March 19, 2015 
 
 AUSTIN, Texas — A psychology study from The University of Texas at Austin sheds new light on today’s standards of beauty, attributing modern men’s preferences for women with a curvy backside to prehistoric influences. 
 
 The study, published online in Evolution and Human Behavior, investigated men’s mate preference for women with a “theoretically optimal angle of lumbar curvature,” a 45.5 degree curve from back to buttocks allowing ancestral women to better support, provide for, and carry out multiple pregnancies. 
 
 “What’s fascinating about this research is that it is yet another scientific illustration of a close fit between a sex-differentiated feature of human morphology — in this case lumbar curvature — and an evolved standard of attractiveness,” said the study’s co-author David Buss, a UT Austin psychology professor. “This adds to a growing body of evidence that beauty is not entirely arbitrary, or ‘in the eyes of the beholder’ as many in mainstream social science believed, but rather has a coherent adaptive logic.” 
 
 This research, led by UT Austin alumnus and Bilkent University psychologist David Lewis, consisted of two studies. The first looked at vertebral wedging, an underlying spinal feature that can influence the actual curve in women’s lower backs. 
 
 About 100 men rated the attractiveness of several manipulated images displaying spinal curves ranging across the natural spectrum. Men were most attracted to images of women exhibiting the hypothesized optimum of 45 degrees of lumbar curvature. 
 
 “This spinal structure would have enabled pregnant women to balance their weight over the hips,” Lewis said. “These women would have been more effective at foraging during pregnancy and less likely to suffer spinal injuries. In turn, men who preferred these women would have had mates who were better able to provide for fetus and offspring, and who would have been able to carry out multiple pregnancies without injury.” 
 
 The second study addressed the question of whether men prefer this angle because it reflects larger buttocks, or whether it really can be attributed to the angle in the spine itself. 
 
 Approximately 200 men were presented with groups of images of women with differing buttock size and vertebral wedging, but maintaining a 45.5-degree curve. Men consistently preferred women whose spinal curvature was closer to optimum regardless of buttock size. 
 
 “This enabled us to conclusively show that men prefer women who exhibit specific angles of spinal curvature over buttock mass,” said the study’s co-author Eric Russell, a visiting researcher from UT Arlington. 
 
 This morphology and men’s psychological preference toward it have evolved over thousands of years, and they won’t disappear over night. 
 
 “This tight fit between evolutionary pressures and modern humans’ psychology, including our standards of attractiveness, highlights the usefulness that an evolutionary approach can have for expanding our knowledge not just of the natural sciences, but also the social sciences,” Lewis said. 
 
 For more information, contact: Rachel Griess, College of Liberal Arts, 512-471-2689. ||||| 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.
– A new study finds that there's an evolutionary reason men prefer women with a "theoretically optimal angle of lumbar curvature." Another way of putting it? Even prehistoric guys probably liked a gal with a curvy backside. Researchers at the University of Texas at Austin ran a two-part study, published in Evolution and Human Behavior: In the first part, men rated the attractiveness of manipulated images of spinal curves; most best liked a 45.5-degree curve from back to buttocks. In the second part, men were shown pictures of women with different buttock sizes—and they still most preferred the ones whose spinal curvature was closest to the ideal, meaning it's the lumbar curvature they like, not just "big butts," researchers say in a press release. But "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 lead researcher explains, per Medical Daily. As for that evolutionary reason for the preference, researchers attribute it to "prehistoric influences." Explains the lead researcher, "This spinal structure would have enabled pregnant women to balance their weight over the hips. These women would have been more effective at foraging during pregnancy and less likely to suffer spinal injuries. In turn, men who preferred these women would have had mates who were better able to provide for fetus and offspring, and who would have been able to carry out multiple pregnancies without injury." Researchers note that this preference has evolved over thousands of years. "This adds to a growing body of evidence that beauty is not entirely arbitrary, or 'in the eyes of the beholder,'" says a co-author, "but rather has a coherent adaptive logic." (Another recent study uncovered the surprising reason we hate zits.)