Letters to the Editors; February 1996; Scientific American Magazine; by Staff Editor; 1 Page(s)

I was disappointed that John Horgan, in his article "The New Social Darwinists" [SCIENTIFIC AMERICAN, October 1995], appears to share Scientific American's long-standing inability to look at human sociobiology objectively. His worst lapse comes at the very beginning. Devendra Singh has helped isolate a major variable in the attribution of human attractiveness, the waist-hip ratio. Throughout the range of female human shapes, increasing waist-to-hip ratios are associated with increasing mortality, decreasing fertility, increasing free testosterone levels and decreasing attractiveness. But Horgan goes for the cheap laughs and misses all the content. His article reveals a recurring problem serious scientists have on the subject of human behavior.

I would like to propose an evolutionary explanation for why "gentlemen prefer blondes" over brunettes in Western cultures. Several authors have suggested that florid displays of secondary sexual characteristics "inform" the female that the suitor is healthy and free of dermal parasites. I suggest that being blonde serves a similar purpose. Anemia (a common symptom of intestinal parasites), cyanosis, jaundice and skin infection are much easier to detect in fair-skinned individuals than in brunettes. Also, the skin of blondes "ages" faster and more visibly than that of brunettes. Fertility in women declines with age and with disease, so men may gravitate toward blondes, in whom such signs are easier to observe. I originally intended the above as a parody of ad hoc sociobiological theories of human mate selection but came to realize that this idea is at least as viable as many others currently in vogue, including those mentioned by Horgan.