War, humor, and breastfeeding.
The July issue of Personality and Social Psychology Bulletin (PSPB) recently came out, and includes several articles written from an evolutionary perspective. (As an aside, a few people have asked me about the hiatus since the last post. The reason for the pause is pedestrian: I recently moved back from the West Coast to the East Coast, and had limited time for blog-related activities during my transition. Expect more gaps during some summer travels, but please feel free to continue to send me ideas for posts.)
In any case, I thought I would discuss some papers from this issue of PSPB of potential interest to evolutionary people, and do a little Compare And Contrast exercise with a couple of non-evolutionary papers.
Two papers drew on sexual selection, but about two disparate content areas, warfare and humor. Chang et al. were interested in the possibility that the large difference between men’s and women’s participation in warfare might have something to do with sexual selection. In the first of three studies, they showed men and women attractive and unattractive opposite-sex people and asked them questions related to war or trade. Impressively, they got the three-way interaction: Men (but not women) primed with attractive pictures of people of the opposite sex showed an increase in willingness to go to war relative to men primed with unattractive women. They conducted three other studies all designed to get at this idea, but in slightly different ways, priming mating in one way or another, and looking at measures related to warfare.
On a lighter note, Wilbur and Campbell were interested in the idea that humor is used in the context of mating, as a signal (a la Geoffrey Miller). They conducted three studies, the second of which used profiles from a dating site (lavalife.com), to investigate the frequency with which men and women offer as opposed to request the production of humor in the narrative portion of their profiles. ( “I can make you laugh” vs. “Looking for someone who can make me laugh.”) The results are as predicted, with men more frequently doing the offering and women more often doing the requesting.
Thirdly, Sacco et al, drawing on life history theory (and Kenrick et al., 2010), suggested that people who are “socially included” will devote more energy to mating effort. The general idea is that there are tradeoffs that must be made, and if one is socially included, then one can devote more time and energy to the adaptive problem of finding mates as opposed to building one’s social network. They ran a series of three studies, manipulating social inclusion with priming techniques (e.g., writing about a time the subject was accepted by others, etc.), and looking at responses related to mating. They summarize their results as follows (p. 994).:
In Experiment 1, men who were made to feel included indicated greater approval of sexual aggression (i.e., acquaintance rape) as compared to excluded or control males. In Experiment 2, we found that risky mate poaching tactics were more likely to be endorsed by socially included men, relative to excluded or control men. Women’s global mate poaching endorsement, in contrast, remained constant across conditions. Finally, Experiment 3 extended these results by showing that socially included men also more strongly endorsed risky tactics related to mate retention. Replicating Experiment 2, women again showed no changes in endorsement of mate retention tactics.
My experience is that three articles based in evolutionary theories is a lot for PSPB. So that’s interesting. But these papers also made me think a little bit about some of my recent experiences. Over the last several months, I have given more talks to non-academics than I normally do, and I have frequently been asked what differentiates the evolutionary approach to social science from other approaches. These three articles all begin with theories drawn from the literature in biology – sexual selection and life history theory – and derive some ideas about proximate psychological mechanisms. Compare this approach to that taken in two papers from the same issue of PSPB. (I didn’t choose them at random. I looked at the first one because the title led me to believe it was about kin selection – “Highlighting Relatedness Promotes Prosocial Motives and Behavior” – but I was completely wrong; it had nothing to do with kin selection. The second one I thought also might be relevant to evolutionary psychology because it was about breastfeeding: “Spoiled Milk: An Experimental Examination of Bias Against Mothers Who Breastfeed.”)
This latter paper tested the hypothesis that “breastfeeding mothers are the victims of bias.” The theory from which this hypothesis was derived was “objectification theory.” This theory is that “in Western society, individuals—particularly women—are subject to experiences that highlight body parts as “things” to be used or looked at by others.” The former paper, the one on relatedness, uses “self-determination theory” as a starting point, which is the theory that “people have three basic psychological needs: relatedness, competence, and autonomy.” (To give a sense of what these authors were up to, they primed “relatedness” – nothing to do with kinship; more like social inclusion – with a sentence unscrambling task and then asked about their likelihood of volunteering over the next six weeks.) They reasoned as follows: “Relatedness need satisfaction is likely to be particularly important for promoting prosocial behavior because of the increased sense of connectedness to others that this engenders.” (As something of an aside, it’s interesting to contrast this with the work on social inclusion discussed above. Both papers are about, roughly, social inclusion. In one case, the prediction is that it will make one more likely to engage in some unpleasant behaviors – including sexual coercion – and in the other case the prediction is for altruism. Interesting that both predictions were borne out.)
In any case, the contrast is that the three papers I began with start with an ultimate theory and use that to get to thoughts about the proximate psychology. The latter two papers have theories that are quite different. The first theory is really an observation, that women have certain kinds of experiences, and the second theory is in the language of folk psychology, referring to “needs.”
I would suggest that this pattern in evidence in this issue of PSPB does a fairly good job of illustrating the two ways researchers approach the study of human social behavior.
References
Chang, L., Lu, H. J., Li, H., & Li, T. (2011). The face that launched a thousand ships: The mating-warring association in men. Personality and Social Psychology Bulletin, 37, 976-984.
Kenrick, D. T., Griskevicius, V., Neuberg, S. L., & Schaller, M. (2010). Renovating the pyramid of needs: Contemporary extensions built upon ancient foundations. Perspectives on Psychological Science, 5, 292-314.
Sacco, D. F., Brown, C. M., Young, S. G., Bernstein, M. J., & Hugenberg, K.. (2011). Social Inclusion Facilitates Risky Mating Behavior in Men. Personality and Social Psychology Bulletin, 37, 985-998.
Smith, J. L., Hawkinson, K., & Paull, K. (2011). Spoiled Milk: An Experimental Examination of Bias Against Mothers Who Breastfeed. Personality and Social Psychology Bulletin, 37, 867-878.
Pavey, L., Greitemeyer, T., & Sparks, P. (2011). Highlighting Relatedness Promotes Prosocial Motives and Behavior. Personality and Social Psychology Bulletin, 37, 905-917.
Wilbur, C. J., & Campbell, L. (2011). Humor in Romantic Contexts: Do Men Participate and Women Evaluate. Personality and Social Psychology Bulletin, 37, 918-92.
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