25 June 2017

Dear Dr. James: Could a certain amount of pedophilic interest simply be normal for men?

This question was left as an anonymous comment for last week’s entry, Will there ever be a cure for pedophilia?  But because I receive this question so frequently, thought I'd put it here as it’s own entry...
Dear Dr. James: Could a certain amount of pedophilic interest simply be normal for men? 
Men in prehistoric times who chased after say 9 year old girls would have left behind more descendants than men who chased after 30 year old women for the simple reason that a 9 year old has many more fertile years remaining. When men in primitive societies raid and abduct females from other tribes the most highly prized are the young virgin teens and preteens for the same reason. Essentially what's happening is that men are stealing eggs off other tribes and the females with the most eggs in their ovaries are the young virgins who haven't started reproducing yet.
That comment really has two parts. The first part is a straight-forward question with a straight-forward answer: Yes, typical men do indeed show a certain (very small) amount of response to children—this has been shown repeatedly again in the lab (Blanchard et al., 2009, figures shown below). That pattern of arousal does not indicate being a pedophile, however. Although typical men sometimes respond (a bit) to children, they respond more to older persons, and the most (by far) to adults. That is, typical men strongly prefer adults over children, even if some have some non-zero level of response to children.

The second part is an idea I have heard before, but I am afraid it is based on some false information: Fertility does not start at the beginning of puberty. Indeed, fertility does not start even when menstruation starts (another common misconception). The menstrual cycle begins at an average age of 12.3 to 12.9 (Euling et al., 2008; Finer & Philbin, 2014; Herman-Giddens et al., 1997), whereas a woman’s ovaries don’t start releasing eggs until roughly three years later, on average (Apter, 1980; Metcalf et al., 1983). Although we do occasionally see instances in the media of very young girls becoming pregnant, these are, of course, the exception. Hormone studies show that human fertility starts at the low point of puberty, increasing to peak during the 20s, and decreasing again over the 30s (Ellison, Panter-Brick, Lipson, & O’Rourke, 1993).

That is, a man who focuses his energies on women in their 20s would produce pregnancies than a man who focused those energies on women in their 30s (who are less fertile) or in their teens (and are least fertile of all).

Also arguing against the “kidnap them as girls to get all their subsequent offspring” idea is that it forgets that pedophilia is the preference for children. When such girls become adults and able to bear children, they are no longer attractive to the pedophile. Even though the now-adult could conceive children, the pedophile is more attracted to the girls who cannot. So, once again, the greater the pedophilia, the lesser the chance of successful reproduction.


Apter, D. (1980). Serum steroids and pituitary hormones in female puberty: A partly longitudinal study. Clinical Endocrinology, 12, 107–120.

Blanchard, R., Lykins, A. D., Wherrett, D., Kuban, M. E., Cantor, J. M., Blak, T., . . . Klassen, P. E. (2009). Pedophilia, hebephilia, and the DSM-V. Archives of Sexual Behavior, 38, 335–350.

Ellison, P. T., Panter-Brick, C., Lipson, S. F., & O’Rourke, M. T. (1993). The ecological context of human ovarian function. Human Reproduction, 8, 2248–2258.

Euling, S. Y., Herman-Giddens, M. E., Lee, P. A., Selevan, S. G., Juul, A., Sorensen, T. I. A., . . . Swan (2008). Examination of US puberty-timing data from 1940 to 1944 for secular trends: Panel findings. Pediatrics, 121 (suppl. 3), S172–S191.

Finer, L. B., & Philbin, J. M. (2014). Trends in ages of key reproductive transitions in the United States, 1951–2010. Women’s Health Issues, 24, e271–e279.

Herman-Giddens, M. E., Slora, E. J., Wasserman, R. C., Bourdony, C. J., Bhapkar, M. V., Koch, G. G., & Hasemeier, C. M. (1997). Secondary sexual characteristics and menses in young girls seen in office practice: A study from the Pediatric Research in Office Settings network. Pediatrics, 99, 505–512.

Metcalf, M. G., Skidmore, D. S., Lowry, G. F., & Mackenzie, J. A. (1983). Incidence of ovulation in the years after menarche. Journal of Endocrinology, 97, 213–219.


  1. Man gets a 9yo wife, abandons her before she starts reproducing -> reproductive success = 0.

    Man gets a 9yo wife, holds on to her for long as possible -> reproductive success greater than man who gets a 30yo wife.

    It's not complicated maths.

    1. This comment has been removed by the author.

    2. Right: Man 1 more likely the pedophile. He finds a “wife” of the age he likes and leaves her when she is the age he no longer likes, and his reproductive success is likely low. Man 2 is having sex almost his whole life with an adult, and does not go to look for another 9 year old. He is less likely a pedophile and more likely to reproduce. The more likely the pedophilia, the less likely the reproduction.

      The question is not one of maths at all, but of correctly identifying pedophilia. Only a minority of men with a single child victim are actually pedophilic; it is the men with a sequence of them who are most likely to be pedophiles (Cantor & McPhail, 2015). As noted already, to be a pedophile is to prefer children to adults.

      Cantor, J. M., & McPhail, I. V. (2015). Sensitivity and specificity of the phallometric test for hebephilia. Journal of Sexual Medicine, 12, 1940-1940. doi: 10.1111/jsm.12970

    3. It's clear that exclusive pedophilia would be maladaptive, unless maybe if a man was forced to stay with his wife when she grows up for cultural reasons or something.

      The point I'm making is that the second man who acquired a child bride and committed himself to her would be reproductively more successfull than a man who acquired an older bride with fewer fertile years ahead of her. We must then conclude that men are likely to have evolved adaptations for acquiring child brides and to prefer to acquire child brides than older women. Finding little girls more physically attractive than older women seems to be that adaptation.

      In other words, hetero-pedophilic attraction does seem to have adaptive value rather than just being some kind of byproduct.

    4. No, that is not correct either. A man taking on post-pubescent females would start reproducing immediately, and that would continue until menopause. A man who takes on a 9-year-old, however, would not be spreading any genes until 5-6 years later. Even if he continued to be have sex with her until menopause, he could not out-reproduce the other men who also were with females throughout the female's reproductive life, nevermind "catch up" on the 5-6 years he wasted not reproducing at all.

  2. We should also not forget that the age of first menstruation has fallen for girls in recent years (due to modern diets). 9 year old girls today are around 3 years away from menstruation and a few more years away from being fertile. In pre historic times, when menstruation began later, fertility was also pushed forward.
    Additionally, it's not only true that younger teens are less fertile than women around 20. They're also less likely to have a healthy child and more likely to die in childbirth if they conceive. This is another reason pedo- (or even ephebo-) philia is maladaptive. A younger wife is less fertile to begin with, and more likely to lose their child and to die in childbirth, meaning her husband would need to begin the search for a wife all over again to have a chance at producing more offspring.

  3. >The second part is an idea I have heard before, but I am afraid it is based on some false information.

    They're pointing out that preteen wife has a higher amount of expected future offspring than a 30 year old wife. They never said anything about puberty being the start of a girls fertility.

  4. So you don't think the “kidnap them as girls to get all their subsequent offspring” strategy would work?

    1. It works for Hamadryas baboons!

  5. Isn't it true that most CSA is carried out by men who aren't technically pedophiles? Doesn't this suggest that normal men have the capacity to be aroused by children?

  6. wondeful blog you have posted about pedophilic is useful. Thanks for sharing.
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  7. Ever heard of the anthropologist Kenneth Good? He lived with the Yanomamo people for years and ended up falling in love with and marrying a girl about 9 years old. This type of marriage between little girls and adult men is common in these primitive societies. They were together for almost 20 years and he had 3 surviving children with her. Evolutionarily speaking the relationship was a success and you're refusing to accept that pedophilic could be adaptive?