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 more 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?

    1. Yeah, I've heard of him. Apparently romances and marriages between adult men and pre-pubertal girls are common in primitive foraging societies. Here in the West we think they're abnormal but they're actually part of the natural human mating system. It makes more biological sense for a man to commit himself to a virgin 9 year old than a 30 year old who's used up half her fertile years.


    2. >https://mapbiology.wordpress.com/

      Interesting site, especially the part about mating beginning before the females start ovulating.

      I've done some more research into the onset of mating in all the apes. Chimp and Orangutans start mating about 10 and start ovulating about 12-13. Bonobos start having intercourse about 8 and start ovulating about 12. For gorillas the ages are about 8 and 10.

      On average the age of the onset of mating is roughly 80% of the age of the onset of ovulation.

      Healthy human females typically start ovulating about 16 and if we followed the same pattern as the other apes we'd expect mating to start about 12/13 kind of age.

      Naively, we'd predict that mating would begin only once the females have become fertile. It's interesting that nature is bit more complex than that.

    3. Dr. Cantor, do you think girls grow boobs in puberty to signal their readiness to start mating, similar to sexual swellings in other primates?

      Chimp females start puberty at about 8 and by the time they're about 10 they've developed sexual swellings on their arses. Their arses basically swell up and this signals that they're ready to start mating. The males start mating with them at this age but they don't actually start ovulating and become able to conceive until a few years later.

      Human females appear to follow the same pattern but just a few years later. They start puberty about 10, by the time they're about 12/13 they've developed "sexual swellings" on their chests that signal they're ready to start mating and, similarly to chimps, they don't actually start ovulating until several years later.

      In both cases the females develop sexual advertisements and become ready to start mating several years before they're ready to start reproducing.

  8. What do you think of my infographic about hebe/ephebophilia?


  9. Informative article, just what I wanted to find.

  10. Interesting comment on this article I thought you might want to read.


    >Natural selection is expected to drive toward a preference for opposite-sex, sexually mature persons, because individuals who do not have this preference are expected to be less likely to reproduce and thus are less likely to pass on their preference for partners who are not opposite-sex and sexually mature.

    The problem is that in order to predict what preferences will lead to the greatest reproductive success we have to know what mating system a species uses.

    Mating systems vary widely across the animal kingdom. There are insects in which the females mate with their infant sons. There are weasels in which the males sneak down into nests and inseminate the baby females when the mother goes out to feed and have no interest in adult females. Chimp troops are a kind of sexual free-for-all and the males prefer older females towards the end of their reproductive lifespans.

    Without knowing what mating system ancestral humans used you can’t say anything about the reproductive success certain age preferences would have lead to.

    I think many people have this kind of vague image in their heads of ancestral men going about impregnating various females. Pump and dump strategy. Inseminate this female one day and another female the next.

    If this was how the human mating system worked it would be true that preferences for the most fertile adult females would lead to the greatest reproductive success for men. The trouble is that this is not how the natural human mating system works. In no society on Earth does most reproduction happen from short-term pump and dump matings.

    In every society men keep wives that they copulate with regularly and guard from other men. In this kind of mating system a preference for pursuing sub-fertile or pre-fertile females can easily lead to greater reproductive success than a preference for adult females for the simple reason that the younger less fertile females are capable of giving a man more offspring over the long-term than adult females who have used up some of their fertile years.

    Suppose females go through 6 pregnancies over the course of their lives. The actual figure varies a bit across primitive foraging societies, some it’s 5, some it 8, but let’s just use the figure of 6. A 25yo woman would have already been through 2 or more pregnancies and only have about 4 left. A 12yo girl would still have all 6 remaining. A man who preferred to pursue and acquire 12yr olds could easily have a higher reproductive success than a man who preferred 25yr olds even though 12yr olds have a lower current fertility and are less likely to get pregnant from a single mating.

  11. Is it possible for multiple factors to contribute in the manifestation of pedophilia? If some factors make one a pedophile, and those are the same factors that might make him have lower IQ, to be left handed and/or shorter (in average), is it possible for there to be other factors that make someone pedophile, but don't increase the likelihood of him being dumber, shorter or left-handed?
    As far as I understand, correlation does not imply causation.
    In your studies, you used sexual offenders. Is it possible that the factors which made them less intelligent/left handed and shorter in average, make them more prone to sexual offending, and for that to have nothing to do with pedophilia itself?

    I believe that many people believe that all pedophiles are dumb, left-handed and short because popular websites interpret your studies in a wrong fashion, which make a big disservice to pedophiles.

  12. Dear Dr. James,

    Why do men in primitive foraging societies consider the young teen girls who haven't had a baby yet the most attractive? Wouldn't it make more sense to prefer the adult women who have already had offspring and proven their fertility?

  13. >That is, a man who focuses his energies on women in their
    >20s would produce more 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).

    LOL, is that what they taught you in high-school biology?

    1. If current fertility is so important than why haven't men evolved to only mate with women during their fertile window, or at least prefer women in their fertile phase regardless of age?

      Having sex with a 15 or 40 year old in her fertile phase of the month is more likely to result in conception than having sex with a 25 year old during her non-fertile phase. So shouldn't we expect men to evolve to detect when women are fertile and find them the most attractive in that phase of the menstrual cycle, like chimps do?

      But we don't find that, because that's not how the human mating system works.

      Because we form long term relationships what matters most is a woman's long term fertility and the amount of offspring she can be expected to produce over the long term. This is why a woman's attractiveness is more closely correlated with her reproductive value than her current fertility that undulates over time.

      This is basic evolutionary biology that's been understood for decades. I can't believe you people don't know this stuff.


  14. Dr. Cantor, could the frequencies of male chronophilias be bi-modal, as in this graph?


  15. Does hebephilia overlap more with ephebophilia or pedophilia?

    1. Ephebophilia has not been studied very much at all, so any answer must be tentative. In general, it seems pretty equidistant. In general, individual people are more accurately described by their "age range of attraction," such as being attracted to people to 6 to 12, or 10 to 16, etc. That is, the innate attractions do not appear to follow the diagnostic labels very closely, if at all.

  16. A recent study found that women's desirability on dating sites peaks about 18. Take a look at the graph:


    Of course since the sites don't allow under 18's the graphline is truncated and presumably continues to rise for a few years under 18 too. Maybe something like this:


    What do you think?

  17. Do you think it might turn out that most men have an instinctive preference for girls about 14, since it was the ancestral human mating system to get females that age, but that most men don't act on or suppress this preference since it's against our modern laws and social norms?

    I'm just thinking out loud here.

  18. https://www.psychologytoday.com/gb/blog/attraction-evolved/201812/does-hourglass-figure-really-signal-fertility