(PhysOrg.com) -- It has long been known that men find an "hourglass" figure the most attractive shape for the female body, and now scientists have found out why.
Research across a variety of cultures has demonstrated that men typically find the curvaceous female form sexually attractive. Other studies have shown that wide hips in women are associated with health and reproductive potential, so the attraction makes evolutionary sense.
Scientists from Georgia Gwinnett College in Lawrenceville, Georgia, studied the responses of 14 men with an average age of 25 to nude photographs of women before and after undergoing cosmetic surgery that redistributed fat from their waists to the buttocks to give them more of an hourglass figure. The operations did not reduce the weight of the women, but gave them an “optimal” Waist to Hip Ratio (WHR) of about 0.7.
The fMRI brain scans of the male subjects showed the post-surgery pictures activated the same regions of the brain that are activated by rewards, alcohol and drugs. Changes to women’s body mass index (BMI) did not affect the reward centers, but instead activated brain areas associated with the visual recognition of shape and size. This suggests judgments of female attractiveness based on body fat are based on society expectations rather than being hard-wired in the brain.
Steven Platek, an evolutionary cognitive neuroscientist, said the research may help explain why some men are addicted to pornography, and may also shed some light on other disorders “such as erectile dysfunction in the absence of pornography,” and add to our study of sexual infidelity. It also helps explain phenomena such as sexual harassment and whistling at curvaceous girls in the street. Platek said the BMI results suggest the female form projected by the media, of skinny waif-like models, is not the most attractive to men, and curves are worth their reproductive weight in gold.
The research paper, by Platek and Devendra Singh, presents the first description of the effect of WHR on men’s brains. It was published online in PLoS One on February 5.
Explore further: Epilepsy drugs may cause sexual disorders