In an earlier post, I discuss Finkel and Eastwick's fascinating finding that, under some circumstances, women can be just as indiscriminate in mate choice as men are, and, in the followup post, suggest one possible evolutionary psychological explanation for it by my colleague. Now a very insightful reader offers another possible explanation.
Just to recap, Finkel and Eastwick's experiment using the speed-dating format showed that, when men rotate among women, women were much more selective in mate choice than men (as one would expect), but when women rotate among men, they were just as indiscriminate and aggressive in mate choice as men were. Since sex differences in mate selectivity is a deeply ingrained part of male and female evolved human nature, it doesn't make sense that the typical pattern can be so easily reversed by a temporary change in the institutional arrangement of who approaches whom.
My friend and colleague, Diane J. Reyniers, then offered one possible explanation based on the Savanna Principle about the evolutionary limitations of the human brain. Because the experimenters were forcing the women to approach men, when women seldom approached men throughout evolutionary history unless the man happened to be exceptionally desirable, the temporary institutional arrangement may trick women's brains into thinking that the men they were approaching were exceptionally desirable. As a result, they may say "yes" to a much higher proportion of them than usual.
Now, a regular reader of my blog, Mr. Alok Lal, offers another possible explanation for Finkel and Eastwick's finding from an evolutionary psychological perspective. Mr. Lal's explanation also relies on the Savanna Principle, and involves a well-known phenomenon of mate copying.
Studies have shown that females of many and varied species have a tendency to copy the mate choice of other females. Given a choice to mate with a male who has recently mated with a female or another male who has not recently mated, many females prefer to mate with the former, not the latter. This is probably because females of these species trust each other's judgment. If another female found a male to be of high enough genetic quality to mate, then he is expected to be better than another male whom no females have chosen recently.
The principle, applied to humans, is known as the wedding ring effect, and explains why some women may prefer to mate with married men. If another woman has judged him to be of high enough quality to marry, presumably after a long period of courtship and careful examination, then he could not possibly be a complete loser, which is more than one can say about another man whom nobody has chosen to marry. An unmarried man may be of very high quality, but he may also be of very low quality (because he's completely unknown), whereas a married man could not be of very low quality; in other words, married men have guaranteed minimum quality.
While it is an intriguing idea, which has well-established analogs in other species, the empirical evidence for the wedding ring effect among humans has so far been mixed. Some experiments find that women are more attracted to married men than to single men, but other experiments don't. Most recently, as she discusses in her post, a 2009 study by the new PT blogger Melissa Burkley finds that women do find attached men more desirable than unattached men, but only when the women themselves are unattached.
Mr. Lal reasons as follows. While women are rotating among men in the speed-dating event and approaching men themselves, they could be observing what other women in the room are doing. (This is very plausible given how competitive women are in the mating arena, especially at a speed-dating event.) They could be observing, in the corners of their eyes while talking to their "dates," that other women are approaching the men in the room. Once again, because women did not routinely approach men throughout evolutionary history, this could trick women's brains into thinking that the men in the room at their speed-dating event must be of high genetic quality. In an attempt to copy the mating effort and judgment of other women in the room, the rotating women may become more likely to say "yes" to more men in the "men sit, women rotate" condition.
Just like Diane's explanation earlier, I think Mr. Lal's is also very plausible. One way to adjudicate between the two evolutionary psychological explanations is to create a condition where women approach men but cannot see other women do so. If Diane's explanation is correct, women in this condition should still be indiscriminate in their mate choice; if Mr. Lal's explanation is correct, they shouldn't be. Alternatively, one can create a condition where women observe other women approach men but themselves do not approach them. If Diane's explanation is correct, women observers should not be more likely to find the men attractive, whereas if Mr. Lal's explanation is correct, they should be. In general, if there are two mutually exclusive categories of men (those that women themselves approach, and those that they observe other women approach), then Diane's explanation leads us to predict that women will be attracted to only the first category of men, whereas Mr. Lal's explanation would predict that they will be attracted to only the second category of men. Of course, there is always the possibility that both explanations are correct and can partly account for Finkel and Eastwick's findings.
As an aside, Mr. Lal was trained in mechanical engineering and currently works as a software engineer. He does not have any background in psychology, let alone evolutionary psychology, and has not taken any biology class since high school. (But then again, neither have I.) The fact that someone like Mr. Lal can offer a very insightful explanation of a puzzling phenomenon from an evolutionary psychological perspective suggests that Robert Wright's words in his 1994 book The Moral Animal are still true today: "For now, this is the state of evolutionary psychology: so much fertile terrain, so few farmers." The field of evolutionary psychology is still wide open. Anyone who is interested in the topic and has bright ideas, like Mr. Lal, can make a contribution to the field.