Free Why Beautiful People Have More Daughters: From Dating, Shopping, and Praying to Going to War and Becoming a Billionaire–Two Evolutionary Psychologists Explain Why We Do What We Do by Alan S. Miller, Satoshi Kanazawa Page A

you look at her face and her entire body, because the condition of her hair is usually a very accurate indicator of her age. You’ve now discovered the importance of hair as an indicator of age in the ancestral environment.
    Small Waist
    Why are 36–24–36 considered the ideal female measurements? It turns out that these numbers are not chosen arbitrarily.
    An evolutionary psychologist at the University of Texas, Devendra Singh, conducted experiments in different societies to demonstrate that men have a universal preference for low waist-to-hip ratio (the waist measurement divided by the hip measurement). Presented with figure drawings of women identical in every way except the waist-to-hip ratio (varying from 0.7 to 1.0), most men in Singh’s experiments expressed preference for women with the waist-to-hip ratio of 0.7, which is very close to the waist-to-hip ratio of anyone with the 36–24–36 measurements (0.67). 8 One of us (Kanazawa) has informally replicated Singh’s experiments in three different countries on three different continents (the US, New Zealand, and the UK) and found the same results as Singh. Most men prefer women with a 0.7 waist-to-hip ratio, and most women prefer men with a 0.9 waist-to-hip ratio.
    Why, then, do men want women with low waist-to-hip ratios? Singh argues that this is because healthy women have lower waist-to-hip ratios than unhealthy women. A host of diseases—such as diabetes, hypertension, heart attack, stroke, and gallbladder disorders—change the distribution of body fat so that sickly women cannot maintain low waist-to-hip ratios. Women with low waist-to-hip ratios are also more fertile; they have an easier time conceiving a child and do so at earlier ages because they have larger amounts of essential reproductive hormones. 9 And, of course, women who are already pregnant with another man’s child cannot maintain a low waist-to-hip ratio.
    The female waist-to-hip ratio also fluctuates, albeit very slightly, over the menstrual cycle; it becomes lowest during ovulation, when the woman is fertile. 10 Thus, men are unconsciously seeking healthier and more fertile women when they seek women with small waists.
    The preference for a low waist-to-hip ratio, identified by Singh, explains both the popularity of corsets in many Western societies throughout history as a device to make women’s waists appear as small as possible, and the current trend of young women to bare their midriffs. It also explains why it is teenage girls, not menopausal women, who are more likely to bare their midriffs as an honest signal of their high fecundity (the ability to conceive), just like it is young women, not old women, who grow their hair long as an honest signal of their health. Once again, the superstardom of Britney Spears was not the cause of young girls’ desire to show their midriffs; rather, it is a consequence of it.
    Large Breasts
    Why men prefer women with large breasts had long been a mystery in evolutionary psychology, especially since the size of a woman’s breasts has no relationship with her ability to lactate; women with small breasts can produce as much milk for their infants as those with large breasts. 11 So women with large breasts do not necessarily make better mothers than women with small breasts. Why, then, do men prefer women with large breasts? There was no satisfactory answer to this question until recently.
    The then Harvard anthropologist Frank Marlowe suggested a solution to this puzzle in the late 1990s, 12 although with hindsight it is another mystery why nobody else thought of the idea sooner. Marlowe makes the simple observation that larger, and hence heavier, breasts sag more conspicuously with age than do smaller breasts. Thus, it is much easier for men to judge a woman’s age (and her reproductive value) by sight if she has larger breasts than if she has smaller breasts, which do not change as much with age. Recall