Suzanne Pennington. Encyclopedia of Gender and Society. Editor: Jodi O’Brien. Sage Publications, 2009.

Definitions of bisexuality have varied over time, and there is no single widely accepted meaning for the term. At present, it is commonly defined as a sexual preference/orientation or sexual identity in which an individual’s sexual, romantic, and/or emotional attraction is not limited to one sex/gender (i.e., categories such as female or male). This entry focuses broadly on bisexuality as a sexual identity or sexual preference as it has developed in the United States and will review differing definitions of bisexuality among scholars and bisexuals themselves. There is limited research on the number of people who behave bisexually and/or identify as bisexual, in part due to varying conceptualizations of bisexuality as well as the stigma surrounding bisexuality. Since the 1970s, there has been increasing activism by bisexuals who seek to affirm their sexual orientation and dispel negative stereotypes about bisexuals.

Defining Bisexuality

The meaning of bisexuality has developed within various academic disciplines, such as psychology, psychoanalysis, biology, and sexology, as well as within sexual identity politics or identity activism. Bisexual scholar and activist Clare Hemmings has noted three primary usages of the term “bisexuality”: (1) bisexuality as synonymous with hermaphroditism, the presence of male and female characteristics in one organism; (2) bisexuality as the coexistence in a human individual of both “masculine” and “feminine” psychological dispositions or personal characteristics; (3) and bisexuality as sexual attraction to both men and women.

History of Bisexuality in Psychiatry, Psychoanalysis, and Sexology

Social scientists have used the term bisexuality to refer to varying social phenomena involving human biology and sexuality. In the late 19th century, German psychiatrist Richard von Krafft-Ebing identified “psychosexual hermaphroditism” as the condition of patients in whom he observed desire for both women and men. British sexologist Havelock Ellis initially adopted this same terminology in his own work. Yet Ellis later began to use bisexuality to refer to sexual dimorphism, the simultaneous presence of female and male sex characteristics in one individual, as well as to sexual desire for both women and men.

Sigmund Freud puzzled over the role and meaning of bisexuality in his psychoanalytic theories of human psychosexual development. Freud continued to develop and redefine his understanding of bisexuality throughout his work on sexuality, which included theories of the origins of homosexuality and the development of masculinity and femininity. Freud initially referred to bisexuality as hermaphroditism but also came to view a bisexual potential in all individuals in terms of the possibility for desire toward females or males.

Freud postulated that before girls and boys experience the Oedipal conflict, they do not yet have a solid gender disposition as feminine or masculine. Accordingly, their sexual object-choice, or preference for female or male sexual partners, has not yet been established. Freud explained that pre-Oedipal females and males experience a bisexual potential before the cementing of a feminine or masculine disposition that directs desire toward one sex/gender. This bisexual potential is supposedly resolved for both girls and boys during the Oedipal conflict, when they cease to desire one or the other parent and repress one side of their bisexual disposition in accord with heterosexual social norms. Freud did not see bisexuality as a stable sexuality in healthy, mature adults.

In the late 1940s and early 1950s, the research findings of Alfred Kinsey and his collaborators presented a new model of sexuality in the United States. The group of researchers found that most individuals are not exclusively heterosexual or homosexual in their desires or sexual behaviors over the life span. From their national research on sexual behavior, the team of sexologists created the Kinsey Scale, or Continuum of Sexuality. The 7-point scale ranges from 0 to 6, with 0 representing exclusive heterosexuality and 6 representing exclusive homosexuality. Kinsey’s research found that the desires and sexual behaviors of most people range between these extremes and often vary throughout the life course. Some bisexuals interpret Kinsey’s work as the first scientific recognition of bisexuality as dual attraction for women and men and suggest that bisexuality encompasses all 5 points on the scale between 0 and 6. Kinsey himself sought to clarify understandings of bisexuality and, referencing his training as a biologist, scientifically rejected the notion of bisexuality as an anatomical condition wherein a person has both female and male anatomies. Kinsey also resisted the popular trend of labeling persons according to their sexuality, such as homosexuals, due to his observation of vast fluidity in individuals’ sexual behaviors. Yet the team’s research findings did recognize bisexuality in humans as desire for both females and males.

Bisexual Identity

In addition to psychological and sexological theories on bisexuality, there are also theories of bisexual identity. As with scholars and researchers of bisexuality, there is a lack of agreement among self-identified bisexual individuals as to what it means to be bisexual. As a sexual identity label, bisexuality is highly contested. Some bisexuals argue that bisexuality is a stable sexual orientation and identity and that bisexuals do not choose to be bisexual any more than homosexuals or heterosexuals choose to be oriented toward partners of one or the other sex/gender. No matter whether a bisexual chooses monogamy or non-monogamy, or marriage or celibacy, they are still bisexual. Other bisexuals assert that bisexuality is a behavior, not an identity, and in this way claim that bisexuality is much more pervasive than those who identify as bisexual. For example, if a woman who self-identifies as a lesbian has sex with men, some would argue that she is actually bisexual.

There is great variation among those who adopt a bisexual identity. Some individuals identify as bisexual without engaging in relationships or sexual activity with more than one sex/gender, or even without any sexual or relationship experience at all. Some individuals identify as bisexual on the basis of their desires or fantasies, with or without acting upon them. Many self-identified bisexuals have greater preference for partners of one sex/gender. Some bisexuals may continue to identify as bisexual while in long-term monogamous relationships, whereas others in that situation may take on homosexual or heterosexual identities. Some individuals experience their bisexuality as a stage between other sexual identities, such as when changing from a heterosexual identity to a homosexual identity.

In their study on self-identified bisexual, homosexual, and heterosexual adults in San Francisco, Weinberg, Williams, and Pryor observed that bisexuals tend to identify as heterosexual and to recognize heterosexual desires before homosexual desires. Bisexuals tend to take on an identity as bisexual at ages later than individuals who first identify as homosexual or heterosexual. It is difficult for many bisexuals to come out as bisexual and establish a stable sexual identity, since there is a great amount of social stigma and misunderstanding about bisexuality and also because many regions lack bisexual support groups or social networks. Bisexuals also experience great variability in their self-identification over time, a trend that may reflect shifts in greater preference or involvement with partners of one sex/ gender. Paula Rodriguez Rust found in her research on lesbians and bisexual women that the women who currently identified as bisexual were much more likely than women who identified as lesbian to have changed their sexual self-identities multiple times.

Identity in the Era of HIV/AIDS

At present, defining sexual identity and sexual practice has become a crucial health concern in the era of HIV/AIDS. A significant amount of research has shown that there are more people who behave bisexually, that is, who engage in sexual activity with multiple sex/genders, than there are individuals who identify as bisexual. This poses a significant stumbling block in attempts to stop the spread of HIV/AIDS, and the early focus on “gay” men has been reconceptualized. HIV/AIDS prevention efforts have begun to target “MSMs,” or men who have sex with men, as well as “WSWs,” or women who have sex with women. Such terminology seeks to avoid neglecting at-risk individuals by focusing on behaviors rather than identities or types of persons, as sexual behavior and sexual identity do not necessarily correlate.

Biphobia and Stereotyping

Like other nonheterosexuals, bisexuals may face social discrimination and negative stereotyping. Bisexual scholar and activist Robyn Ochs argues that bisexuals experience a unique form of discrimination called biphobia. Whereas homosexuals may experience homophobia, a fear or aversion of homosexuals by heterosexuals, bisexuals experience double discrimination: homophobia from the heterosexual community and hostility from homosexuals. For example, heterosexuals may stigmatize or devalue bisexuals as homosexuals. However, homosexuals may accuse bisexuals of concealing their same-sex desires and relationships to gain the social privilege of heterosexuals. Additionally, both homosexuals and heterosexuals may deny the existence of bisexuals by arguing, for instance, that bisexuals are just in an experimental phase or are denying their true homosexuality.

Several negative stereotypes about bisexuals reveal the tensions between bisexuals and homosexuals and between bisexuals and heterosexuals. A stereotype is a false generalization that is applied to all members of a social group. Bisexuals are stereotyped as “fence-sitters” who cannot make up their minds between homosexuality and heterosexuality. This is particularly argued in the case of previously lesbian-feminist-identified bisexual women who “sleep with the enemy” and take on male partners; lesbians may see them as “traitors” to their movement. Bisexual men, in particular, have also been stereotyped as sexually voracious “disease carriers,” indiscriminate in their insatiable sexual desires and spreading HIV/AIDS between the heterosexual and homosexual communities. There is a great deal of dissatisfaction with the bisexual label for these reasons but also because of the stigma and misunderstanding that many bisexuals perceive comes along with the identity label. Some use alternative labels for their sexuality, such as queer, pansexual, or open.

Research on the Prevalence of Bisexuality

Estimates of the prevalence of bisexuality are complicated by the lack of an accepted precise definition of bisexuality and the stigma surrounding same-sex sexual behavior. Who is counted or considered to be bisexual depends on how bisexuality is defined. Also, most research on sexuality does not differentiate bisexuals from homosexuals or does not include bisexuals at all.

Kinsey et al.’s national research on adult sexual behavior reported an unexpected amount of same-sex sexual behavior in Sexual Behavior in the Human Male (1948) and Sexual Behavior in the Human Female (1953). Bisexual behavior was, according to their data, more common than exclusively homosexual or heterosexual behavior. Kinsey et al. reported that 25 percent to 28 percent of women and 46 percent of men had been erotically responsive to or sexually active with both women and men.

However, Kinsey’s research has met with criticism, as the individuals who participated in the research (including volunteers, students, and prisoners) were not representative of the general American population. The 1994 National Health and Social Life Survey (NHSLS) is regarded as a much more scientifically sound study of sexuality in the United States. In this survey, 3.9 percent of males and 4.1 percent of women reported sexual attractions to persons of both genders. This study also reported that 2.0 percent of men identify as gay, 0.9 percent of women identify as lesbian, 0.8 percent of men identify as bisexual, and 0.5 percent of women identify as bisexual.

Bisexual Movement

The modern bisexual movement in the United States originated during the lesbian-feminist, gay, and sexual liberation movements of the 1970s. Bisexuals participated in these movements and also created exclusive bisexual organizations, which were initially social or informal support groups. As bisexuality became increasingly more invisible as well as stigmatized, some social groups became increasingly political. Bisexual activists seek to increase the visibility of bisexuals as a sexual minority identity and to decrease social discrimination and the negative stereotyping of bisexuals.

Bisexual activists do not agree on whether or not to form coalitions and work within existing gay and lesbian activist agendas. Some bisexuals think it is necessary to organize separately from “monosexuals,” or heterosexuals and homosexuals, who are attracted to one sex/gender. Propelled by increasing tension between, especially, bisexual women and lesbian feminists, some bisexual activists sought the formation of exclusive bisexual organizations. In 1983, the first political bisexual organization, BiPOL, was formed by bisexual feminists in San Francisco. Other bisexual activists work within and alongside lesbian and gay groups, and efforts began in the 1980s to change the names of many lesbian and gay organizations and events to formally include bisexuals. For example, a 1993 political rally was renamed “March on Washington for Lesbian, Gay, and Bi Equal Rights and Liberation,” a change toward greater inclusion that many bisexual activists perceived as crucial to success.

Bisexual activism began to spread during the 1980s from the United States to other regions, such as Canada, the United Kingdom, Europe, and New Zealand. The bisexual movement in the United States began to solidify with the start of regional conferences in the mid-1980s, followed by the first national bisexual conference in 1990. The first international conference on bisexuality was held in 1991. Also in the 1990s, some bisexual activists formed coalitions with the transgender movement. There has been increasing inclusion of “B” (bisexual) and “T” (transgender) into “LGBT” (lesbian, gay, bisexual, transgender) activism. Since the 1990s, some bisexuals have been involved in activism under the “queer” umbrella, a movement that seeks to eradicate all sexual identity labels.


The meaning of bisexuality was once contested within the scientific community, and now bisexuality is a controversial sexual identity. Debates about the meaning of bisexuality do not seem likely to be resolved in the near future. There exists only a small body of literature and academic research on bisexuals. Research on bisexuality is complicated by the challenges of acquiring a representative sample of bisexuals from which findings can be applied to a general bisexual population. Yet the bisexual movement is growing, and the social visibility and representation of bisexuals is increasing over time.