Modern culture has an image of what ideal beauty looks like in a woman. Ads demonstrate a longing to be thin, tall and curvy at all once, and some of our favorite idols demonstrate our love for large backsides. While most of this may seem arbitrary, scientists say that, in fact, having big buttocks may actually come with benefits. According to a study published in the journal Evolution and Human Behavior, women with a large waist-to-hip ratio tend to have smarter babies than women with a smaller ratio. The reason? Fat stored in the hip region goes toward building an infant's brain.
The curvy mystery
Scientists have long wondered why women develop curvier bodies with more fat than men. Researchers from the University of Pittsburgh and the University of California, Santa Barbara, studied more than 16,000 women of all ages and ethnicities to see how their fat levels impacted their children. The results indicated that women with a high WHR have more energy stores and fat to devote to fetal development, particularly neurodevelopment. What's more, the fat stored in women's hips, thighs and buttocks enters breast milk and provides nutrients for babies' brains during feedings. As such, the more fat a woman has near her hips, the higher her baby's IQ is likely to be.
On the flip side, women with high WHR tend to have lower cognitive abilities than women with low WHR. As such, women with smaller hips are often more intelligent than women with more fat, but the latter group produces smarter children.
The right fat
The study noted that while WHR impacts intelligence in women, body mass index does not. Fat in regions outside of the hip and backside area does not aid in child cognitive development. The fat surrounding the buttocks and hips – near the uterus – does benefit children.
"The fat in these areas is a depot for building a baby's brain," William Lassek, professor at the University of Pittsburgh, study author and co-author of the book "Why Women Need Fat," told the Daily Mail. "You need lots of fat to make a nervous system, and the fats in these areas are also enriched in DHA (docosahexaenoic acid), which is a particularly important component in the human brain. It looks as if women have evolved to accumulate these fats and hold on to them – until a baby arrives."
Researchers also said that modern women may have more fat than their ancient counterparts in order to supply more nutrients to the demanding needs of today's intelligent humans.