The study involved men who had been sightless from birth. The idea was that the bombardment of visual media — of models on billboards and actresses on television and porn stars online — which may be so powerful and even dominant in molding desire, couldn’t have had any direct effect on these men, who emerged from the womb into a congenital dark. Would their tastes in women’s bodies match those of men who could see? How would their preferences reflect on the roles of nature and nurture, on the influence of evolution and the impact of experience, in forming our psyches?

Image Credit... Carla van de Puttelaar

More than a century ago, Sigmund Freud placed sex at the foundation of psychology; erotic desire was the fundamental element of the self. Psychiatric researchers have long since tended to distance themselves from much of his thinking, yet few would deny the libido’s crucial part in who we are, with its neural systems radiating outward from the primal regions of the brain. So the studies of sexologists like Karremans, no matter how far-fetched or even bizarre they may sometimes seem — hot mannequins and blind men! — are often an attempt not only to parse the erotic but also to begin to understand the way our very beings are constructed.

Over the past two decades, researchers have been looking at whether cinched yet sumptuous female body shapes, corresponding to low waist-to-hip ratios, are preferred by men across societies and have been favored across time, the idea being that if the answer is yes, evolutionary factors would seem to outweigh culture in determining at least this one aspect of lust. And frequently when scientists have shown simple line drawings of women to men around the world, from Germany to Japan to Guinea-Bissau, the answer has in fact been yes; ratios of 0.7, or sometimes lower, have been rated the most attractive, no matter whether more or less overall flesh is the cultural ideal. A study of Miss Americas from the 1920s to the ’80s and of Playboy centerfolds from the ’50s to 1990 came up with the same result; the chosen women became thinner over the decades, but their proportions stayed constant, right around 0.7. The evolutionary explanations for these findings share the logic that lower ratios somehow signaled ancestral men that a woman would produce more or fitter offspring, and the argument of one recent study, built on data from several thousand women and children, is that mothers with lower ratios tend to produce smarter kids, because, the researchers suggest after controlling for other factors, certain fatty acids in a woman’s hip padding, delivered in the womb and through breast-feeding, are beneficial to the development of a baby’s brain, while belly fat is detrimental.

Yet the Miss America and centerfold findings have been criticized for flawed statistics; a study of the nudes celebrated by the 17th-century Flemish painter Peter Paul Rubens documented W.H.R.’s a good deal higher than 0.7; and research among isolated hunter-gatherers in Tanzania and the primitive Matsigenka people in a remote rain-forest territory of Peru has countered the idea of cross-cultural consistency. In Peru, within a vast park whose core serves as a kind of societal preserve, because outsiders are almost completely barred, a pair of scientists with line drawings discovered that Matsigenka men don’t favor women with lower W.H.R.’s at all. Among a Matsigenka group living just outside the park and within reach of Western media and modernity, meanwhile, the researchers reported tastes in female forms to be more similar to those of Western men, and in a nearby area, among a tribally mixed population with yet more Western contact, male preferences were no different from those in the West. Culture, in this study, appeared to mold the shape of lust.

Amid all the conflicting evidence, Karremans sent his mannequins around the Netherlands. The blind stood before them; they were told to touch the women, to focus their hands on the waists and hips. The breasts on both figures were the same, in case the men reached too high. The men extended their arms; they ran their hands over the region. Then they scored the attractiveness of the bodies. Karremans had a hunch, he told me, that their ratings wouldn’t match those of the sighted men he used as controls, half of them blindfolded so that they, too, would be judging by feel. It seemed likely, he said, that visual culture would play an overwhelming part in creating the outlines of lust. And though the blind had almost surely grown up hearing attractiveness described, perhaps even in terms of hourglass shapes, it was improbable, he writes in his forthcoming journal paper, that they had heard descriptions amounting to, “The more hourglass shaped, the more attractive,” which would be necessary to favor the curvier mannequin over the figure that was only somewhat less so.