When it comes to men’s preferences in women’s bodies, some along with Sir Mix-a-Lot have illustrated their preference for bigger buttocks over the years. But studies done by The University of Texas at Austin and published online in Evolution and Human Behaviour suggest a new angle to be taken towards standards of beauty. Indicating that this preference may be more due to the curve that crosses over from the back to the buttocks.
This curve, called the “lumbar curvature” (as pictured to the left) has a theoretically optimal angle at around 45.5 degrees. The preference has prehistoric influences as it allowed ancestral women to better support, provide for, and carry out multiple pregnancies along with limiting the risk of spinal injuries.
Beauty may not be in the eye of the beholder
“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 David Buss, a UT Austin psychology professor and the study’s co-author. “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.”
The research lead by an Austin alumnus and Bilkent University psychologist David Lewis, consisted of two studies. The first one investigated the wedging of the spinal vertebrae, the underlying characteristic that can influence the actual curve of a woman’s lower back. Around 100 men rated the attractiveness of several images that displayed a spectrum of spinal curves that occur naturally. The result was that the men found the images displaying women with the theoretical optimum of 45 degrees of lumbar curvature, as the most attractive.
In the second study they evaluated whether the angle was preferred for emphasizing larger buttocks or whether it really was the angle of the spine itself. Around 200 men were then showed groups of images with different buttock sizes and wedging of the vertebrae that still maintained the 45 degree curve. Here the men consistently preferred the women with a curvature closer to the optimum regardless of buttock size.
Evolutionary pressures have influenced us more than we may think
“This enabled us to conclusively show that men prefer women who exhibit specific angles of spinal curvature over buttock mass,” said a researcher and the study’s co-author Eric Russell from UT Arlington. This preference, having evolved over thousands of years 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.