Having an imperfect body may come with some substantial benefits, according to a new article in the December issue of Current Anthropology.
The hormones that make women physically stronger, more competitive and better able to deal with stress also tend to redistribute fat from the hips to the waist, according to Elizabeth Cashdan, an anthropologist at the University of Utah. So in societies and situations where women are under pressure to procure resources, they may be less likely to have the classic hourglass figure.
Cashdan’s hypothesis aims to explain a peculiar observation. Women around the world tend to have larger waist-to-hip ratios—more cylindrical rather than hourglass-shaped bodies—than is considered optimal.
Medical studies have shown that a curvy waist-to-hip ratio of 0.7 or lower is associated with higher fertility and lower rates of chronic disease. Studies have also shown that men prefer a ratio of 0.7 or lower when looking for a mate. The preference makes perfect sense, according to evolutionary psychologists, because the low ratio is a reliable signal of a healthy, fertile woman.
But in data that Cashdan compiled from 33 non-Western populations and four European populations, the average waist-to-hip ratio for women is above 0.8. If 0.7 is the magic number both in terms of health and male mate choice, why are most women significantly higher?
That’s where the hormones come in.
Androgens, a class of hormones that includes testosterone, increase waist-to-hip ratios in women by increasing visceral fat, which is carried around the waist. But on the upside, increased androgen levels are also associated with increased strength, stamina, and competitiveness. Cortisol, a hormone that helps the body deal with stressful situations, also increases fat carried around the waist.
“The hormonal profile associated with high WHR (waist-to-hip ratio) … may favor success in resource competition, particularly under stressful circumstances,” writes Cashdan. “The androgenic effects—stamina, initiative, risk-proneness, assertiveness, dominance—should be particularly useful where a woman must depend on her own resources to support herself and her family.”
In other words, trading the benefits of a thin waist for better ability to collect resources may be a good deal in certain societies and situations. And there is evidence that male mate preferences may reflect this trade-off, according to Cashdan.
In Japan, Greece and Portugal, where women tend to be less economically independent, men place a higher value on a thin waist than men in Britain or Denmark, where there tends to be more sexual equality. And in some non-Western societies where food is scarce and women bear the responsibility for finding it, men actually prefer larger waist-to-hip ratios.
“Waist-to-hip ratio may indeed be a useful signal to men, then, but whether men prefer a WHR associated with lower or higher androgen/estrogen ratios (or value them equally) should depend on the degree to which they want their mates to be strong, tough, economically successful and politically competitive,” Cashdan writes.
“And from a woman's perspective, men's preferences are not the only thing that matters.”
Cashdan, Elizabeth, “Waist-to-hip Rations Across Cultures: Trade-offs Between Androgen- and Estrogen-Dependent Traits,” Current Anthropology 49:6, December 2008
Sponsored by the Wenner-Gren Foundation for Anthropological Research, Current Anthropology is a transnational journal devoted to research on humankind, encompassing the full range of anthropological scholarship on human cultures and on the human and other primate species. Communicating across the subfields, the journal features papers in a wide variety of areas, including social, cultural, and physical anthropology as well as ethnology and ethnohistory, archaeology and prehistory, folklore, and linguistics.Contacts:
-- Kevin Stacey, publicity manager, University of Chicago Press – (773) 834-0386 / firstname.lastname@example.org
Lee Siegel | Newswise Science News
Europe’s Demographic Future. Where the Regions Are Heading after a Decade of Crises
10.08.2017 | Berlin-Institut für Bevölkerung und Entwicklung
Scientists reveal source of human heartbeat in 3-D
07.08.2017 | University of Manchester
Whether you call it effervescent, fizzy, or sparkling, carbonated water is making a comeback as a beverage. Aside from quenching thirst, researchers at the University of Illinois at Urbana-Champaign have discovered a new use for these "bubbly" concoctions that will have major impact on the manufacturer of the world's thinnest, flattest, and one most useful materials -- graphene.
As graphene's popularity grows as an advanced "wonder" material, the speed and quality at which it can be manufactured will be paramount. With that in mind,...
Physicists at the University of Bonn have managed to create optical hollows and more complex patterns into which the light of a Bose-Einstein condensate flows. The creation of such highly low-loss structures for light is a prerequisite for complex light circuits, such as for quantum information processing for a new generation of computers. The researchers are now presenting their results in the journal Nature Photonics.
Light particles (photons) occur as tiny, indivisible portions. Many thousands of these light portions can be merged to form a single super-photon if they are...
For the first time, scientists have shown that circular RNA is linked to brain function. When a RNA molecule called Cdr1as was deleted from the genome of mice, the animals had problems filtering out unnecessary information – like patients suffering from neuropsychiatric disorders.
While hundreds of circular RNAs (circRNAs) are abundant in mammalian brains, one big question has remained unanswered: What are they actually good for? In the...
An experimental small satellite has successfully collected and delivered data on a key measurement for predicting changes in Earth's climate.
The Radiometer Assessment using Vertically Aligned Nanotubes (RAVAN) CubeSat was launched into low-Earth orbit on Nov. 11, 2016, in order to test new...
A study led by scientists of the Max Planck Institute for the Structure and Dynamics of Matter (MPSD) at the Center for Free-Electron Laser Science in Hamburg presents evidence of the coexistence of superconductivity and “charge-density-waves” in compounds of the poorly-studied family of bismuthates. This observation opens up new perspectives for a deeper understanding of the phenomenon of high-temperature superconductivity, a topic which is at the core of condensed matter research since more than 30 years. The paper by Nicoletti et al has been published in the PNAS.
Since the beginning of the 20th century, superconductivity had been observed in some metals at temperatures only a few degrees above the absolute zero (minus...
16.08.2017 | Event News
04.08.2017 | Event News
26.07.2017 | Event News
22.08.2017 | Health and Medicine
22.08.2017 | Materials Sciences
22.08.2017 | Life Sciences