Reactions to Polygamy Across the Sexes
Women really don't like polygamists—here's why.
Posted Dec 18, 2018
When it comes to the social psychology of biological sex differences, women are often painted as the kinder and gentler sex. They are more likely to be painted as victims across various scenarios (see Reynolds et al., 2018), they score as relatively agreeable in personality compared with males (see Weisberg et al., 2011), and they are more likely to be the beneficiaries of various forms of help compared with men (see Eagly, 1986).
In a recent study published by the New Paltz Evolutionary Psychology Lab (Widman, Philip, & Geher, 2018), however, we found a context in which women seem to be particularly harsh compared with men: sentencing in regard to cases of documented polygamy.
The Nature of Polygamy
Polygamy exists when a relationship includes more than two monogamous partners. For instance, a man might have multiple women as his partners, or vice versa (see Barash, 2016). Polygny, which is the most commonly seen form of polygamy, exists when a man has multiple women as partners. The less-common polyandry exists when a woman has multiple men for partners.
An evolutionary perspective on the relationship between biology and mating behavior can shed light on why polygyny is more common than is polyandry. In short, due to the details of male versus female reproductive systems, men have a much smaller required biological investment to be able to reproduce at all (one sexual act) compared with women, who have very high required parental investment to be able to reproduce (including pregnancy, nursing, and more; see Trivers, 1972).
Social Judgments of Polygyny versus Polyandry
A polygynous mating system, in which a man has multiple women as partners, generally matches this sex difference in required parental investment than does a polyandrous system. For this basic reason, we predicted that in a society like ours, in which both forms of polygamy are illegal, there would be a bias that favors polygyny relative to polyandry. That is, we expected people in a hypothetical sentencing scenario to give relatively harsher judgments in cases of polyandry (when a woman is found guilty of having multiple spouses) compared to cases of polygyny (when a man is found guilty of having multiple spouses).
In our research, we studied over 300 adults from the US, mostly college students in either Pennsylvania or New York. Participants included both men and women. We asked them to make judgments in terms of how harsh they thought the sentences should be for four different target people found guilty of polygamy. Half the targets whom they made judgments about were men while half were women. Further, in half the scenarios, the perpetrator had children while in the other half, the perpetrator had no kids.
It turned out that the sex of the perpetrator had no effect on the harshness of judgments. Participants were not more lenient in thinking about the sentencing of women relative to men (or vice versa), in other words.
However, two substantial main effects emerged. First, if the perpetrator had kids, this fact raised quite an eyebrow: Across the board, perpetrators with kids were given harsher sentences. Second, women were harsher judges, across the board, then males were.
Why Were Women Harsher Judges of Polygamy in this Study?
These findings, of course, raise the question as to why women were harsher in their judgments than were men. As we see it, in a generally monogamous culture like ours, compared with men, women, on average, have, from an evolutionary perspective, more to lose if others in their community are engaging in polygamy. If men are cheating at a high rate, that could be a sign that a woman's male spouse might not be trusted to stick around and help with the family. And if other women out there are mating with multiple men, this could also be a signal of concern. A polyandrous woman might be hoarding all the good men! For men, the costs of others having multiple partners in the community would, on average, present less of a biological tax as men have, on average, less of a biological investment in offspring compared with the investment that women have.
When it comes to sex differences in doling out punishment, men are often framed as being the relatively harsh sex. When it comes to judgments related to polygamy, it seems that women are more willing to give out relatively harsh sentences compared with men. From an evolutionary perspective, both standard forms of polygamy, polygyny (one man having multiple women) and polyandry (one woman having multiple men), could signal hurdles to a woman's own ability to effectively bear and raise offspring.
Barash, D. P. (2016). Out of Eden: The Surprising Consequences of Polygamy. New York: Oxford University Press.
Eagly, A. H., & Crowley, M. (1986). Gender and helping behavior: A meta-analytic review of the social psychological literature. Psychological Bulletin, 100, 283-308.
Reynolds, T., et al. (2018). Man up and take it! Greater concern for male than for female suffering. Presentation given at the annual meeting of the Human Evolutionary Behavioral Society. Netherlands.
Trivers, R. (1972). Parental investment and sexual selection. In B. Campbell (Ed.), Sexual selection and the descent of man: 1871-1971 (pp. 136-179). Chicago: Aldine.
Weisberg, Y. J., Deyoung, C. G., & Hirsh, J. B. (2011). Gender Differences in Personality across the Ten Aspects of the Big Five. Frontiers in psychology, 2, 178. doi:10.3389/fpsyg.2011.00178
Widman, D., Philip, M., & Geher, G. (2018). Punishment of Hypothetical Polygamous Marriages. Evolutionary Behavioral Sciences. http://dx.doi.org/10.1037/ebs0000155