Thursday, February 14, 2008

The Best Men Are (Not Always) Already Taken

Bressan1 and Stranieri take a (dubious) evolutionary psychological approach to the question of female preference for single versus attached males. The outcome is interesting. Here is their abstract:
Because men of higher genetic quality tend to be poorer partners and parents than men of lower genetic quality, women may profit from securing a stable investment from the latter, while obtaining good genes via extrapair mating with the former. Only if conception occurs, however, do the evolutionary benefits of such a strategy overcome its costs. Accordingly, we predicted that (a) partnered women should prefer attached men, because such men are more likely than single men to have pair-bonding qualities, and hence to be good replacement partners, and (b) this inclination should reverse when fertility rises, because attached men are less available for impromptu sex than single men. In this study, 208 women rated the attractiveness of men described as single or attached. As predicted, partnered women favored attached men at the low-fertility phases of the menstrual cycle, but preferred single men (if masculine, i.e., advertising good genetic quality) when conception risk was high.


  1. The evolutionary psychology approach might be dubious, but the results seem robust and quite counterintuitive. An alternative explanation (especially a non-evolutionary one) doesn't come to mind easily, don't you think?
    Great blog, by the way.

  2. Anonymous1:00 PM

    I do not understand why more masculine men would have better genes. This way of thinking is too much simplified.

  3. Dear Anonymous: there are costs involved in developing masculine traits. The reason is that they require high testosterone levels. Testosterone decreases the effectiveness of the body's immune system, hence only healthy individuals with so-called "good genes" (basically, a lower load of mutations and a higher resistence to infections and parasites) can afford to produce masculine traits. (At least, so goes the theory!)