Bisexuality in women appears to be a distinctive sexual orientation and not an experimental or transitional stage that some women adopt "on their way" to lesbianism, according to new research published by the American Psychological Association.

The study of 79 non-heterosexual women over 10 years found that bisexual women maintained a stable pattern of attraction to both sexes. In addition, the research appears to have debunked the stereotype that bisexual women are uninterested in or unable to commit to long-term monogamous relationships.

"This research provides the first empirical examination of competing assumptions about the nature of bisexuality, both as a sexual identity label and as a pattern of nonexclusive sexual attraction and behavior," wrote University of Utah psychologist Lisa M. Diamond, PhD, who conducted the study. "The findings demonstrate considerable fluidity in bisexual, unlabeled and lesbian women's attractions, behaviors and identities and contribute to researchers' understanding of the complexity of sexual-minority development over the life span."

Results of the research were published in the January issue of Developmental Psychology, published by the APA. This special issue of the journal focuses on research into psychological topics concerning sexual orientation and gender identity.

Diamond used interview data collected five times over a decade from 79 women who identified as lesbian, bisexual or unlabeled. The subjects firstly ranged in age from 18 to 25 years old.

Among Diamond's findings:

• Seventeen percent of respondents switched from a bisexual or unlabeled identity to heterosexual during the study -- but more than half of these women switched back to bisexual or unlabeled by the end.
• Women's definitions of lesbianism appeared to allow more flexibility in behavior than their definitions of heterosexuality. For instance, of the women who identified as lesbian in the last round of interviews, 15 percent reported having sexual contact with a man during the preceding 2 years. In contrast, none of the women who settled on a heterosexual label at that point reported having sexual contact with a woman within the preceding 2 years.
• Bisexual and unlabeled women were more likely than lesbians to change their identity over the course of the study, but they tended to switch between bisexual and unlabeled rather than to settle on lesbian or heterosexual as their identities.
• By year 10, most of the women were involved in long-term (i.e., more than a year in length) monogamous relationships -- 70 percent of the self-identified lesbians, 89 percent of the bisexuals, 85 percent of the unlabeled women and 67 percent of those who were then calling themselves heterosexual.

"This provides further support for the notion that female sexuality is relatively fluid and that the distinction between lesbian and bisexual women is not a rigid one," Diamond wrote.

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