Heterosexuality

Heterosexuality (frequently referred to as Hetero) is sexual or romantic attraction between opposite sexes, and is the most common sexual orientation among humans. The current use of the term has its roots in the broader 19th century tradition of personality taxonomy. These continue to influence the development of the modern concept of sexual orientation, gaining associations with romantic love and identity in addition to its original, exclusively sexual meaning.

The adjective heterosexual is used for intimate relationships and/or Human sexual behavior between male and female individuals, who may or may not identify themselves as straight. Heterosexuality, as an identifier, is usually contrasted with homosexuality and bisexuality. The term straight is used predominantly to refer to self-identified heterosexuals of either sex. Unlike lesbian, there is no gender-specific term that is only used for self-identified heterosexual females.

Etymology
Hetero- comes from the Greek word heteros, meaning "different" (for other uses, see heterozygote, heterogeneous), and the Latin for sex (that is, characteristic sex or sexual differentiation). The term "heterosexual" was coined shortly after and opposite to the word "homosexual" by Karl Maria Kertbeny in 1868 and was first published in 1869. [2] "Heterosexual" was first listed in Merriam-Webster's New International Dictionary as a medical term for "morbid sexual passion for one of the opposite sex", but in 1934 in their Second Edition Unabridged it is a "manifestation of sexual passion for one of the opposite sex; normal sexuality". (Katz, 1995)

The term heterosexual can be used to describe individuals' sexual orientation, sexual history, or self-identification. Many people reject the term "heterosexual" as too clinical and dehumanizing as the word only refers to one's sexual behavior, and does not refer to non-sexual romantic feelings. As a result, the terms straight is usually preferred when discussing a person of this sexual orientation, whose sexual history is predominated by this behavior, or who identifies as such. Some opposite-sex oriented people personally prefer the term "heterosexual" rather than "straight", as they may perceive the former as describing a sexual orientation and the latter as describing a cultural or socio-political group with which they do not identify.

New terms are arising for use in situations where specificity is important. For example, men who have sex with men, or MSM for short, is sometimes used in the medical community when specifically discussing sexual behavior (regardless of sexual orientation or self-identification). Non-straight is another attempt at neutrality that is gaining currency. Some other terms are now becoming more prevalent, including heteroflexible to refer to a person who identifies as heterosexual, but occasionally engages in same-sex sexual activities, or metrosexual to denote a straight man with stereotypically gay tastes in food, fashion and design.

Academic study
Heterosexuality, like any forms of identity is very subjective. In western society, one is generally thought of as heterosexual if one derives either all, or the vast majority of their erotic and/or sexual stimulation from people of the different sex to them. In other cultures a heterosexual man may engage in homosexual intercourse provided that he keeps the role traditionally assigned to his sex during intercourse and his gender during the surrounding relationship. Also, in some cultures a heterosexually identifying man may assume any role during homosexual congress as a social action provided he maintain a relationship with a woman in his family life. Cultural allowances such as this have been historically rarer amongst women, but more recently have been tolerated more than the male equivalents largely because of its connection to some schools of feminism.

Definitions of sexuality tend to be narrower to most heterosexuals than it is to people of other sexual orientations. In most cases a potential partner's sex is determined wholly by anatomic sex at birth and genetic sex. Many heterosexuals would argue that one whose determination of a partner's sex deviates from that criterion cannot truly be heterosexual. Transgendered people and even those with many natural intersex conditions are very rarely seen as potential mates by heterosexuals, even those who consider themselves tolerant and accepting to such identities.

Prenatal hormonal theory
The neurobiology of the masculinization of the brain is fairly well understood. Estradiol, and testosterone, which is catalyzed by the enzyme 5α-reductase into dihydrotestosterone, act upon androgen receptors in the brain to masculinize it. If there are few androgen receptors (people with Androgen insensitivity syndrome) or too much androgen (females with Congenital adrenal hyperplasia) there can be physical and psychological effects. It has been suggested that both male and female heterosexuality are results of variation in this process. In these studies heterosexuality in females is linked to a lower amount of masculinization than is found in lesbian females, though when dealing with male heterosexuality there are results supporting both higher and lower degrees of masculinization than homosexual males. (See the main article for further details.)

Physiological differences in heterosexual persons

 * See: Physiological differences

Natural selection
An array of opinion holds that much human behavior is ultimately explainable in terms of natural selection. From this point of view, the shifting social balance between heterosexual and homosexual desire has evolved more as a fitter survival strategy for the species than either an exclusively heterosexual or homosexual configuration of desire.

Heterosexual behaviors in animals
In the animal kingdom, sexual reproduction results from heterosexual coitus between sexually mature partners.

Behavioral Studies
At the beginning of the 20th century, early theoretical discussions in the field of psychoanalysis posited original bisexuality in human psychological development. Quantitative studies by Alfred Kinsey in the 1940s and Dr. Fritz Klein's sexual orientation grid in the 1980s find distributions similar to those postulated by their predecessors.

Many modern studies, most notably Sexual Behavior in the Human Male and Sexual Behavior in the Human Female by Alfred Kinsey, have found that the majority of humans have had both heterosexual and homosexual experiences or sensations, and are bisexual. Contemporary scientific research suggests that the majority of the human population is bisexual, adhering to a fluid sexual scale rather than a category, as Western society typically views sexual nature. However, social pressures influence people to adhere to categories or labels rather than behave in a manner that more closely resembles their nature as suggested by this research.

Kinsey himself, along with current sex therapists, focus on the historicity and fluidity of sexual orientation. Kinsey's studies consistently found sexual orientation to be something that evolves in many directions over a person's lifetime; rarely, but not necessarily, including forming attractions to a new gender. Rarely do individuals radically reorient their sexualities rapidly — and still less do they do so volitionally — but often sexualities expand, shift, and absorb new elements over decades. For example, socially normative "age-appropriate" sexuality requires a shifting object of attraction (especially in the passage through adolescence). Contemporary queer theory, incorporating many ideas from social constructionism, tends to look at sexuality as something that has meaning only within a given historical framework. Sexuality, then, is seen as a participation in a larger social discourse, and, though in some sense fluid, not as something strictly determinable by the individual.

Most sexual orientation specialists follow the general conclusion of Alfred Kinsey regarding the sexual continuum, according to which a minority of humans are exclusively heterosexual or homosexual, and that the majority are bisexual. The consensus of psychologists is that sexual orientation, in most individuals, is shaped at an early age; and is not voluntarily changeable.

Other studies have disputed Kinsey's methodology. "His figures were undermined when it was revealed that he had disproportionately interviewed homosexuals and prisoners (many sex offenders)." However, Kinsey's idea of a sexuality continuum still enjoys acceptance today and is supported by findings in the human and animal kingdoms including biological studies of structural brain differences between those belonging to different sexual orientations.

Sexologists have attributed discrepancies in some findings to negative societal attitudes towards a particular sexual orientation. For example, people may state different sexual orientations depending on whether their immediate social environment is public or private. Reluctance to disclose one's actual sexual orientation is often referred to as "being in the closet". Individuals capable of enjoyable sexual relations with both sexes or one sex may feel inclined to restrict themselves to heterosexual or homosexual relations in societies that stigmatise same-sex or opposite-sex relations. In traditional societies, individuals are often under heavy social pressure to marry and have children, irrespective of their desired sexual orientation.

Although the concept of three basic sexual orientations is widely recognized, a small minority maintain that there are other legitimate sexual orientations besides homosexuality, bisexuality and heterosexuality. These may include significant or exclusive orientation towards a particular type of transsexual or transgender individual (e.g. female-to-male transsexual men), intersexed individuals, or those who identify as non-gendered or other-gendered.

Nature versus nurture
Considerable debate exists over whether predominantly biological or psychological factors produce sexual orientation in humans. Candidate factors include genes and the exposure of fetuses to certain hormones (or lack thereof). Historically, Freud and many others psychologists, particularly in psychoanalytic or developmental traditions, speculated that formative childhood experiences helped produce sexual orientation; as an example Freud believed that all human teenagers are predominantly homosexual and transition to heterosexuality in adulthood; those who remain homosexual as adults he believed had experienced some traumatic event that arrested their sexual development; however, he did believe all adults, even those who had healthy sexual development still retained latent homosexuality to varying degrees. Although there is currently no general medical consensus, one theory is that biological factors — whether genetic or acquired in utero — produce characteristically homosexual childhood experiences (such as atypical gender behaviour experiences), or at the least significantly contribute to them.

The APA currently officially states that sexual orientation is not chosen and cannot be changed, a radical reversal from the recent past, when non-normative sexuality was considered a deviancy or mental ailment treatable through institutionalization or other radical means.

Critique of studies
The studies performed in order to find the origin of sexual orientation have been criticized for being too limited in scope, mostly for focusing only on heterosexuality and homosexuality as two diametraically opposite poles with no orientation in between.

It is also asserted that scientific studies focus too much on the search for a biological explanation for sexual orientation, and not enough on the combined effects of both biology and psychology.

In a brief put forth by the Council for Responsible Genetics, it was stated that sexual orientation is not fixed either way, and, on the discourse over sexual orientation: "Noticeably missing from this debate is the notion, championed by Kinsey, that human sexual expression is as variable among people as many other complex traits. Yet just like intelligence, sexuality is a complex human feature that modern science is attempting to explain with genetics... Rather than determining that this results from purely biological processes, a trait evolves from developmental processes that include both biological and social elements. In addition, scientists rarely take into consideration sexual preferences that are not described by the two poles heterosexual and homosexual, 'in hopes of maximizing the chance that they will find something of interest.'" According to the American Psychiatric Association (APA), there are numerous theories about the origins of a person's sexual orientation, but some believe that "sexual orientation is most likely the result of a complex interaction of environmental, cognitive and biological factors", and that genetic factors play a "significant role" in determining a person's sexuality. [5]

History and demographics
The prevalence of exclusive heterosexuality has varied over the centuries and also from culture to culture. See Demographics of sexual orientation

Though there have always been individuals (sometimes in a majority, sometimes in a minority) who were exclusively attracted to those of the opposite sex, heterosexuality as an identity (just like homosexuality) has developed only since the middle of the nineteenth century.

The history of heterosexuality is part of the history of sexuality. That history and science derivative of it is far from complete. Owing to complications of human politics and prejudice, coupled with the malleable nature of human behaviour, it will be some time before the history and nature of all forms of human sexual behaviour are truly known.

Slang
The term "straight" originated as a mid-20th century gay slang term for heterosexuals, ultimately coming from the phrase "to go straight" (as in "straight and narrow"), or stop engaging in homosexual sex. [3] One of the first uses of the word in this way was in 1941 by author G. W. Henry. Henry's book concerned conversations with homosexual males and used this term in connection with the reference to ex-gays. It currently simply is a colloquial term for "heterosexual" having, like many words, changed in primary meaning over time.

The term breeder, a word which is normally applied to animals, is sometimes used (typically by homosexual men) to describe heterosexuals in a negative way.

Books

 * Kinsey, Alfred C., et al., "Sexual Behavior in the Human Male". Indiana University Press. ISBN 0-253-33412-8
 * Kinsey, Alfred C., et al., "Sexual Behavior in the Human Female". Indiana University Press. ISBN 0-253-33411-X