Jessica Suisman, a research specialist in the department of psychology at Michigan State University, is the lead author of a study that concludes that genetics may explain why some women succumb to societal pressures to be obsessed with being thin.
“We’re all bombarded daily with messages extolling the virtues of being thin, yet intriguingly only some women develop what we term thin-ideal internalization,” said Suisman. “This suggests that genetic factors may make some women more susceptible to this pressure than others.”
More than 300 female twins took part in the study. Suisman and her colleagues measured how much participants wanted to look like people from movies, television, and magazines. Once the levels of thin idealization were assessed, identical twins who share 100 percent of their genes were compared with fraternal twins who share 50 percent.
The results show that identical twins have closer levels of thin idealization than fraternal twins, which suggests a significant role for genetics. The author’s analysis of the data concluded that 43 percent of the difference in the idealization of thinness can be explained by genetic makeup.
The study, funded by a grant from the National Institutes of Health, was published in the International Journal of Eating Disorders.