Scientists from Michigan State University have challenged the theory that women are pressured into idolising the look of size-zero celebrities, the Daily Express reported.
Researchers assessed more than 300 identical and non-identical female twins between the ages of 12 and 22 on their attitudes to being thin.
They found that identical twins, sharing 100 per cent of their genes, had closer levels of 'thin internalisation' than fraternal twins, who share only 50 per cent. This indicated a significant role for genetics.
"We're all bombarded daily with messages extolling the virtues of being thin, yet intriguingly only some women develop what we term 'thin ideal internalisation'. This suggests that genetic factors may make some women more susceptible to this pressure than others," researchers said.
"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," lead researcher Jessica Suisman, said.
The study was published in the International Journal of Eating Disorders.