This is less of a post than a news item. My collaborators and I have recently been involved in some in-press debate with Lisa de Bruine, Ben Jones, Tony Little and their colleagues about a study they published earlier this year in Proceedings of the Royal Society of London. They have a wonderful ongoing project studying women’s preferences for men’s faces (visit www.facelab.org to participate), and in their paper they estimate how strongly women from various nations prefer very masculine faces. To do this they do some very clever manipulation, ending with images of the same man’s face that are more or less masculine.
They then compared the strength of these preferences for masculine faces with the standard of health in thirty countries, and found that where health is poor, women prefer more masculinized faces. My collaborators and I spotted that this could, alternatively, be because those poorer countries also have greater inequality between the richest and the poorest households. Evolutionary psychologists have long known that inequality leads to strong competition among men and more violence, and we wrote to the journal that perhaps women prefer the most masculine men where household income and security depends more on male aggression and status. Because de Bruine and her collaborators had made their national preference scores public, as part of the original publication, we were able to test this prediction and we found that income inequality (the Gini index, often used by economists) is a better predictor of variation among countries in preferences for masculinized faces. We also showed that homicide rate is a promising correlate of preferences – with countries where homicide rate is high also preferring more masculinized faces.
Soon after we submitted this piece, I was at a conference organised by Tony Little and I got to meet Tony, Lisa and Ben for the first time. They were very gracious about our critique and Lisa gave a fabulous and very balanced talk about their paper, our critique and their response. They have since shown, both by further analysing our data and by analysing new data of their own, that health might still be a better predictor of preferences for masculinity than income inequality is. They studied the preferences of 8338 women from the USA, comparing preferences for masculinity among states with health, homicide and income inequality statistics. Within the USA, health seems to be the best predictor of preference for masculine faces.
This week, the Economist ran a very nice story about these papers, giving a great overview of the discussion and the issues that the various papers raise. This is an interesting story that is only going to get more interesting as we step away from correlative analyses and test the various ideas directly. In fact, Little, de Bruine and Jones are doing just that. The idea that mating preferences could vary nationally with a suite of ecological/economic traits is fascinating, and I am sure with some creative experiments and studies we will learn an enormous amount about the causes of this variation. We are also likely to learn a lot about fine-scale variation within countries and even as individuals circumstances change.
Dealing with Lisa, Ben and Tony over this idea has been an absolute pleasure. It is never fun having people critique your published papers, but this has been a positive and constructive discussion. I hope the field is better off for it.
See also post on Clipped News