Crime and selection of aggressive males

As I posted a couple of months ago, a higher level of violence in a society may lead women to prefer more masculine appearing men. In such an environment, picking the healthiest appearing male is more important than the level of parental care the woman expects the man to give.

ResearchBlogging.orgThe latest issue of Evolution and Human Behavior has an article examining the link between female preference and violence, with Jeffrey Snyder and colleagues examining whether a woman’s fear of crime might be a predictor of her preference for “aggressive and formidable” mates. Unlike earlier research, which focused on actual violence levels, Snyder and colleagues’ targeted their hypothesis at the woman’s perception of her vulnerability to crime. This makes sense, as the need for an aggressive man is likely to be a function of both the level of crime and the woman’s ability to defend herself. The woman’s perception of her vulnerability should capture both of these elements.

Snyder and colleagues also framed the trade-off around outcomes to the women instead of reproductive outcomes. Instead of asking whether the aggressive man will deliver a healthy child or invest in parental care, the trade-off discussed concerned violence to the woman by the aggressive man versus the protection he can offer the woman.

Using three internet based studies of United States women, Snyder and colleagues supported their hypothesis through the discovery of a positive relationship between a woman’s perception of her vulnerability to crime and her preference for aggressive men. However, there was no or a very weak link between female mate preference and actual crime rates (which were determined by zip code). This is somewhat confusing, as it suggests that fear of crime may not be rationally based. Snyder and colleagues’ hypothesis would predict a weaker link between actual crime and preferences than between perceived vulnerability and preferences, but there should still be a link.

A further issue with the results is the low-level of effect that the perception of crime has. While it comfortably passes the significance tests, fear of crime can only explain (at most) 5.5 per cent, 7 per cent and 6 per cent of the variation in preferences for aggressive men across the three studies (and that is including other variables in some of the regressions including race, age, education and inequality). This suggests that while perceived vulnerability is significant in a statistical sense, it has very little predictive power.

Having mulled on this study for a couple of days, I am not sure what to make of it. I find the hypothesis attractive, but the absence of a link to actual crime leaves me with a large number of questions about the survey methods used and suggestions for follow-up research – a number of which were also noted by Snyder et al.

First, it would be useful to get some more variation in the sample. The study participants were highly educated, with less than ten per cent of the sample in each study having a level of education at high school level or below. As a result, there are likely to be very few in the sample who live in a violent area. This variation may be particularly important if the survey subjects are subject to levels of crime too low for protection from aggressive men to matter.

More variation could be introduced by including other countries or particularly high crime areas. In those countries or areas, a more masculine male may deliver much stronger benefits and be more strongly preferred.

A related observation is that for this study’s well-educated participants, the easier way to avoid crime would be to marry a rich man. As a result, women in this sample might want to avoid aggressive men. However, that may not be a feasible choice in Sudan or for some inner-city residents. Are these preferences stronger where the best response to violence is a violent response?

Second, and as suggested in the paper, finding out what these women actually do as opposed to their survey responses would be useful. Apart from the obvious benefits to seeing revealed preferences, this might also help to calibrate the responses. In each survey, the women were asked their responses to characterisations such as “bad-boy”, “broad shouldered” and “strong”. If a well-educated woman thinks an accountant with a motorcycle is a bad boy, that is probably a different level of masculinity compared to someone seeking physical protection from a real risk of crime.

I would also like to know more about the women in the survey. Are they in a partnership or married? How tall are they? Have they been a victim of crime? Does their fear of violence come from in the home or from people they know? How much property do they have which could be appropriated in a crime? This might help find some explanatory variables with some real predictive power. However, to test the basic hypothesis, we need a sample with more variation in the levels of violence and ideally, a sample in which we can observe real choices.

I don’t believe that this story sheds much light on my earlier ruminations on violence (most recent here) and the importance of a shift away from violence to allow characteristics such as hard work, intelligence and patience to be rewarded and spread through the population. It could be argued that as the study was conducted in a developed country, and among educated women in that country, we would expect violence to be a trait associated with low fitness. You would expect women to generally favour other traits, with the aggressive characteristics to be secondary and only accepted if they do not come at the cost of economically important traits. Again, to test this idea, we require more variation in the sample. We would need some of the sample to come from populations in which crime brings benefits to its purveyors and results in reproductive success.

Snyder, J., Fessler, D., Tiokhin, L., Frederick, D., Lee, S., & Navarrete, C. (2011). Trade-offs in a dangerous world: women’s fear of crime predicts preferences for aggressive and formidable mates Evolution and Human Behavior, 32 (2), 127-137 DOI: 10.1016/j.evolhumbehav.2010.08.007


  1. I share your concerns about the usefulness of the data set because it doesn’t represent that population that the study cares about measuring. The really powerful numbers to have would be studies of how men with criminal convictions compare to other men in reproductive fitness in an evolutionary sense.

    I haven’t seen any really good careful measuring of those numbers. But, the best figures that I’ve seen say that about half of men in prison have children, which would be well below the norm for men of that age.

    But, men in the demographics that disproportionately produce inmates tend to have children young and have children out of wedlock to a greater extent than me in demographics that disproportionately do not produce inmates. And, there are incentives for both the men (child support payments) and the women (having a convicted criminal having a say in their child rearing without making economic contributions to the family) to be less than diligent in accurately reporting all instances of paternity – and sometimes one or both may simply not know. Mothers who have children who have criminal fathers may have a strong incentive to remove the other parent from their life or cuckhold (perhaps with the mate’s knowledge and consent in the interests of the best interests of all of the family’s children).

    Anecdotally, at least, juvenile delinquents and young felons are much more likely to have children than same age non-delinquents and young non-felons.

    But, perhaps they pay a penalty later in life in ability to find women to mother their children. Also, there is been a stark decline in lifetime fertility rates in low SES women, which has fallen below that of high SES women for the first time a century or two within the last couple of decades (driven mostly by greater use of contraception).

    The combined effects of shorter generations and unreporting may outweight the apparent reproductive fitness penalties of criminal convictions. Having three children at age 30 and two at age 20 are equivalent from a population genetics perspective. Presumably, having 1.8 children on average at 32 (a typical high SES pattern) and having 0.9 children on average at sixteen (a not uncommon low SES pattern) are similarly equivalent.

    Assortive marriage trends may also make marrying a rich man a less viable strategy than it once was, although given that a mere middle class man may be more than sufficient to remove the bulk of the risk of violence, this impact may be moderate.

    1. I agree that in assessing fitness, the length of generations tends to be missed.

      As for the effects of assortive marriages, I would assume that the vast proportion of the United States population would be living in a relatively low crime area, with a small proportion of inner city urban poor experiencing significantly elevated crime. If my assumption is correct, it probably doesn’t take too much of a step up in income to get out.

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