminine (often called "effeminate" when they occur in a biological male) behaviors to be discussed under "Defeminization" can be thought of as being tertiary sexual characteristics.

The processes of brain masculinization and defeminization will be discussed, especially in reference to their possible relationship to pedo- and ephebophilia. Brain masculinization is discussed first because it occurs first in both phylogeny and ontogeny. All male brains start out unmasculinized on the (horizontal) umnasculinized-masculinized axis and feminized on the (vertical) feminized-defeminized axis in Figure 1.11.


Masculinization, from a proximate, mechanistic perspective, is the association of social dominance and all that is connected with it 

(e.g., male-male competitive aggressivity; proceptive, searching, appetitive behavior; and mounting behavior [*28]) 

with sexuality. It is also the functional dissociation and distancing of fear from sexuality 

(see Medicus and Hopf, this volume).

Because the appetitive component of male-more-frequent proceptive sexual behavior involves more locomotor activity than does the female-more-frequent stationary, proceptive expressive display, masculinization of the brain appears to produce an overall increase in nonspecific motor behavior in the male in many different contexts. 

It is for this reason that even the average pre-pubertal nonhuman, as well as human, primate male is more active (and generally more aggressive) than the average pre-pubertal female. Interestingly, human female children whose brains have been organizationally masculinized in utero as a result of adreno-genital syndrome show the level of activity and the rough-and-tumble play that are characteristic of male children (Ehrhard, 1974). 

The predisposition of most males to associate social dominance (in themselves) with their own sexuality causes submissive attributes (in others) to become sexually alluring to them. Also, submissive displays by others inhibit aggressivity and allow courtship by self to proceed. As a result of these two factors, many adolescent and adult human females not only dress themselves so that they appear to be submissive and helpless but also behave more submissively and helplessly in the presence of males than in the presence of other females. Submissive attributes, such as "small," "weak," "young," and "helpless," are, of course, attributes of all (male and female) children and adolescents in comparison to adult males. In relation to children and adolescents, all males become more dominant as they move from puberty to adulthood. 

To understand the relationship of dominance to male sexuality, one must appreciate the nature of vertebrate social behavior, in which both dominance and submission are relative, relationship- and context-dependent roles in each sex and in each individual. 

The dual (dominant/submissive) potentiality of all individuals is best seen in human sadomasochism/bondage dominance (S&M/B&D), a paraphilia in which hierarchal (dominant/submissive) role relationships both predominate and facilitate sexual arousal. 

Comparing the distribution of the roles between the two sexes, the average adult human female’s sexual fantasies and behavior tend to be self-reported as submissive and associated with fear, whereas the average adult ma1e’s sexual fantasies and behavior, when compared to the average female’s, are self-reported to be more dominant and associated with aggressivity 

(see Eibl-Eibesfeldt, this volume; Medicus and Hopf, this volume). 

Comparing the distribution of role-related sexual behavior among males, one finds, although such studies are plagued by sampling biases, that self-reported heterosexual males may tend to prefer the dominant role somewhat more than do self-reported bisexual and homosexual males, although they are shown graphically as equally masculinized in Figure 1.10

All (androphilic and gynephilic) pedo- and ephebophiles, whose brains are extremely masculinized throughout their life span, are in very dominant roles in their sexual interactions with children and adolescents. Although it is not shown graphically in Figure 1.10, all pedophiles would be more masculinized than all ephebophiles. 

Transsexual males, whose brains are never masculinized in their life span (i.e., they remain unmasculinized), are most often sexually attracted to power and dominance in very masculinized, older-than-self, heterosexual males. ,

The same masculine dominance sexuality whose reptilian origins make submissive attributes sexually alluring in a potential mate can also engender feelings of nurturance and care giving towards individuals with these attributes, partly because of the phylogenetic origins of this response from mammalian parent/offspring relations (see Eibl-Eibesfeldt, this volume). However, dominance sexuality can also be associated with sadism towards a sexual partner, which almost certainly is redirected, functionally proximate aggression that evolved in the service of intraspecific, male/male sexual competition.

However, as previously discussed in the section of this chapter titled "The Lovemap," compared to the structurally perceived, coded, and stored attributes of shape and movement of the proceptive nubile female (Figure 1.7a), the attributes of submissiveness are not coded and stored on the basis of perceived structure, in that they first are processed (to determine relative social rank) at higher levels of neural integration.

Therefore, submissiveness per se cannot serve very well as an unconditioned stimulus through which a previously neutral stimulus is transformed into sexually evocative status. For example, the sight of relative smallness per se — all other attributes, including relative age and relative gender, being randomized — itself would not be associated with male sexual arousal.

Because of this relative unconditionability of submissive- (and dominant-) role-related sexual behavior per se, adult male humans who are aroused by dominant- or submissive-role relationships have undergone the conditioning of their sexual arousal to specific paraphernalia (e.g., black leather), which gets paired with and conditioned directly to the sexual arousal associated with their use. Black leather is no more intrinsically dominant or submissive today than lace is intrinsically feminine.


The defeminization of a male is the process by which the male comes to exhibit less female-more-frequent, proceptive and mount-receiving behavior. Much female-more-frequent behavior, if not inhibited by the defeminizing effects of androgens and their metabolites, appears to be mediated by the female sex hormone estrogon and to be facilitated by the female sex hormone progesteron.

In an exquisite example of inductive neurobiology, Pfaff (1980) has shown the relationship of estrogen and progesterone to the most feminine of all rodent behaviors, lordosis, which is the arching of the back and the rotating of the pelvis dorsally (towards the buttocks), a signal of mounting-behavior receptivity and a facilitation of ventral/dorsal (conceptive phase) mating.

Although humans have risen from quadrupedalism to bipedalism (i.e., walking on two rather than four limbs) and are capable, along with bonobos (pygmy chimpanzees), of ventral-ventral mating, evolution is conservative.

As a result, female lordosis remains a pre-adapted visual releasing stimulus to the heterosexual human male that is part of the proceptive,  expresive-behavior repertoire of human females. Lordosis is very evident  in sexually evocative "pin-up" photographs of human females, in the sexual selection  for steatopygia (fat deposits on the buttocks) in Hottentot females, and in the "bustle dress" worn in the late 19th and early 20th centuries by urbanized Western adult females.

(See exaggerated lordosis in nubile female  releasing stimuli in figure 1.7a)

Because of human bipedalism and the freeing of the upper extremities, which came to be used in communication, among other activities, there are a variety of other female-more-frequent, proceptive, expressive behavioral motor patterns of both the upper and lower extremities that are attributable to a relative lack of brain defeminozation.

The proximate segments of both the upper and lower extremities (i.e., forearms and thighs) are carried closer to the midline of the body by females than by males, resulting in a relatively smaller stride in females. In contrast, in females more so than in males, during sexually evocative displays there is more loose-jointed flexion and extension in the more distal segments of both the upper (wrists and fingers) and the lower (ankles) extremities.

There also are numerous female-more-frequent, pre-adapted, proceptive, expressive facial and eye behavioral motor patterns, such as tongue thrusting, lip pursing, vertical eye rolling, and increased social. smiling and eyebrow flashing. In addition, there are female-more-frequent whole-body movements, social behaviors, and the expressive-behavior component of speech.

Since (a) remaining brain feminized (not being brain defeminized) results in the execution of structurally codable and storable, female-more- frequent, proceptive, expressive behavioral motor patterns in heterosexual females  and

since (b) brain-defeminized heterosexual males are characterized by a relative lack of such behavioral motor patterns in themselves and (visual) attraction to such behavioral motor patterns in others,

then (c) brain defeminization is organizationally associated with the male-more-frequent visual-structural-perceptual configuration of the stimulus filter of the love map.

That is, the female-more-frequent pattern is the execution of these proceptive expressive behavioral motor patterns, and the male-more-frequent pattern is the proceptive visual search for both the behavior and the individuals exhibiting it.

Defeminization, which organizationally inhibits the expression of female-more-frequent, proceptive expressive behavior as well as biasing the stimulus filter toward visual-structural-perceptual configuration, will now be discussed along with the organizational effects of masculinization in males with differing age and sexual orientations in order that pedo- and ephebophilic males can be seen in perspective.

The Age and Sexual Orientations [*29]


Brain masculinization makes submissive-like diminutive size sexually alluring. Another effect of brain masculinization — which is associated with aggressive, male-male sexual competitiveness over access to nubile females or is replaced by sublimated, less physically violent behaviors in industrialized societies — is resource competition in the marketplace. Adult heterosexual males also still actively search and exclusively show mounting (insertion) behavior.

As a result of brain defeminization, the marked degree to which visual, structurally perceived, coded, and stored attributes compose the love map in self-reported heterosexual males also leads to the subsequent, easily conditioned eroticization of an array of animate, inanimate, and contextual, visual, structurally perceived, codable and storable objects.

Remember that stimulus potency increases with the degree of stimulus discrimination in individuals who have a high capacity to discriminate stimuli once the phylogenetically familiar stimulus has been found

(see top and then right half of the bell-shaped curve in Figure 1.5).

Therefore, in heterosexual human males, visual eroticism causes stimulus appetence toward the (any) phylogenetically familiar, nubile female shape, the accompanying feminine proceptive, expressive behavior, and the idiosyncratically conditioned, ontogenetically made-familiar, accompanying visual-structural appurtenances such as lace. Most self-reported heterosexual males exhibit relatively little female-more-frequent, proceptive expressive behavior. The variance in the expression of this behavior probably is accounted for by variance in the degree of male-brain defeminization and by the self-report method of defining this population.

Pedo- and Ephebophilia

Brain masculinization is mainly responsible for the very strong eroticization of diminutive, submissive-like attributes characteristic of children and adolescents and forms the major proximate basis for pedophilia and ephebophilia. Although it is not shown graphically in Figure 1.10, pedophiles are more masculinized than ephebophiles.

Male-male competitive aggressivity is reflected best in socio-economic status in stratified societies, but sufficient data to support or refute testable hypotheses relating to the socio-economic status of pedo- and ephebophiles have not been collected. Searching proceptive behaviors are very evident, but mounting behavior (insertion) is conspicuous by its relative absence with children but by its presence with adolescents.

The defeminized coding and storing of the love map on the basis of perceived structure may account, although to a slightly lesser degree than in heterosexual males (see Figures 1.10 and 1.11), for some aspects of pedo- and ephebophiles’ visual-structural-perceptual attraction to the infant/child schema as well as their attraction to the visual-structural- perceptual aspects of specific stages of nascent or budding secondary sexual characteristics or attributes. Within pedo- and ephebophiles, androphilic individuals are less defeminized than gynephilic individuals (see Figure 1.10).

If the ease of visual sexual conditioning is a function of the degree of brain defeminization, then pedo- and ephebophiles should be slightly less prone to visual conditioned sexual arousal than heterosexual males, with androphilic pedo- and ephebophiles less prone than gynephilic pedo- and ephebophiles.

The relatively high degree of brain defeminization in all pedo- and ephebophiles is also evident in the relative lack of female-more-frequent proceptive expressive behaviors in this population as compared to homosexual and transsexual males.

Freund et al. (1989) present the following unsolved paradox regarding the ratio of gynephilic to androphilic pedo- and ephebophilic males, for which there is now a new biosocial explanation using the two-dimensional model of differential masculinization and defeminization of the brain.

The ratio of female to male children and adolescents reported to have been sexually involved with adults is approximately 2 : 1, whereas the ratio of heterosexual to homosexual adult males, who are attracted to adults, is approximately 20 : 1.

Yet, self-reported and plethysmograph-verified adult homosexual males are no more sexually aroused plethysmographically by male children and adolescents than adult heterosexual males are sexually aroused plethysmographically by female children and adolescents.

Freund et al. conclude, therefore, that androphilic pedo- and ephebophilia are more closely linked to homosexuality than to heterosexuality, a conclusion that will be contested by the alternative, two-dimensional biosocial model.

(Freund et al.’s terminology was made compatible with this volume.)

There are two other compatible-with-each-other explanations of this paradox not mentioned by Freund et al.:

(1) Abel et al.’s data in the recent literature and

(2) the biosocial, two-dimensional model developed in this chapter:

(1) Abel et al.’s (1987) study of self-reported sex crimes of non-incarcerated paraphiliacs found that

although the ratio of gynephilic pedo- and ephebophiles to androphilic pedo- and ephebophiles was approximately 1.5 : 1.0,

the ratio of the mean number of paraphilic acts per gynephilic pedo- or ephebophile to androphilic pedo- or ephebophile was approximately 1.0 : 10.0.

The ratio of completed  acts per female child or adolescent : male child or adolescent was approximately 1.0 : 1.5, and

the ratio of female children and adolescents to male children and adolescents who are sexually involved with an adult male is calculated to be approximately 1 : 5.

Therefore, estimating the ratio of gynephilic to androphilic pedo- and ephebophiles from the ratio of female to male children who are sexually involved with adults is a sampling error that overestimates the ratio of androphilic  to gynephilic pedo- and ephebophiles and explains the paradox.

(2) The biosocial model herein developed assumes that the central tendency in evolution is to produce heterosexual males by producing an optimal amount of masculinization and defeminization of the male brain in utero.

As a first-order approximation, if the points in Figure 1.10 are thought of as representing rectangular cartesian coordinates originating where the two axes bisect, both an X- and a Y-axis normal distribution can be imagined in which the point that represents adult heterosexual males would be in the center of the normal distributions on both the X- and the Y-axes.

The distance on the Y-axis between adult heterosexual males and gynephilic pedo- and ephebophiles is slightly less than the distance between adult heterosexual males and androphilic pedo- and ephebophiles.

Therefore, based on an overlying normal distribution on the Y-axis around heterosexual males, the model correctly predicts that there should be slightly more gynephilic than androphilic pedo- and ephebophilic males in the general population.

Again, based on how the points are distributed in the model, the distance between adult heterosexual males and adult homosexual males is significantly less on both the X- and the Y-axes than the distance on these same two axes between adult heterosexual males and transsexual males.

If these distances on the X- and the Y-axes reflect frequencies in overlying normal distributions, they correctly predict that there would be several orders of magnitude difference between the population frequencies of adult homosexual and transsexual males.

In contrast to Freund et al.’s interpretation of their data that pedo- and ephebophilia are more closely linked with male homosexuality than with male heterosexuality, the model developed herein comes to exactly the opposite conclusion: All (andro- and gynephilic) adult male pedo- and ephebophiles should be more closely linked to adult male heterosexuals than to adult male homosexuals.

Therefore, adult females would (counter-intuitively) be predicted to be sexually preferred over adult males by the majority of both andro- and gynephilic pedo- and ephebophiles.

Likewise, based on how the points are distributed in the model and assuming two normal distributions around heterosexuality, androphilic pedo- and ephebophilic males are (counter-intuitively) predicted to be more common in the general population than homosexual males.

Since androphilic pedo- and ephebophilic males are so close to adult heterosexual males in the model, it is suggested that such pedo- and ephebophilic males can facultatively adapt to whatever behavior is culturally accepted.

If the distribution of the points in the model reflects differing degrees of masculinization and defeminization of the male brain, then there is every reason to believe that the distributions would actually be continuous across all males rather than being discontinuous around arbitrary and non-mutually exclusive categories such as "heterosexual" and "androphilic ephebophile."

Remember that both heterosexual males and androphilic ephebophiles are capable of being sexually attracted to individuals who are younger and more feminine than themselves, since they both reside very near each other in Quadrant B in Figures 1.9, 1.10, and 1.11.

In certain historical times, such as ancient Greece, males in the lower half of Quadrant B openly interacted sexually with both adult females and adolescent males. In most modern industrialized societies, the majority of such males most likely live out their adult lives as married or single heterosexual males. The ones that do not often come to the attention of the types of professional individuals who would be interested in this volume.


Brain masculinization should produce eroticization of diminutive attributes, but because of a concomitant lack of defeminization (see Figure 1.10), this potential is not realized in attributes stored on the basis of their perceived structure as much as it is in heterosexual males.

As a result, brain masculinization is realized most in appetitive searching ("cruising") behavior. Male-male resource-competitive aggressiveness is not under cultural selection pressures from heterosexual females, and as a result, in industrialized societies, homosexual males are drawn towards the human services more than towards highly resource-competitive fields (Feierman, in press). Both brain-masculinization-produced mounting behavior (insertion) and brain-un-defeminized mount-receiving behavior (recipient of insertion) are common.

Compared to adult male heterosexuals and all pedo- and ephebophiles, adult male homosexuals are more commonly un-defeminized 

(see Figures 1.10 and 1.11),

 especially in childhood and adolescence

(Green, 1987; Saghir and Robins, 1973).

In adulthood, there is much more variance in the degree of phenotypic defeminization among self-reported homosexual males, with some individuals behaving as if they were very defeminized; this variance probably is secondary to variance in both the degree of defeminization and social learning.

The relatively un-defeminized homosexual male, compared to heterosexual and (androphilic and gynephilic) pedo- and ephebophilic males, as previously stated, is relatively less dependent on visual-structure coding and storing of the love map, and in such a male, therefore, the conditioning of previously neutral stimuli to the intrinsic and primary structure of sexual gratification, the penis, occurs less easily

(see Figures 1.10 and 1.11).


A relative lack of brain masculinization and a lack of cultural selection from heterosexual females would be predicted to produce virtually no male-male resource-competitive aggressivity in the marketplace. Instead, similarly to heterosexual females, who would reside in the same Quadrant D, there would be more of a relationship between fear and sexuality

(see Medicus and Hopf, this volume).

This relationship is often not realized because of the low sex drive of many transsexuals. Searching appetitive behavior would be predicted to be virtually absent. Low brain de-feminization accompanied by low brain masculinization would make mount-receiving behavior exclusive over mounting behavior.

Transsexual males are usually defined on the basis of G-I/R. However, a definition of a biological male who is sexually attracted to other individuals who are older and more masculine than self throughout the life span will very nearly capture the same individuals who have been defined as transsexual males on the basis of G-I/R. Transsexual males are the least brain-defeminized males 

(see Figures 1.10 and 1.11).

As a result of very low brain defeminization, they also are less sexually attracted to the penis (theirs and others’) than are non-transsexual homosexual males, because the penis is very much a perceived structure and a male structure at that. This relatively diminished attraction is perhaps why they are often able to sacrifice their penis (and testicles) to the surgeon’s scalpel.

It is predicted that in male transsexuals, there would be few if any visual secondary stimuli conditioned to sexually evocative status (i.e., they would have few animate, inanimate, or contextual fetishes). Their attraction to feminine clothes is an attraction to the feminine G-I/R and is not associated with sexual arousal, which would be the case in an animate fetish.

Transsexual males, being the least brain-defeminized of all males, would be expected to exhibit the greatest number of female-more-frequent, proceptive expressive behaviors and to exhibit them to the greatest degree. Indeed, this prediction is borne out. Transsexual males often exhibit more of these behaviors, in an exaggerated way, than adult females do.


Both androphilic and gynephilic adult male pedo- and ephebophiles spend their entire life span in Quadrant B of Figure 1.11, where their brains are

(a) slightly less defeminized and slightly more masculinized than occurs in adult heterosexual males,

(b) much more defeminized and more masculinized than occurs in adult homosexual males, and

(c) markedly more defeminized and markedly more masculinized than occurs in adult transsexual males (compare Figures 1.10 to 1.11).

Comfort (1987, p. 8) comes close to the conclusions that are presented in this chapter when he states,

"Paedophilia . . . may be a [visual] imprinting disorder aggravated by low dominance."

The imprinting seems to be to the visually perceived structural properties of the highly discriminable, developing secondary sexual characteristics of children or adolescents

(see D’Udine, this volume).

However, instead of "aggravated by low dominance," this chapter suggests, they are "sexually" aroused by the attributes of high (extreme) /diminutive submission."

Remember that Figures 1.9, 1.10 and 1.11 refer to sexual attraction to relative, not absolute, social status. Many pedo- and ephebophiles are of very high social status, but so are their same-age peers

(Brongersma, 1986; Silva, this volume).

Adult-Child and Adult-Adolescent Sexual Behavior Versus Sexual Abuse

To understand the relationship of adult human sexual behavior with children and adolescents tot sexual abuse of children and adolescents requires a more thoughtful consideration of the concept "sexual abuse". The two aspects of sexual abuse that appear to be paramount will be considered: consent and harm.


Consent certainly precludes any behavior that is physically "forced" on an individual or done to or with an individual without "explicit authorization." Sexual behavior without consent is one form of sexual abuse.

However, consent is extremely difficult to determine while behavior is occurring and almost impossible to determine retrospectively, except where brute force or weapons are used, which is unusual in adult-child and adult-adolescent sexual behavior. Also, in most jurisdictions, there is an age, usually 12 and under, during which children are not even considered to be capable of giving consent. [*30]

The reason consent is so difficult to determine is that consent-containing messages are transmitted simultaneously by both verbal and nonverbal means with the nonverbal messages often containing different and sometimes conflicting information. Also, certain proceptive expressive behaviors that are frequently used in courtship, such as coyness, are assumed by many individuals to be displayed. with the conscious, ontogenetic intention of sending a flirtatious message of consent. Yet, individuals who behave in a coy manner may verbally self-report that they consciously did not intend to send this message. Their self-reported statement may be true in that intent can be embedded in phylogeny as well as in ontogeny.

With children and adolescents, as well as with adults, it is always possible that there is ontogenetic intent — but that the intent pertains to affiliative behavior that is not necessarily of the kind that leads to sexual behavior. Sexual affiliative displays in the form of proceptive expressive behavior usually are distinctly recognizable by their context and consequences (Moore, 1985), but they often are preceded by nonspecific, nonsexual affiliative displays, such as social smiling.

Sexual seduction means "the subtle (verbal or nonverbal) coercion, versus outright (verbal or nonverbal) propositioning, of one individual into sexual behavior by another individual."

Seduction must be viewed within the context in which it is occurring. The seduction of a child or an adolescent by an adult is an extreme asymmetry of power, skills, ability, and knowledge and is the reason why any adult-child and adult-adolescent sexual behavior is suspect of being sexual abuse.

The age of peak total sexual outlet (orgasms/period of time) is considerably younger for human males than it is for human females (Kinsey et al., 1948, 1953). Peak total sexual outlet occurs during late adolescence and early adulthood in males, and as a result, adolescence is a time of very high male sexual drive.

In many societies, adolescent males, more so than adolescent females, have great difficulty in finding opposite-sex sexual partners of any age, which is one reason why adolescence is often an age of male (and, to a lesser degree, female) homosexual behavior. [*31]

As a result of this difficulty and for other reasons, seduction by an adult male ephebophile is considerably easier when the adolescent is male rather than female.


Harm is the second criterion that would make adult human sexual behavior with children and adolescents qualify as being sexual abuse. In the subsection "Inclusive Fitness and Kin Selection," which was presented earlier in this chapter in the section "Adult-Child and Adult-Adolescent Sexual Behavior Within the Context of Reproductive Behavior," there were five hypotheses proposed for discussion and testing:

  1. Adult-child and adult-adolescent sexual behavior derive from biological determinants that are or were adaptive, having evolved by kin selection because they increased inclusive fitness.

  2. Adult-child and adult-adolescent sexual behavior derive from biological determinants that are products of random, non-selected genetic mutations.

  3. Adult-child and adult-adolescent sexual behavior derive from biological determinants that have been produced by non-selected genetic drift as human populations migrated geographically.

  4. Adult-child and adult-adolescent sexual behavior derive from biological determinants that are a by-product of selection for other traits, such as heterosexuality, within human populations.

  5. Adult-child and adult-adolescent sexual behavior are psychopathological, maladaptive responses to mental derangement or social dysregulation and actually lower the fitness (i.e., are harmful) to both of the interactants.

This subsection on harm addresses the fifth hypothesis.

Harm, on a short-term basis, can be considered from numerous perspectives. However, so little is known about the norms of typical child and adolescent sexual development in humans that deviations from typical development can hardly be defined.

From a purely biological perspective, harm of various types can be condensed into a common concept of "cost" as compared to "benefit." Numerous theoretical biologists use cost : benefit ratios as mathematical predictors of whether a trait should or could evolve by natural, sexual, and kin selection. The currency with which cost and benefit are measured is lifetime fitness.

Yet, measures of fitness are very different from the usual measures of outcome in the social sciences. In addition, most published reports on any long-term consequences of adult-child and adult-adolescent sexual behavior, using any outcome measures, are methodologically weak (Kilpatrick, 1987).

Harm will be examined in regard to female and male, child and adolescent, and heterosexual and homosexual sexual relationships with adults. Homosexual sexual relationships between adult females and female children and adolescents are not included because of a lack of sufficient published data.

Harm to the adult male is very society dependent, with the same behavior being normative in one society and punishable by long prison sentences in another society. Certainly, public humiliation and incarceration are harmful to anyone’s fitness.

To Female Children and Adolescents from Heterosexual Relations with Adults

As was previously stated, human females appear to have two reproductive strategies by which they transmit their genes to the next generation:

(a) reproduce at a young age, thus taking advantage of the mating appeal of their youth and the support of their extended family, i.e., maximizing mating effort;

(b) delay their own reproduction and improve their own spousal appeal, usually through their own education, i.e., maximizing parental investment.

In a female adolescent pursuing the second strategy, sexual behavior with males of any age, or even a reputation of sexual promiscuity, during adolescence will have a measurable cost to fitness.

Adult males can give adolescent females sexually transmitted diseases, some of which are a threat to future pregnancies and life. Adult males also can injure female children and adolescents by forcibly attempting intercourse with them. Sexual violence and sexual brutality themselves, however, are a separate issue from adult human sexual behavior with children and adolescents, which is not associated with sexual violence and brutality any more than is adult-adult sexual behavior.

Another type of harm that can be experienced by female adolescents who are involved sexually with adult males is the harm associated with prostitution. Some adolescent females do engage in prostitution with adult males, and most adult female prostitutes started prostitution during their adolescence. Adolescent prostitution provides a very-short-term economic gain and invariably will be shown to correlate with harm in terms of decreased lifetime fitness.

To Male Children and Adolescents from Heterosexual Relations with Adults

If harm is measured simply on the basis of cost to fitness, this author can think of no harm that would result in a non-coercive sexual interaction between an adolescent male and an adult female as long as the adolescent male did not acquire a sexually transmitted disease.

Sexual interactions between adolescent males and adult females are common both in human and nonhuman primates

(Anderson and Bielert, this volume; Diamond, this volume).

From a purely bio-energetics perspective, there is very little cost to the adolescent male. However, the adolescent male could potentially deplete family resources if he, or his family, were made to provision an out-of-wedlock child from an adult female.

To Male Children and Adolescents from Homosexual Relations with Adults

Short-Term Effects

A sexual relationship between a male child or an adolescent and a male androphilic pedo- or ephebophile could have various outcomes. It currently is impossible, because of the lack of systematic follow-up data, to evaluate the probability of harmfulness or lack of harmfulness in a specific individual relationship. Some of the variance must relate to the age and sexual orientations of the child or adolescent and to the nature of the relationship.

There are numerous studies that report neutral or uneventful, nonfitness-related, short-term consequences in an almost testimonial manner. There also is much self-reporting of nonfitness-related harm, but the interpretation of this type of data is problematic, since it almost always is associated with other clinical psychopathology or criminal prosecution or civil lawsuits. There are, of course, contemporary human societies in the world in which this type of behavior is normative (Schiefenhovel, this volume).

Other studies have pointed out that there are adolescent males who are involved in sexual relationships with adult males who self-report that these relationships are positive experiences for them. There also are adolescent males who engage in sexual behavior with male androphilic ephebophiles for purely short-term economic gain. In terms of short-term effects on fitness, with the exception of the very real possibility of acquiring a sexually transmitted disease, the (biological) effect would have to be considered negligible, inasmuch as in adolescent males, sperm is an almost inexhaustible and easily renewable resource.

Long-Term Effects 

The long-term correlates of adolescent male homosexual prostitution with lifetime fitness are unknown, and when they become known, they probably will not progress beyond the simple correlation stage. As with adolescent female prostitution, short-term economic gain, rather than lifetime fitness, appears to be the proximate motivating factor. 

There is a myth perpetuated in the clinical literature that a sexual involvement during childhood or adolescence with an adult male will make a male child or adolescent seek out male children and adolescents for sexual gratification when that male child or adolescent becomes an adult male himself. The evidence for this so-called "abused/abuser hypothesis" has been critically reviewed by Garland and Dougher (this volume) and can best be summarized by the statement that such an experience is neither a necessary nor a sufficient cause of future adult sexual behavior with children and adolescents. 

Money (this volume) suggests that double-binded entrapment in an unpleasant sexual relationship, rather than adult-child or adult-adolescent sexual behavior per se, is the important variable. From a purely biological perspective, even if sexual experience with an adult male in childhood or adolescence were a necessary and a sufficient cause, it would not necessarily mean that an adult male with this kind of erotic orientation would be less reproductively fit than an adult male without such an orientation. It could easily be argued that such a male would want and father more children than an adult male who was not so attracted. The final answer to this question is not known, but the question itself is of immense practical and clinical significance and awaits future empirical research. 

Harm has been considered from a purely biological perspective, and this perspective does not consider the short- and long-term human suffering and misery to the child or adolescent and his family that can potentially result from many sexual relationships between adult males and male children and adolescents in contemporary societies. 

To be complete, however, one also must consider the suffering and misery to the adult male who is discovered to be sexually involved in any such relationship. In most industrialized societies, such behavior is criminal and is severely punished by public humiliation and long prison sentences. 

It also must be said that many adult males who are involved in such relationships self-report that they did not intend any harm to the male child or adolescent and that what they thought they were giving was love. (See Brongersma, 1986; Silva, this volume.) 

To Male and Female Children and Adolescents from Heterosexual and Homosexual Relations with Adults 

In addition to the specific kinds of harm that have been discussed, other kinds of harm to male and female children and adolescents have been attributed in the professional literature to adult human heterosexual and homosexual behavior with young individuals. Like some of the others, these kinds of harm, also, are long term: for example, increased susceptibility to such conditions as 

chronic pelvic pain in females, 


juvenile delinquency, 

drug abuse, 

criminal behavior, 

running away in adolescent males, 

memory problems, 


impulsive and self-injurious behaviors, 


personality disorders, 

characterological disorders, and even 

schizophrenia and 

other chronic psychoses. 

Other studies find about the same rate of psychiatric disorders in women who were sexually involved with adult males when they were children as would be expected of psychiatric-prevalence rates in the general community. The effects of these symptoms and disorders on lifetime fitness are largely unknown. 

Because of the natural design by which the data concerning humans are collected (i.e., no random assignment), the relationship between "childhood sexual abuse" and a myriad of adult conditions and situations may never be shown to be more than a simple correlation. 

When two conditions, such as A and B, are simply correlated (e.g., A—borderline personality disorder and B—self-report of a history of childhood "sexual abuse"), there are four hypotheses that can be entertained: 

  1. The correlation is spurious, 

  2. A causes B, 

  3. B causes A, and 

  4. Some unknown factor causes both A and B. 

Apart from specific disorders of sexual functioning, the common element that is found in the life histories of persons with many of the previously described conditions is overwhelming abuse: physical, sexual, or emotional. Sexual abuse seems equipotent to, or even less potent than, physical and emotional abuse. 

How to understand what makes certain types of adult-child and adult-adolescent sexual behavior abusive and other types uneventful and inconsequential is the major task awaiting other behavioral scientists who will study adult human sexual behavior with children and adolescents in the future. 


Pedo- and ephebophilia have been discussed in the context of a paraphilia, a socially unacceptable sexual attraction that now is partially understandable within a biosocial perspective through the overview provided in this introductory chapter and the more focused material presented by the other contributors in this volume.

There are three features that make pedo- and ephebophilia relatively common paraphilias [*32]: 

(a) the phylogenetically familiar nature of the stimuli in children and adolescents, 

(b) the propensity of children and adolescents to be sexually alluring to some males because of their diminutive size, and 

(c) the highly discriminable appearance of rapidly changing, budding secondary sexual characteristics. 

The theoretical curves in Figures 1.3, 1.5, and 1.6 and the placement of pedo- and ephebophiles in Attraction Quadrant B in Figures 1.10 are all first-order approximations made to fit the available data, much of which is preliminary. 

The following statements are qualifications that pertain to what already has been said; there is some benefit to grouping the qualifications together at the end of the chapter so that the issues they raise can be kept in mind as one reads the rest of this volume. 

  1. All published studies of pedo- and ephebophilia are the products of sampling biases. There is no way of knowing the true prevalence of sexual attraction to children and adolescents among adult males in the general population. Studies of incarcerated pedo- and ephebophiles may say more about the characteristics of individuals who have poor self-control of their impulses or who cannot negotiate their way out of the prison system than they say about pedo- or ephebophilia. 

  2. Pedo- and ephebophilia are emotionally charged issues, and as a result, even the most objective of scientific researchers are affected at least by the public’s reaction to the subject, if not by their own. There are advocacy groups at both ends of the spectrum (stricter laws versus decriminalization) who often use the forum of the scientific literature to covertly argue their own issue. 

  3. Pedo- and ephebophilia may be quite different phenomena etiologically and may resemble each other only to a degree. In future studies that look for biosocial or demographic correlates, the two should be kept separate. It is also important that the distinction between pedo- and ephebophilia stay rooted in biosocial criteria, such as the onset of puberty, rather than in legalistic criteria, such as a given chronological age. 

  4. Androphilic and gynephilic pedo- and ephebophilia may be quite different phenomena and, also, should be addressed as separate concepts in future empirical research. 

  5. The differences between "normal" hetero- and homosexual males and gynephilic and androphilic male ephebophiles may be subtle. As a result, ephebophiles will always be a more difficult group to study than pedophiles. 

  6. Pedo- and ephebophilia are quite different from pedo- and ephebo-sexual behavior, conceptually. Despite this difference, the two often are difficult to separate in practice. As a result, pure groups will be difficult to study. 

  7. Adult females occasionally are involved in sexual behavior with children and adolescents; adolescents of both sexes also can be involved in sexual behavior with children. Since the known central tendency in human populations is toward the sexual behavior of adult males with children and adolescents, it is correct that the major effort should first be in understanding this group. However, the full understanding of the behavior will not be completed until adult women and adolescents of both sexes, too, are understood conceptually. 

  8. Proximate mechanisms must be sought within the disciplines of developmental sexology, developmental neurobiology, neuro-ethology, and psycho-neuro endocrinology. 

  9. Compared to data that are available on the childhood development of heterosexual, homosexual, and transsexual males, there is almost nothing known of the childhood development of male androphilic or gynephilic pedo- and ephebophiles. This gap in knowledge must be filled if understanding is to proceed. 

  10. Pedo- and ephebophilia will be fully understood only with the addition of history, anthropology, and biology to the very fine work that already has been done in psychology and sociology. No one discipline has the complete answer to this issue, and the complete picture will require a large amount of interdisciplinary collaboration. 


The biosocial basis of adult human sexual behavior with children and adolescents was related to culture, behavior, motivation, mood, sexual interactants, sexual attraction, and sexual arousal. The concept of the love map was related to stimulus discrimination and to stimulus fitness and potency. The relationship of the love map to love and to two components of reproductive behavior, i.e., mating effort and parental investment, was discussed. 

The context in which reproductive behavior, i.e., its mating-effort and parental-investment components, occurs was used to provide an understanding of aspects of non-sexual reproductive behavior as well as non-procreative sexual behavior. 

The relationship of pedophiles and ephebophiles to individuals with other erotic orientations was shown. The relationship of adult-child and adult-adolescent sexual behavior versus abuse was covered using the concepts of consent and harm.

Speculations were offered as to some possible proximate mechanisms involved in the development of pedo- and ephebophilia using the concepts developed earlier in the chapter. General conclusions were given regarding the need for conceptual and methodological caution as well as clarity in future research in this field.