A recent study has presented yet another explanation for why many men prefer women with curvy backsides. The study found that evolution has preferred women with a spine curvature of 45 degrees because it allowed them to remain mobile throughout pregnancy without risk of injuring themselves. Researchers believe this finding may partially explain why modern man remains so infatuated with this feature in potential female partners.

The Importance Of Spine Curvature

The curve at the bottom of a woman’s spine is something that she wouldn’t realize the importance of until it’s gone. A spinal curve allows women to significantly shift their weight, and without this ability, pregnant women would face a serious disadvantage. According to the study, without a spine curvature of this degree the pressure on a woman’s hips during pregnancy would increase by 800 percent. This would cause her to not only become largely immobile, but also put her at risk for sustaining serious injury.

“[The curve] would have enabled ancestral women to shift their center of mass back over their hips during pregnancy, a time during which there is a dramatic forward shift of their center of mass,” said lead researcher Dr. David Lewis, The Daily Mail reported.

It’s believed that our male ancestors developed a sexual attraction to women with this physical trait because it increased their chances of having offspring which would live long enough to pass on their DNA.

It’s not just ancient men who show a preference for women with this build, however. The team, based out of Bilkent University in Turkey, asked 300 men to look at silhouettes of women with many different angles of spine curvature. Results showed that the majority of the men were significantly more attracted to silhouettes of women who had a spine curvature of 45.5 degrees, suggesting that this ancestral preference for spinal curvature has persisted.

Lewis believes that his findings may offer an explanation into modern man’s love of round female butts.

“Men may be directing their attention to the butt and obtaining information about women's spines, even if they are unaware that that is what their minds are doing,” the researcher explained, although this theory cannot be proven until future research is conducted.

Our Love Of Big Butts

This is not the first time science has attempted to find a reason for evolutionary preference of round-bottomed women. A 2014 study found that women with larger waist-to-hip ratios had higher levels of the hormone needed to get pregnant, and therefore possessed increased chances of fertility. Another study found an association between large bottoms and intelligence, presenting evidence that women with a bigger difference between their hips and waist were not only more intelligent themselves, but also gave birth to more intelligent children.

Ultimately, human attraction is a complicated topic, and what appeals to some does nothing for others. However, when we find out the science behind our preferences, we can’t help but wonder if our “type” is really a personal choice or simply nature’s way of ensuring the advancement of mankind.

Source: Lewis DMG, Russell EM, Al-Shawaf L, Buss DM. Lumbar curvature: a previously undiscovered standard of attractiveness. Evolution and Human Behavior. 2015.