It's not always media: Genes make women want to be thin
Researchers say some women’s desire to be thin might be driven by genes. The finding, published October 3, 2012, comes from a study of twins that shows some women are more susceptible to a desire to be skinny that has little to do with media influences.
Though environmental influences such as magazines, TV and movies do play some role in a woman’s desire to be skinny, Jessica Suisman, lead author on the study and a researcher in the Michigan State University (MSU) Department of Psychology explains not all women ‘buy in’ to media pressure to be thin.
"This suggests that genetic factors may make some women more susceptible to this pressure than others”, Suisman said in a press release.
She explains that daily bombardment with “… messages extoling the virtues of being thin lead just ‘some’ women to develop what is called thin-ideal internalization.”
Suisman and her colleagues wanted to see just what role Western culture and other external factors have on a woman’s body image.
For their study, published in the International Journal of Eating Disorders, the researchers looked at more than 300 female twins from the MSU Twin Registry, ages 12-22.
Suisman and her team measured how much twins wanted to look like people seen on television, in movies and in magazines.
There was a strong desire for thinness among identical twins that share 100% of their genes that wasn’t present with fraternal twins that share just 50% of genes.
The researchers also note that though environment influences some women’s desire to be thin, the impact of media isn’t as great as anticipated. Wanting to be skinny comes from other influences that are unique.
"We were surprised to find that shared environmental factors, such as exposure to the same media, did not have as big an impact as expected," Suisman said. "Instead, non-shared factors that make co-twins different from each other had the greatest impact” – for example friendship groups that place high importance on weight.
"The take-home message," Suisman said, "is that the broad cultural risk factors that we thought were most influential in the development of thin-ideal internalization are not as important as genetic risk and environmental risk factors that are specific and unique to each twin."
Kelly Klump, MSU professor of psychology and co-author on the study said in a press release that’s it’s important to consider both environmental and genetic factors that can influence women and their desire to be skinny.