Sexual orientation

Sexual orientation refers to the direction of an individual's sexuality, usually conceived of as classifiable according to the sex or gender of the persons that the individual finds sexually attractive. The most commonly used categories of sexual orientation are heterosexuality (being sexually attracted to members of the opposite sex), homosexuality (being sexually attracted to members of the same sex) and bisexuality (being sexually attracted to members of either sex).
A number of different classification schemes have been used to describe human sexuality. Indeed, several studies have found that much of the research regarding sexual orientation has failed to define the term at all, making it difficult to reconcile the results of different studies.[1] However, most definitions include a psychological component (such as the direction of an individual's erotic desire) and/or a behavioural component (which focuses on the sex of the individual's sexual partner/s). Some prefer simply to follow an individual's self-definition or identity.
More recently, scholars of sexology, anthropology and history have argued that social categories such as heterosexual and homosexual are not universal. Different societies may consider other criteria to be more significant than sex, including the respective age of the partners, the sexual role played by each partner (such as active or passive), or the social status of the partners.
Sexual identity may be used as a synonym for sexual orientation, but the two are also sometimes distinguished, with identity referring to an individual's conception of themselves, and orientation referring to "fantasies, attachments and longings"[2] and/or behavior. In addition, sexual identity is sometimes used to describe a person's perception of his or her own sex, rather than sexual orientation. The term sexual preference has a similar meaning to sexual orientation, but is more commonly used outside of scientific circles by people who believe that sexual orientation is, in whole or part, a matter of choice.


Sexual orientation and gender identity
The earliest writers on sexual orientation usually understood it to be intrinsically linked to the subject's own sex. For example, it was thought that a typical female-bodied person who is attracted to female-bodied persons would have masculine attributes, and vice versa.[13] This understanding was shared by most of the significant theorists of sexual orientation from the mid-19th to early 20th century, such as Karl Heinrich Ulrichs, Richard von Krafft-Ebing, Magnus Hirschfeld, Havelock Ellis, Carl Jung and Sigmund Freud, as well as many gender variant homosexual people themselves. However, this understanding of homosexuality as sexual inversion was disputed at the time, and through the second half of the 20th century, gender identity came to be increasingly seen as a phenomenon distinct from sexual orientation. Transgender and cisgender people may be attracted to men, women, or both, although the prevalence of different sexual orientations is quite different in these two populations (see sexual orientation of transwomen). An individual homosexual, heterosexual or bisexual person may be masculine, feminine, or androgynous, and in addition, many members and supporters of lesbian and gay communities now see the "gender-conforming heterosexual" and the "gender-nonconforming homosexual" as negative stereotypes. However, studies by J Michael Bailey and KJ Zucker have found that a majority of gay men and lesbians report being gender-nonconforming during their childhood years.[14]
A definitional problem arises with the terms "homosexual" and "heterosexual" when either the subject or object of desire is transgender or intersex. Is a transwoman who is attracted to other women a lesbian? What about her female partner? The majority of transgender people today would describe this relationship as lesbian, but scientists (especially in the past) have tended to characterise it as heterosexual, interpreting the sex of the transwoman as male, and basing the definition of sexual orientation on chromosomal and anatomical sex rather than social gender. Others would interpret the sexual orientation differently depending on whether the transwoman is "pre-operative" or "post-operative". Difficulties in making these judgements can be seen, for example, in debates about whether female-attracted transmen are a part of the lesbian community. (See Homosexuality and transgender)
For these reasons, the terms gynephilia and androphilia are occasionally (but increasingly) used when referring to the sexual orientation of transgender and intersex people (and occasionally, cisgender people), because rather than focusing on the sex of the subject, they only describe that of the object of their attraction. The third common term that describes sexual orientation, bisexuality, makes no claim about the subject's sex or gender identity. (See also Pansexuality)
Sexual orientation is further complicated by more recent non-binary understandings of both sex (male, female, or intersex) and gender (man, woman, transgender, third gender, or gender variant). Sociologist Paula Rodriguez Rust (2000) argues for a more multifaceted definition of sexual orientation


Demographics of sexual orientation
The multiple aspects of sexual orientation and the boundary-drawing problems already described create methodological challenges for the study of the demographics of sexual orientation. Determining the frequency of various sexual orientations in real-world populations is difficult and controversial.
In the oft-cited and oft-criticized Sexual Behavior in the Human Male (1948) and Sexual Behavior in the Human Female (1953), by Alfred C. Kinsey et. al., people were asked to rate themselves on a scale from completely heterosexual to completely homosexual. Kinsey reported that when the individuals' behavior as well as their identity are analyzed, most people appeared to be at least somewhat bisexual - i.e., most people have some attraction to either sex, although usually one sex is preferred. According to Kinsey, only a minority (5-10%) can be considered fully heterosexual or homosexual. Conversely, only an even smaller minority can be considered fully bisexual (with an equal attraction to both sexes).
Kinsey's methods have been criticized as flawed, particularly with regard to the randomness of his sample population, which included a large number of prison inmates. Nevertheless, Paul Gebhard, subsequent director of the Kinsey Institute for Sex Research, reexamined the data in the Kinsey Reports and concluded that accounting for major statistical objections barely affected the results. Most modern scientific surveys find that the majority of people report a mostly heterosexual orientation. However, the relative percentage of the population that reports a homosexual orientation varies with differing methodologies and selection criteria. Most of these statistical findings are in the range of 2.8 to 9% of males, and 1 to 5% of females for the United States[16] — this figure can be as high as 12% for some large cities and as low as 1% percent for rural areas). In gay villages such as The Castro in San Francisco, California, the concentration of self-identified homosexual people can exceed 40%. Almost all of these studies have found that homosexual males occur roughly at twice the rate of homosexual females. Estimates for the percentage of the population that identify as bisexual vary widely based on the type of questions asked. Some studies only consider a person bisexual if they are nearly equally attracted to both sexes, and others consider a person bisexual if they are at all attracted to the same sex (for otherwise mostly heterosexual persons) or to the opposite sex (for otherwise mostly homosexual persons).
A very small percentage of people are not sexually attracted to anyone (asexuality).