Abstract:
This paper examines the role of body fat distribution as measured by waist-to-hip ratio (WHR) on the judgment of women's physical attractiveness. It presents evidence that WHR is correlated with a woman's reproductive endocrinological status and long-term health risk. Three studies were conducted to investigate whether humans have perceptual and cognitive mechanisms to utilize the WHR to infer attributes of women's health, youthfulness, attractiveness, and reproductive capacity. Collegeage as well as older subjects of both sexes rank female figures with normal weight and low WHR as attractive and assign to them higher reproductive capability. The study concludes that WHR is a reliable and honest signal of a woman's reproductive potential. The adaptive significance of body fat distribution and its role in mate selection is also discussed.

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Introduction: All theories of human mate selection based on evolutionary principles assume that attractiveness provides a reliable cue to a woman's reproductive value and success. Consistent with this assumption is that men assign far greater signifi-cance to a woman's "good looks" than women do to men , and this appears to be a cross-cultural universal.
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But what constitutes "good looks"? Cross-cultural data provide a bewildering array of what various societies consider beautiful: depressed and elongated foreheads, bound feet, perforated lips, blackened teeth, and embossed skin contrast sharply with American preferences. Many observers, from social scientists to laymen, have therefore reasoned that beauty must be culturally conditioned.
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The belief in the capriciousness of standards of attractiveness has prevented any systematic search for exploring bodily features that are universally perceived as attractive because they signal women's reproductive potential. Various ethnic groups differ on many morphological features, such as color of the skin and hair, shape of the nose, eyes, and lips, etc. Culturally determined features, such as hair style and face or skin alteration with the help of paint or other cosmetic devices, accentuate these differences. The acquired features, ranging from clothing and ornamentation to scarification and tattooing, presumably serve to identify group membership and social status.
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If there is indeed an adaptive significance to female attractiveness it is probably conveyed by secondary sex characteristics. The total amount of body fat and its distribution maximally differentiates male and female body shape and may play a central role in judging female attractiveness. In this paper I will first summarize evidence demonstrating that body fat distribution has links to proximate physiological mechanisms regulating health, fecundity, and capacity to sustain pregnancy and lactation. I will then show that body fat distribution plays an important role in perceived attractiveness, health, and reproductive capability of women.
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WHR and Physical Attractiveness:
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It would follow that men who sought and mated with women with gynoid fat distribution would leave more progeny than men who mated indiscriminantly. The greater reproductive success of these females would maximize their contribution to the gene pool of future generations. Over time, men would have favored women with gynoid figures. Because our species is relatively hairless, even a small increase in subcutaneous fat and superficial fat depots (buttocks and breasts) would highlight a gynoid figure. Conceived in this manner, gynoid fat distribution and its measure, WHR, become attractive because of their invariant relationship with the concealed reproductive value of the female.
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An additional advantage of gynoid fat is that it not only accurately signals the woman's reproductive potential, it is also orientation-independent: it remains constant whether viewed from front, behind, or side. The degree of "femininity" can be easily and accurately assessed by viewing a woman from the back. Although some investigators have proposed that breasts signal a woman's reproductive value, and others have suggested that the breasts evolved to mimic buttocks, breasts do not accurately reflect the reproductive capability of women.
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WHR appears to be the most accurate signal of female reproductive capability. It could be this factor that magnifies the sexual attractiveness of an "hourglass figure": shapely breasts and broad hips set against a narrow waist. In the same vein, pregnancy alters the waist more dramatically. Thus a high WHR may mimic pregnancy and render women less sexually attractive.
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Obviously, men do not select their consorts on the basis of WHR alone. A multitude of other factors, such as facial characteristics, culturally defined physical alterations, personality attributes, and socioeconomic status, influence the choice of the mate. However, the linkage between the WHR and reproductive success suggests that the WHR could act as a wide first-pass filter in initial selection of the potential mate. If valid, this hypothesis would suggest that diverse notions of what constitutes attractiveness should be found only in bodily features (stature, degree of plumpness, strong legs or arms, etc.), facial characteristics (color, shape of eyelid or lips, etc.), and personality (coyness, sense of humor, submissiveness, etc.); the WHR should be culturally invariant in its significance and its relationship to female attractiveness. A corollary to this suggestion would be that women in most societies would not attempt to modify their WHR (except to make it look lower) to enhance their physical attractiveness. Standardized cross-cultural studies would be needed to evaluate the validity of these suggestions.   • • •