Access
This article is part of Nature's premium content.
Published online 26 February 2008 | Nature | doi:10.1038/news.2008.625
News
Fertile wives find single men sexy
For partnered women, a manly man with no attachments seems sexiest when she is fertile.
Women beware: instinctive preferences might up the odds of getting pregnant when cheating on a partner.
In a study looking at the ever-interesting (and ever-mysterious) question of why women are attracted to certain men, researchers found that sexual interest shifts with a partnered woman’s menstrual cycle.
To read this story in full you will need to login or make a payment (see right).
Comments
Reader comments are usually moderated after posting. If you find something offensive or inappropriate, you can speed this process by clicking 'Report this comment' (or, if that doesn't work for you, email redesign@nature.com). For more controversial topics, we reserve the right to moderate before comments are published.
women are really double-minded animal
I have to disagree with the following statement: "In many monogamous animals, including marmosets and humans...." How can you describe humans as monogamous, when the overwhelming majority (some studies put the number as high as 80%) of human cultures involve some form of sanctioned polygamy? There is simply no evidence that humans as a whole have a natural tendency toward monogamy beyond societally imposed norms from a minority of cultural groups. This study, viewed from the assumption that humans are not truly monogamously minded by nature, is really not all that surprising. The same behavior is seen in many bird species, who are socially monogamous but mate with others than their established partner. (This is detailed in the book "The Myth of Monogamy".)
The less sexy side of polygamous cultures is that the less desirable, lower quality males get no love from nobody- if they aren’t run off or killed. There usually isn’t a fun reason why there is a sufficient surplus women in a population as to support cultural polygamy. (I can't claim a source for this, though a pocket calculator should suffice.) Polyamorists use this argument to, to a slightly better effect, since there doesn’t have to be a surplus of females, just some extra understanding and bisexuality. That’s all well and good, but I can guarantee you’ll never to have more “conversations about the relationship†then in this arrangement. But it all depends on how worthwhile you are and what you want from your relationships.
Isn't it more likely that partnered women willing to have sexual affairs (at least partly motivated by their cycle) choose single men to reduce the risks/ complications in what is expected to be a purely physical relationship. Note that the study indicates a greater interest in partnered men when partnered women are not fertile and presumably looking for a larger relationship. My badly worded point is that the study's authors cannot claim to have identified "instinctive" choices. The choices by partnered women may be entirely conscious, based on short-term desire or long-term goals.
Roger Armstrong: You are correct that by monogamous we obviously mean "socially" monogamous, not "sexually" monogamous, and this is the case in birds also. As to the 80% polygamy figure you give, it refers to societies that allow polygamy; yet in these societies, 80% of marriages are socially monogamous. Furthermore, over one-third of the world's population lives in a nation where social monogamy is the only legal form of marriage. Whether a marriage system will be monogamous or polygynous depends on several well-studied environmental variables, but in which way does all of this render our female preferences "less surprising"? The novel point of our study is not that people can be unfaithful, but that the partnership status of a man has opposite effects on his facial attractiveness depending on something as apparently unrelated as the lady's fertility status, and only for ladies who have already secured a stable partner.
Bee Kay: Nice point, but. If women were asked to choose between single and coupled men for an affair, it would be likely that their responses would express "entirely conscious choices", as you say. But (1) women were asked to look at pictures of men, labeled as single or variously attached, and simply say how attractive they found their faces; (2) affairs were never mentioned; (3) all women reported being committed to their partners and happy with their relationships. All of this seems to point to instinctive preferences rather than conscious choices, don't you think? Add that (4) most women were not at all aware of their cycle day, and had to check it or compute it mentally when asked. Still the preference for single men only emerged during fertile days (two middle weeks of the monthly cycle, with a peak on days 12-15), and reversed during infertile days (first and last week of the cycle).
This is another reason why women = risky investment. Hehehe.