Women are more likely to be bisexual than men, a study has found.
The poll of more than 9,000 young adults found that females were also more likely to choose the label 'mostly heterosexual'. They were also more likely to change their mind about their sexuality. In contrast, males tended to describe themselves as '100 per cent heterosexual' or '100 per cent homosexual'.
Researcher Elizabeth McClintock, of the University of Notre Dame in Indiana, said: 'This indicates that women's sexuality may be more flexible and adaptive than men's.' Her study comes as growing numbers of female celebrities openly talk about being bisexual.
Hollywood actresses Angelina Jolie had a love affair with Japanese-American model Jenny Shimizu. Jolie, who now has six children with actor Brad Pitt, once said that, in different circumstances, she would 'probably have married Jenny'. Supermodel Cara Delevingne has insisted her bisexuality is not a phase and actress Amber Heard had a long-term relationship with a female photographer before marrying Johnny Depp.
Dr McClintock analyzed the results of a US study in which more than 5,000 women and 4,000 men were quizzed on their sexuality three times as between their teens and their late 20s. On average, they were 16 years old when first polled, 22 when spoken to the second time, and 28 when they give their final set of answers.
Questions included whether they would describe themselves as '100 per cent heterosexual', 'mostly heterosexual', 'bisexual', 'mostly homosexual' or '100 per cent homosexual'. The women were more likely than the men to call themselves bisexual. They were also three times more likely to change their minds about their sexuality in their 20s, the American Sociological Association's annual conference heard.
Dr McClintock said that 'male eroticization' of the topic allows women to experiment by, for instance, kissing other females at parties, without being stigmatized.
And while women don't choose to find to be bisexual, their circumstances can affect their affections. For instance, her analysis showed that attractive women were more likely to think of themselves as purely heterosexual.
Dr McClintock said that women may be less likely to experiment with bisexuality when they find it particularly easy to find a male partner. However, women with the same sexual attractions, but less favorable heterosexual options may have greater opportunity to experiment with same-sex partners.
The study also found that young mums often thought of themselves as being heterosexual in their early 20s, only to lean towards bisexuality a few years later. Men in contrast, tend to be more set in their ways.
The researcher said: 'Men are less often attracted to both sexes. Men's sexuality is, in a sense, less flexible. If a man is only attracted to one sex, romantic opportunity would little alter his sexual identity.'