Genetic influences, plus our social
environment, could put some at risk.
Reprinted from Eating Disorders Review
November/December 2012 Volume 23, Number 6
©2012 Gürze Books
A recent study of twins has shown that genetic makeup may make some women more vulnerable than others to social pressures to be thin. As Jessica Suisman, MD, and coworkers at Michigan State University recently reported (Int J Eat Disord 2012 Oct 3.doi: 10.1002/eat.22056.[Epub ahead of print]), among 343 post-pubertal female twins (ages: 12-22 years), in the Michigan Twin Registry, twin modeling suggested significant additive genetic and nonshared environmental influences on thin-ideal internalization.
The team from Michigan State measured how much participants wanted to look like movie stars and other celebrities. Once the levels of thin idealization had been established, identical twins-who share 100% of their genes-were compared with fraternal twins, who share 50% of their genes.
Dr. Suisman and colleagues found that identical twins had closer levels of thin idealization than did the fraternal twins, which suggested a role for genetic contributions to this phenomenon. One surprise was that shared environmental factors, such as exposure to the same media, did not have as large an impact as had been expected. Dr. Suisman noted that non-shared environmental include typical experiences that twins do not share, such as sports, dance, or one twin being exposed to more media that promote thinness or one of the twins having a circle of friends who place undue importance on being thin.
