Criminals have more kids. July 2014

Thursday, July 24, 2014 Rob 7 Comments

This month, crime pays: we discover the link between criminal behaviour and reproduction, and find out why it makes sense to judge your criminal accomplices on their beauty. We also learn what a woman’s bank balance says about her attitude to promiscuity.

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New research shows that criminal offending might be part of an alternative reproductive strategy. That explains why the Godfather was the head of such a huge family, then.

The articles covered in the show:

Yao, S., Långström, N., Temrin, H., & Walum, H. (in press). Criminal offending as part of an alternative reproductive strategy: Investigating evolutionary hypotheses using Swedish total population data. Evolution and Human Behavior. Read summary

Shinada, M., & Yamagishi, T. (in press). Physical attractiveness and cooperation in a prisoner's dilemma game. Evolution and Human Behavior. Read summary

Price, M. E., Pound, N., & Scott, I. M. (in press). Female economic dependence and the morality of promiscuity. Archives of Sexual Behavior. Read summary


  1. Wait a minute. If people with criminal personalities have been the reproductively most successful for long enough they would have come to dominate in society. Could this just be a very modern phenomenon? Maybe in the past criminals left behind fewer offspring.

  2. Yes, there is no way of knowing whether the same would have been true 10,000 years ago. Crime is something of a modern idea too: it relies on laws existing.

    I suppose not every human behaviour has to have been adaptive over all of our history. Maybe 'criminals' were unsuccessful way back, but their reproductive success was better during this period of history due to cultural circumstances that favoured them.

  3. tyrion lanister3 August 2014 at 11:07

    "why it makes sense to judge your criminal accomplices on their beauty"

    Most findings suggest the opposite:

    1)Lombroso observed the physical characteristics of Italian prisoners and compared them to those of Italian soldiers. And the physical characteristics that he used to identify prisoners included an asymmetry of the face or head, large monkey-like ears, large lips, a twisted nose, excessive cheekbones, long arms, and excessive wrinkles on the skin. Criminal Man (1876).

    2) Verdum et al also did an anthropological study of 33 criminal delinquent adults & 41 juvenile delinquents; they found increased proportion of alterations of the constitutional morphology.

    3) Hooton measured the physical characteristics of 13,873 criminals from ten states (which included Massachusetts, Tennessee, Kentucky, Texas, North Carolina, Wisconsin, Missouri, New Mexico, Colorado, and Arizona)and compared them to a control sample of 3,203 non-criminals from Massachusetts, Tennessee, and North Carolina in order to make clear any differences between the two groups all adult-male groups (Hooton, 1939c: 35). His measurements included such physical characteristics as weight, height, head length, nose height, and ear length. Countless other measurements (107 in total) were taken from each subject including age, religion, education, offense committed, marital status, I.Q., eye color, moles, tattooing, and race (Hooton, 1939c: 37-47). Hooton attributed criminal behavior to biological inferiority and "degeneration," ascribing a variety of unattractive physical characteristics to criminals (including sloping foreheads, compressed facial features, drooping eyelids, small, protruding ears, projecting cheekbones, narrow jaws, pointy chins, and rounded shoulders).

  4. tyrion lanister3 August 2014 at 11:11

    @ Anonymous,

    It depends of social environments. Non-State societies usually have rewarded such behaviors with success, including reproductive success. But State societies punish young men who act violently on their own initiative. Thus, given the moderate to high heritability of male aggressiveness, the State tends to remove violent predispositions from the gene pool while favoring tendencies toward peacefulness and submission.

    Anthropologists have documented a consistent historical pattern and if we have:
    1-strong skew in mating frequency in which a few males obtain most of the matings, while the rest have little or no succes, the extent to which particular individuals monopolize breeding, or
    2- male based sex ratio in the direction of a smaller proportion of females,

    Then, excluded men (lower mate value) become increasingly competitive, becoming more likely to engage in risky, short-term oriented behavior including gambling, drug abuse, and crime. This sort of pattern fits well with the rest of the biological world. Decades of work in behavioral ecology has shown that in species in which there is substantial variation in mating success among males, males compete especially fiercely.

    The precise details of the route from a biased sex ratio to anti-social behavior in humans is not thoroughly understood, but one possible physiological link is that remaining unmarried increases levels of testosterone—often simply referred to as “T”—which in turn influences decision making and behavior.

    The differences between societies that allow polygyny and those that don’t are potentially illustrative. In societies with polygamy, there are, for obvious reasons, larger numbers of unmarried men than in societies that prohibit polygyny. These unmarried men compete for the remaining unmarried women, which includes a greater propensity to violence and engaging in more criminal behavior than their married counterparts. Indeed, cross-national research shows a consistent relationship between imbalanced sex ratios and rates of violent crime. The higher the fraction of unmarried men in a population, the greater the frequency of theft, fraud, rape, and murder. The size of these effects are non-trivial: Some estimates suggest marriage reduces the likelihood of criminal behavior by as much as one half.

    Further, relatively poor unmarried men, historically, have formed associations with other unmarried men, using force to secure resources they otherwise would be unable to obtain.

    A good example would be sub-Saharan Africa. Since the incidence of polygyny is high (over 20% of all marriages), there is typically a surplus of young single males. These societies often resolve the destabilizing influence of these males by stationing them on the periphery of their territory in warrior camps. This set-up, in turn, is conducive to endemic warfare, since war is usually the only way these men can get access to women.

  5. Thanks for the comment, Tyrion!

    The study I was talking about is not really to do with criminals. I only framed it that way because I was segwaying from a study that was actually about criminals, and because Shinada had her participant's play the prisoners' dilemma game.

    I hadn't heard about these studies you mention. It sounds like the authors were trying to show that criminality and physical abnormalities or distinctiveness are somehow related. I suppose if people fall on hard times, they are more likely to turn to crime AND to suffer disease, poor nutrition, injury due to working at manual jobs, etc, which might manifest physically explain the results. Or it could be that people who naturally look this way are shunned by mainstream society and turn to crime.

    If you've not already heard it, you might be interested in the episode from March 2010 in which I speak to Tyler Stillman of Florida State University about whether we can identify violent criminals just by looking at their faces:

  6. @ Rob,

    Regarding to "Criminal offending as part of an alternative reproductive strategy" study,
    my thoughts on this topic are reflected in this article:

    Chicks dig jerks?: Evolutionary psych on sex

    And I've also discussed this issue on my blog:

  7. Some what surprising I would have thought! They're probably encouraging their kids to carry on their crime!


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