Bisexuality in women could be a lifelong sexual orientation, not a phase, a new study suggests. The finding runs counter to the idea that bisexuality is an experimental or transitional period for women who, for instance, are uncertain or have fear of commitment.
In addition to debunking stereotypes about bisexuality, the research sheds light on the complex nature of sexual orientation in women.
"These findings demonstrate that the distinction between lesbianism and bisexuality is a matter of degree rather than kind," writes University of Utah psychologist Lisa Diamond in the January issue of the journal Developmental Psychology.
To some, a finding of bisexuality as a separate sexual orientation may seem like a no-brainer. But among many scientists and members of the public, bisexuality has been defined by stereotypes and unfounded assumptions.
"There were clearly some theorists who suggested that bisexuality is a transitional stage, but that was largely based on anecdotal, rather than empirical, data," said psychologist M. Paz Galupo, director of LGBT (Lesbian, Gay, Bisexual and Transgender) Studies at Towson University in Maryland. "This view is popularized, also, by the stereotypes that our culture holds regarding bisexual individuals."
Galupo continued: "This notion that bisexuality is just a transition identity has not been challenged much in the research literature, partially because there are only a few researchers investigating sexual orientation who fully take bisexual experience/identity into account."
Galupo, who was not involved in the current research, noted that Diamond's study is one of the first thorough looks at bisexuality using a sort of gold-standard method in which individuals are followed over a long period of time.
Diamond surveyed 79 women aged 18 to 25 who considered themselves bisexual or lesbian, or who refused any label for their sexual orientation. She interviewed the women five times over a 10-year period from 1995 through 2005. Respondents gave detailed information on their sexual identities, attractions, behaviors and their social and familial relationships.
Diamond found bisexual and unlabeled women were more likely than lesbians to change their sexual identity over the 10 years. The bisexual or unlabeled women tended to switch between bisexual and unlabeled rather than to lesbian or heterosexual.
Nearly 20 percent of respondents switched from a bisexual or unlabeled identity to heterosexual, but more than half of these women switched back to bisexual or unlabeled.
By year 10 of the study, most of the women reported being involved in a long-term, monogamous relationship for more than a year.
The results suggest that women's definitions of lesbianism allowed more flexibility in sexual behavior than did their definitions of heterosexuality.
For instance, 15 percent of the women who identified as lesbian in the last round of interviews reported having sexual contact with a man during the prior two years. However, women who settled on a heterosexual label in the last interviews reported having no sexual contact with a woman within the previous two years.
"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 said.
Perhaps even more so than lesbians, bisexual women have more hurdles to clear before they are at the very least accepted by societies.
"One challenge facing bisexually identified women is that their identity is challenged by others," Galupo told LiveScience, "and that identity becomes assumed based on the relationships that they form — either lesbian if in a same-sex relationship or heterosexual if in an other-sex relationship."
Galupo mentions other misconstrued attitudes about bisexuality, including the idea "that it is adopted because it is trendy, or because bisexual individuals cannot make up their minds, that they are promiscuous, or that they have to be having multiple relationships with both women and men in order to maintain their identities."
In addition to nixing on-the-street prejudices, a more accurate understanding of bisexuality, Galupo noted, could have implications for the scientific field.
"Bisexuality is often defined by default — in terms of what it is not — bisexual individuals are neither heterosexual nor gay and lesbian. So understanding bisexuality can tell us a lot about our general definitions of sexuality," Galupo said.