Bisexuality is romantic attraction, sexual attraction , or sexual behavior toward both males and females,   or to more than one sex or gender. The term bisexuality is mainly used in the context of human attraction to denote romantic or sexual feelings toward both men and women,   and the concept is one of the three main classifications of sexual orientation along with heterosexuality and homosexuality , all of which exist on the heterosexual—homosexual continuum. A bisexual identity does not necessarily equate to equal sexual attraction to both sexes; commonly, people who have a distinct but not exclusive sexual preference for one sex over the other also identify themselves as bisexual. Scientists do not know the exact cause of sexual orientation, but they theorize that it is caused by a complex interplay of genetic , hormonal , and environmental influences ,    and do not view it as a choice. Bisexuality has been observed in various human societies  and elsewhere in the animal kingdom    throughout recorded history. The term bisexuality , however, like the terms hetero- and homosexuality , was coined in the 19th century.
Lesbian and Bisexual Women Health | CDC
The authors do not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and have disclosed no relevant affiliations beyond their academic appointment. Since , social scientists have studied the General Social Survey to chart the complexities of social change in the United States. The survey, which is conducted every couple of years, asks respondents their attitudes on topics ranging from race relations to drug use. In , the survey started including a question on sexual identity. In the 10 years that the General Social Survey has included a question on sexual identity, rates of identification among gay men, lesbian women and bisexual men in the U.
Bisexuality in women
Bisexuals, who account for about four-in-ten LGBT adults in the United States, stand apart from gay and lesbian adults in many ways, such as the fact that they are less likely to view their sexual orientation as central to their identity. The experience of coming out to friends and family can be complex. Among those who did come out, bisexual adults report somewhat different experiences from gays and lesbians. Gays and lesbians are somewhat less likely to report being solely attracted to one gender.
A general description is provided of the sexual relationships of the respondents. The major focus is on the wide diversity of self-identified bisexual women, especially in terms of self-perceived sexual and emotional needs, circumstances precipitating heterosexual and homosexual behavior, and ideological supports for a bisexual life style. Heterosexual behavior among homosexual women is discussed in terms of economic necessity, experimentation, and the response of the lesbian community.