Lisa Diamond's seventh interview is the one that she remembers best. She had recruited "subject 007" at Cornell University, where she was studying how women who express attraction to other women come to understand their sexual identity. One early evening in 1995, in a conference room on the university campus, she settled down to ask the first question of her subject.
How did 007 currently identify herself on the spectrum of sexual identities? The woman answered that she didn't know. She told Diamond that she had been heterosexual all her life until just that last week, when she suddenly found herself falling in love with her best friend—a woman. They had had sex a couple of times, something she described as very satisfying. Part of Diamond's work was to categorize her subjects based on how they self-identified, but 007 wasn't sure—so Diamond put her into the "unlabeled" category.
By the time 007 left after the two hour interview, Diamond had tentatively concluded that the woman would come out as bisexual in her follow-up interview. But 007 never did. The interaction marked the beginning of Diamond's gradual realization that her assumptions about sexuality needed to change. In addition to the static orientations that most of us think about, like heterosexual, gay, and bisexual, some people experience shifts in their attractions that don't fit into static orientations. In Diamond's group, in fact, most did.
As she made her way through her 88 other subjects, Diamond asked each woman to fill out a pie chart indicating, in percentages, how much of her sexual attraction was directed to women, and how much to men. When Diamond followed up with 007 and her other subjects in 1997, she found something interesting: The make-up of their pie charts had shifted, and about 32 percent had changed their sexual identity labels.
It was on a flight to Los Angeles to visit her parents, in the middle of reading interview transcripts and making notes, that Diamond had an "aha" moment. She realized that she had been expecting, and imposing, conventional "coming out" stories: a falsification of sexual identity followed by a revealing of the true self. But "that's not actually what people [were] saying," Diamond recalls.
Re-reading her transcripts, Diamond realized that many of her subjects had not been misrepresenting their previous identities at all. Instead, they were moving from one genuine, persistent identity (and label) to another.
As Diamond followed up every two years with the women she was studying, her hypothesis found new support. "They were moving in all possible directions," says Diamond. In 2005, 10 years after she began her study, the pie charts continued to change, and about 67 percent of the women had changed their sexual identity labels at least once. Many self-labeled lesbians had unlabeled themselves. Most of the women who had initially preferred not to have a label had taken on the bisexual label. Some unlabeled women became lesbian, and others heterosexual.
These changes were often provoked by a single relationship. After two years of being in a same-sex relationship, subject 007 identified as heterosexual. Some women said that they were attracted to just one person of the same sex ("it's only her"), but were otherwise straight. Some women fell in love with their best female friends later in life, around 40, and started sexual relationships. Some longtime lesbians began heterosexual relationships.
So were these women straight or gay? The question may be the wrong one to ask, says Diamond. "[Women] over time tended to move toward an identity that allowed for more flexibility. Labels sometimes negate the more complicated experiences they have had." Diamond referred to these women as sexually fluid.
Sexual fluidity is different from homosexuality or heterosexuality, which are single orientations. "Fluidity allows people to go outside their orientation," Diamond says. Some individuals have steady patterns of attraction their entire lives that are consistent with their orientation. But for the sexually fluid, their orientation is not the last word on their attraction.
Sexual fluidity was dismissed as "inconvenient noise cluttering the real data."
Sexual fluidity is also not the same thing as bisexuality, which is another sexual orientation. "Bisexuality refers to an attraction to both males and females," explains Leila Rupp, a social scientist at the University of California, Santa Barbara, "while sexual fluidity refers to shifting attractions and desires." Bisexuals who are consistently attracted to males and females over their entire lives are not sexually fluid. Fluid bisexuals, on the other hand, can be attracted only to males or only to females for periods of time.
In her 2008 book Sexual Fluidity, Diamond says sexual fluidity is actually relatively common. It's not a conclusion that everyone agrees with: Qazi Rahman, a senior lecturer of cognitive neuropsychology at King's College London, for example, suggests that her study was too small to "tell us much about women in general." But Charlotte Tate, a gender and sexuality psychologist at San Francisco State University, says that Diamond's sample size is larger than the recommended sample size for qualitative research, and considers Diamond's findings significant. "Sexual fluidity is a real phenomenon," says Tate. "It is a part of the human experience."
In the riot of sexual orientations that have become recognized only in the last decade or so (Facebook famously has about 70), sexual fluidity may be one of the more difficult to understand, and one of the more neglected. It is, after all, not really an orientation at all.
In 1950, the gay rights activist Harry Hay founded America's first national gay rights organization, the Mattachine Society in Los Angeles. Its aim was to eliminate discrimination against homosexuals, assimilate them into mainstream society, and create an "ethical homosexual culture." It did not, however, quite speak for bisexuals. The first American pro-gay magazine, One, emerged from the Mattachine Society and launched in 1953 with the tagline "the homosexual viewpoint." Bisexuals were not a major part of the vocabulary in the gay movement. There were even statements from within the non-heterosexual community against bisexuality. One 1974 academic study found that "the lesbian community cannot deny the existence of bisexual behavior but its members do not encourage it, and they do not easily accept women with bisexual identification."
Robyn Ochs, who came out as bisexual in 1982 and has been campaigning for bisexual rights ever since, remembers some gay marches before the mid-1990s as unwelcoming. "Lesbian women thought that we were sleeping with the enemy," says Ochs. Dawne Moon, a sociologist at Marquette University, explains that some gay people felt that bisexuals were watering down their message. Any kind of sexual variability outside of homosexuality would threaten the narrative of the gay movement, says Moon. That narrative revolved around same-sex attraction being as authentic and fixed an orientation as heterosexuality.
The scientific practice of the 1960s through the early 1990s reinforced this message. Some researchers blatantly denied the existence of bisexuals. In 1956, the American psychoanalyst Edmund Bergler described bisexuality as "a state that has no existence beyond the word itself" and an "out-and-out fraud." Other researchers used terms like "true homosexuals" in their studies. It was common for academics to lump bisexuals and homosexuals together.
Even many school and college textbooks did not quite recognize bisexuality as a possible sexual orientation until about a decade ago. Bisexuality was seen to be a phase some people go through before identifying as heterosexual or homosexual. Kenji Yoshino, professor of constitutional law at New York University School of Law famously called this phenomenon "bisexual erasure" in an essay he wrote in the Stanford Law Review in 2000. "It is as if self-identified straights and self-identified gays have concluded that whatever their other disagreements, they will agree that bisexuals do not exist," Yoshino says.
If the narrative departure represented by bisexuality was discouraged, sexual fluidity—which denied the very idea of static orientation—was an even more remote afterthought, even though it had been observed in the academic literature by the late 1970s. "The notion of sexual fluidity is not a new one," writes Diamond in Sexual Fluidity. A 1977 study of 156 bisexual male and female college students found that some had consistent patterns of attraction over time while others did not.1 The authors proposed that sexuality is not fixed at a young age, but could vary over a lifetime. A few other studies over the next decade made similar insights, underscoring the importance of time in measuring human attraction. At one point, some researchers devised a new model for quantifying sexuality that included the element of time.2 Yet the model, along with these early studies, failed to have much of an impact.
Diamond says that when the early studies on sexual fluidity came out, many researchers still did not recognize bisexuality as a valid orientation. And that posed a special challenge for sexual fluidity. If researchers were not convinced of a person's ability to be attracted to both sexes, it was that much harder for them to recognize a person's temporally segregated attraction to both sexes. And so, says Diamond, sexual fluidity suffered a similar fate as bisexuality, and was dismissed as "inconvenient noise cluttering the real data on sexual orientation."
Tate agrees that scientists were under the sway of an alternative interpretation of sexuality. "Sexual fluidity has probably always existed," she says, but most scientists were committed to an incompatible narrative, in which sexuality is fixed at a young age. "Scientists tried to erase or deny everything that did not fit into that narrow story," she says. "Even in 2016, only some of us in behavioral science are able to see through this pretense."
By the time Diamond met subjects like 007, the idea of sexual fluidity was still inchoate. But she was drawn to the marginal studies on bisexuality and sexual fluidity, which ultimately gave her the groundwork to distinguish orientation from attraction over time. Many researchers consider Diamond's work to be definitive, providing the first systematic evidence of fluidity in a longitudinal study, and likely the first to use the term sexual fluidity.
Even today only a few people study sexual fluidity. But researchers believe it has the potential to improve lives, just like the recognition and acceptance of homosexuality did. In the words of Erin Davis, a sociologist at Cornell College, recognition of sexual fluidity can mean that "[people] do not have to discount past experiences or limit future options."
I met Steph one afternoon early this year in her Brooklyn apartment, where she lives with her partner Marissa (which is not her real name) and their two cats. A wind chime Steph's father made hangs in the kitchen, and a blanket her mother hand knit for the couple is on a living room chair. Around the apartment are many photographs of Steph and Marissa on hiking and road trips.
Steph's earliest memory of same-sex attraction dates to when she was 13, and devastated after her sister had died in a train-car collision. Steph found solace in her friend, Jill. They hung out together, and had a lot of sleepovers. At one point while on a vacation, they had a conversation about what it would mean if they kissed, which they never did. Later their friendship became awkward and ended on its own. "I always had some attractions toward women but didn't acknowledge them," says Steph. "I come from a small town in the Midwest where that [same-sex attraction] might be inappropriate. I never questioned it."
At 16, she fell in love with a guy. "He was cute and very smart, and also an athlete," says Steph. She describes the relationship as happy—until he became depressed and abusive in the fifth year of their relationship. Steph decided to call it off. They were about to get married. "I really loved him," she says.
While she was recovering from the heartbreak, Steph left her home in Michigan and went to Ecuador on a study abroad program. There, she developed an attraction to a close friend, Christine, who had just come out as a lesbian. A kiss between them would confirm to Steph that she was experiencing a real same-sex attraction. "It felt really good," says Steph. But she also says that moment was scary. A part of her did not want it to feel good. "It would have been easier to not feel gay," she tells me. So she told herself that maybe it could just be Christine. "I was in that bubble for a while," she says.
After Steph came back to Michigan, she and Christine hung out for a while, but their relationship did not work out because Steph was still struggling with her sexual identity, while Christine was un-closeted. Then a chance meeting with Diamond changed how Steph viewed her sexual self.
"People now associate [sexual fluidity] with freedom and self-determination."
In 2005, as a senior in psychology at Michigan's Kalamazoo College, Steph was looking for internship opportunities in the field of sexual identity development and came across some research papers written by Diamond. Steph wrote to her asking if she needed any help. At that time, Diamond had just completed the final interviews for her 10-year longitudinal study following women and was working on her book manuscript. She wrote back to Steph saying that she needed another set of eyes to go through the data and transcripts.
A couple months later, Steph flew to Salt Lake City to work with Diamond. When she started flipping through the tables and pie charts she said to herself, "Oh! Alright! Me too!" She felt validated to see other women whose sexual attractions changed over time, and who didn't adhere to a single sexual identity label. Until that point, she didn't know many people like her. She was amazed to see the sexual transitions in the study's women. "I was like, that shit is crazy. This is complex," Steph laughs, throwing her hands in the air. She found herself in those stories, she says.
Coming back to Kalamazoo, Steph became a little more open about her sexuality. She came out as bisexual to her parents over dinner. She called herself bisexual because at that time she was still sleeping with men. Her dad said that he was not shocked but a little surprised. Steph's mother was also accepting, and she and Steph later had several conversations about how Steph could embrace her sexuality.
Steph is quick to clarify that her story is "not a coming out" story. "My five years of relationship with my boyfriend were not false. I actually make a point of telling people that. I loved him very much and I was very much attracted to him," she says. Over time, Steph started identifying as queer because that category recognizes that her gender and sexuality are more fluid. Today if you ask Steph to draw her sexual attraction pie chart, she would assign 80 percent to women and 20 percent to men. She finds men's bodies sexually attractive but with women her connection is both emotional and sexual.
Steph's story shows how impactful the recognition of fluidity can be: Diamond's work served as a catalyst for her recognition and acceptance of her own type of sexual attraction. But it isn't known how many others like Steph are out there. The U.S. Department of Health and Human Services published a survey in 2016 of over 10,000 American adults, in which 17 percent of women and 6 percent of men reported they'd had at least some kind of same-sex contact in their lifetime. There were more self-identified bisexuals (5.5 percent of women and 2 percent of men) than those who identified as exclusively homosexual (1.3 percent of women and 1.9 percent of men). About 92 percent of women and 95 percent of men called themselves straight. The survey did not include sexual fluidity as an option. It also did not track adults through time to see how their patterns of sexual attraction may have changed. "There are likely to be sexually fluid people embedded in all of the categories represented in the study," says Diamond.
A few recent studies of large populations, however, have identified change in attractions over time. One study of about 1,000 New Zealanders between ages 21 and 38 found that a significant number of them experienced variability in their sexual attraction over time. Among 21-year-old women, up to 9 percent had same-sex attractions, which increased to 16 percent by age 28, and then fell to 12 percent by age 38. Among the 21-year old men, 4.2 percent had homosexual attractions, which went up to 6.5 percent by age 38.3 There is evidence that these changes can continue well into middle age. A 2012 meta-study of data from the National Survey of Midlife Development in the United States found that over a 10-year period, adults (with a mean age of 47 at the beginning of the study) exhibited variability in their sexual identity. Almost 3 percent of women and 2 percent of men changed their identity over the 10-year period.4
Diamond explains that it's possible that some of these changes are the result of individuals coming out, or indications that sexual orientation takes longer to develop than scientists originally thought. But sexual fluidity could also be a cause: "Sexual fluidity helps explain why there are so many changes at the population level," she says.
Diamond is happily surprised by the proliferation of artists and celebrities who have identified as sexually fluid, and associate it with a kind of liberation. Model Cara Delevingne, musician St. Vincent, and actor Nico Tortorella are just a few of the high-profile individuals who resist traditional labels and describe their sexuality as fluid. Although it's not clear if these celebrities fit Diamond's strict definition of sexually fluid, Diamond is clearly moved by the fact that the term has cultural resonance. "It is very exciting. It blows my mind. I never expected it to happen," Diamond says. "People now associate [sexual fluidity] with freedom and self-determination."
Inspired by Diamond's work herself, Steph moved to New York in 2007 to do her Ph.D. in social psychology, with a focus on gender discrimination, at City University of New York, and met Marissa, her current partner, in a gay basketball league. This spring, during a hike to the top of a mountain with a view of the New York City skyline, Steph reached into her pocket and took out a tiny plastic packet containing a wooden ring. Marissa said yes. That night, in a Brooklyn backyard filled with candles and food catered from a local BBQ restaurant, they celebrated with their families.
As for 007? She married a man and had kids, and has not told anyone, not even her husband, about her sexually fluid past.
Ankur Paliwal is a journalist who writes on science, health, and the environment.
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1. Blumstein, P.W. & Schwartz, P. Bisexuality: Some social psychological issues. Journal of Social Issues 33, 30-45 (1977).
2. Klein, F., Sepekoff, B., & Wolf, T.J. Sexual orientation: A multi-variable dynamic process. Journal of Homosexuality 11, 35-49 (1985).
3. Dickson, N., van Roode, T., Cameron, C., & Paul, C. Stability and change in same-sex attraction, experience, and identity by sex and age in a New Zealand birth cohort. Archives of Sexual Behavior 42, 753-763 (2013).
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