Keyword: Early sexuality of boys

Kinsey, Alfred; Sexual Behavior in the Human Male (1948) - chapter 5 - Early Sexual Growth and Activity; 35 pp, 157 - 192
Chapter five, here presented as a .PDF file, is devoted to early sexual growth and activity and first sets out to define erotic arousal and orgasm, noting the variation in pattern of orgastic response in individuals.
One significant finding was that more than 99% of these boys adopted a regular routine of sexual activity after the initial experience of ejaculation.