Finally I have finished reading two academic articles: "Menstrual cycle, trait estrogen level, and masculinity preferences in the human voice" and "Adult attachment and the perception of emotional expressions" which I will present later.
The first one follows in the tradition of some recent EP work that shows changes in a woman's hormonal condition coincide with different preferences for sexual partners. The interesting findings show up for non-hormone based contraceptive using women around the time they ovulate (release an egg and can become pregnant). I mentioned this in class once and found that some of the men thought ovulation was when women had their periods. I was shocked; I learned something valuable that day in class to say the least.
But back to the real story:
In a nutshell, fertile women find more masculine looking men more attractive than they do more rounded, feminine looking men. EPs assert that at the time women are most likely to become pregnant they prefer 'good genes' signals from potential partners. Masculine facial features, such as a protruding brow ridge and prominent chin, represent secondary sexual characteristics that develop in response to testosterone.
Because testosterone exerts harmful effects on the immune system, anyone who has masculine features and also appears to be healthy basically signals that they have a strong immune system. Of course, we also assume people are healthy if they are attractive, and sometimes we are wrong. Attractive people are not necessarily in better condition. But, more often than not, they are.
By preferring men who are more masculine looking at the time they are most likely to conceive if they have vaginal intercourse with that man, women increase the odds that their child will have 'good genes' in the good immune system sense. It's sort of like female peahens preferring to mate with peacocks who have gloriously long, symmetrical, colorful tails. Those tails handicap the owners, slowing them down. Any male who has managed to carry around such a burden without being damaged or eaten sends the message that he is a high quality bird. The ladies flock to him. EPs have run with Zahavi's handicap principle.
This article is just the latest installment. Rather than using facial stimuli Feinberg et al use vocal stimuli. They had men and women pronounce vowels which were then tweaked up or down in pitch to masculinize and feminize them. As expected, the authors found that menstrual cycle affected preference for masculinized voices - but - only for male voices - and - especially for women who had low circulating estradiol levels, i.e. less feminine, less attractive women.
EPs refer to high estrogen women as "feminine and attractive" because of the connection between estrogen and waist-to-hip ratio and feminine facial features such as full lips. The preference for masculine male voices was more pronounced for "lower quality women."
What was interesting about this article was the lengths the authors went to in order to explain that finding. First, they cited previous research that found preferences for masculinity were most robust for short term mating (STM) contexts (i.e. evaluating a partner for a one-night stand as opposed to marriage). Next they present research that found low-E women were more likely to engage in STM. The authors propose that high-E women are more able to get high quality (i.e. masculine) men as long-term partners and the cost to them of choosing a high quality man is lower.
The authors don't really explain what the "cost" is, but I think they mean that high-T men will be less likely to "dump" a high-E woman. People who match each other in terms of "mate value" are more likely to stay together. It's very much like Joey's advice on Friends. Hit on someone who is a max of +/- 2 away from you in attractiveness. If you're a 6, aim for 4-8. Don't waste your time trying to get a 10 who will leave you when another 10 comes along.
So, we could read this article as a study of condition-dependent mating strategy.
What doesn't make a lot of sense at first glance is that women in comparatively 'poor' condition set their sights even higher than women who are in 'good' condition.
Lower quality women appear to want 'good genes' even more, but are they likely to get them?
Well, they do have more sex partners, so someone is mating with these women. Previous research has found that men lower their standards for STM, so a woman in relatively poor condition will be able to mate with a high quality man and maybe become pregnant by him, but she had better be self-sufficient. A woman in good condition (such as Aishwarya Rai, above, you may recognize her from Bride & Prejudice) could do both. She could have the 'good genes' and the 'good provider.'