In this recent trial, experts keyed in on possible psychological effects of women giving into the societal view of being "skinny".
When women start to change the way they feel about themselves and their bodies and begin to change their behavior in order to get to an ideal weight, it leads to over-obsessiveness about appearance, a key element of eating disorders.
Lead author of the study, Jessica Suisman from Michigan State University (MSU), commented:
"We're all bombarded daily with messages extoling the virtues of being thin, yet intriguingly only some women develop what we term thin ideal internalization. This suggests that genetic factors may make some women more susceptible to this pressure than others."
To determine whether women give into the pressure placed by society to be thin, the authors examined the "idealization of thinness" in more than 300 sets of female twins aged 12 to 22. All of the participants were from the MSU Twin Registry.
The twins were asked how strong their desires were to resemble people they had seen on television, in movies and in magazines. After analyzing their responses, the researchers compared fraternal twins (50% of the same genes) to identical twins (100% of the same genes).
Findings revealed that identical twins' levels of thin idealization were closer than those in the fraternal twins, which means that the girls' genetics probably played a large part in their answers.
Upon further investigation, they found that 43% of thin idealization is inherited, which meant that almost half of the reason why women all look at ideal weight differently is because of their genes.
Evidence from the study also showed that environmental influences alter a woman's thin idealization as well. Twins' thin idealization was shaped more because of environmental factors than vast cultural attitudes, which women from Western civilizations are exposed to.
"We were surprised to find that shared environmental factors, such as exposure to the same media, did not have as big impact as expected. Instead, non-shared factors that make co-twins different from each other has the greatest impact," said Suisman.
The study did not focus on particular environmental triggers, including experiences the twins did not share.
Suisman continued, "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, a professor of psychology at MSU and co-author of the study, said it is well known that many different elements can lead to girls developing eating disorders. A study published in April of this year said that eating disorders could be caused by lack of support following a traumatic event.
"This study reveals the need to take a similar approach to the ways in which women buy in to pressure to be thin, by considering how both genetic and environmental factors contribute to the development of thin-ideal internalization."
Written by Christine Kearney