Reason Why Men Love Curvy Spines And Fleshy Butts Revealed

Right now it's women's backsides that are breaking the Internet. The female form is interesting, of course. Earlier research showed that men preferred women who had smaller waists than hips---which indicated youth as well as fertility.

But a new study says that there is an evolutionary theory behind men's interest in backsides, especially in the curved spines of women.

"Over the course of human history, women faced the adaptive problem of a forwarded-shifted center of mass during pregnancy," said study co-author Eric Russell, a graduate student in psychology at the University of Texas at Arlington, according to The Huffington Post. "Women with a greater degree of lumbar curvature ... were able to redistribute this center of mass to reduce the strain of pregnancy. Thus, we hypothesized that men should have a psychological adaptation to prefer these women as mating partners."

It explains why voluptuous celebrities such as Kim Kardashian and Jennifer Lopez seem so attractive, even as extra flesh around their butts increased the spine's curvature, according to dailymail.co.

Hence, men's inclination for this specific anatomical form has evolved as it helped women to "sustain multiple pregnancies without injury and to forage productively during pregnancy."

The study was enabled by studying more than 300 men, who judged the attractiveness of female silhouettes with lumbar curvatures that ranged from 26 to 61 degrees.

The study enabled men to identify a moderate curvature of about 45.5 degrees, that equipped "evolutionary advantages" but without leading to health problems such as back pain and slipped disks, according to the researchers.

Scientists say that it is the structure of the spine rather than merely the fat and muscle power on the buttocks that is important.

"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," Dr. David Lewis, a psychologist at Bilkent University in Turkey and the study's lead author, told the Daily Mail. "Alternatively, men may have preferences for both lumbar curvature and buttock size. Future research is needed to better understand the latter."

The study was published online on February 7 in the journal Evolution and Human Behavior.