Heterosexuality is romantic attraction, sexual attraction, or sexual behavior between people of the opposite sex or gender. As a sexual orientation, heterosexuality is "an enduring pattern of emotional, romantic, and/or sexual attractions" to people of the opposite sex. It "also refers to a person's sense of identity based on those attractions, related behaviors, and membership in a community of others who share those attractions." Someone who is heterosexual is commonly referred to as straight.
Along with bisexuality and homosexuality, heterosexuality is one of the three main categories of sexual orientation within the heterosexual–homosexual continuum. Across cultures, most people are heterosexual, and heterosexual activity is by far the most common type of sexual activity. Heterosexuality has mostly been viewed as the normative and most socially dominant form of sexual orientation.
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. Although no single theory on the cause of sexual orientation has yet gained widespread support, scientists favor biologically based theories. There is considerably more evidence supporting nonsocial, biological causes of sexual orientation than social ones, especially for males.
The term heterosexual or heterosexuality is usually applied to humans, but heterosexual behavior is observed in all other mammals and in other animals, as it is necessary for sexual reproduction.
Terminology
Hetero- comes from the Greek word ἕτερος [héteros], meaning "other party" or "another",Klein, Ernest, A Comprehensive Etymological Dictionary of the English Language: dealing with the origin of words and their sense development thus illustrating the history of civilization and culture, p. 345. Oxford: Elsevier, 2000 used in science as a prefix meaning "different"; and the Latin word for sex (that is, characteristic sex or sexual differentiation).
The current use of the term heterosexual has its roots in the broader 19th century tradition of personality taxonomy. The term heterosexual was coined alongside the word homosexual by Karl Maria Kertbeny in 1869. The terms were not in current use during the late nineteenth century, but were reintroduced by Richard von Krafft-Ebing and Albert Moll around 1890. The noun came into wider use from the early 1920s, but did not enter common use until the 1960s. The colloquial shortening "hetero" is attested from 1933. The abstract noun "heterosexuality" is first recorded in 1900.Mills, Jonathan, Love, Covenant & Meaning, p. 22, Regent College Publishing, 1997. The word "heterosexual" was listed in Merriam-Webster's New International Dictionary in 1923 as a medical term for "morbid sexual passion for one of the opposite sex"; however, in 1934 in their Second Edition Unabridged it is defined as a "manifestation of sexual passion for one of the opposite sex; normal sexuality".Katz, Jonathan Ned (1995) The Invention of Heterosexuality, p. 92. New York, NY: Dutton (Penguin Books).
Hyponyms of heterosexual include heteroflexible.Porn.com: Making Sense of Online Pornography - Page 229, Feona Attwood - 2010Patience: A Gay Man's Virtue - Page 80, La Lumiere - 2012
The word can be informally shortened to "hetero". 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. One of the first uses of the word in this way was in 1941 by author G. W. Henry.Henry, G. W. (1941). Sex Variants: A Study of Homosexual Patterns. New York: Paul B. Hoeber Henry's book concerned conversations with homosexual males and used this term in connection with people who are identified as ex-gays. It is now simply a colloquial term for "heterosexual", having changed in primary meaning over time. Some object to usage of the term straight because it implies that non-heterosexual people are crooked.Encyclopedia Of School Psychology - Page 298, T. Steuart Watson, Christopher H. Skinner - 2004
Demographics
In their 2016 literature review, Bailey et al. stated that they "expect that in all cultures the vast majority of individuals are sexually predisposed exclusively to the other sex (i.e., heterosexual)" and that there is no persuasive evidence that the demographics of sexual orientation have varied much across time or place. Heterosexual activity between only one male and one female is by far the most common type of sociosexual activity.
According to several major studies, 89% to 98% of people have had only heterosexual contact within their lifetime;Wellings, K., Field, J., Johnson, A., & Wadsworth, J. (1994). Sexual behavior in Britain: The national survey of sexual attitudes and lifestyles. London, UK: Penguin Books. Bogaert argues that: "The prevalence of male homosexuality is debated. One widely reported early estimate was 10% (e.g., Marmor, 1980; Voeller, 1990). Some recent data provided support for this estimate (Bagley and Tremblay, 1998), but most recent large national samples suggest that the prevalence of male homosexuality in modern western societies, including the United States, is lower than this early estimate (e.g., 1–2% in Billy et al., 1993; 2–3% in Laumann et al., 1994; 6% in Sell et al., 1995; 1–3% in Wellings et al., 1994). It is of note, however, that homosexuality is defined in different ways in these studies. For example, some use same-sex behavior and not same-sex attraction as the operational definition of homosexuality (e.g., Billy et al., 1993); many sex researchers (e.g., Bailey et al., 2000; Bogaert, 2003; Money, 1988; Zucker and Bradley, 1995) now emphasize attraction over overt behavior in conceptualizing sexual orientation." (p. 33) Also: "...the prevalence of male homosexuality (in particular, same-sex attraction) varies over time and across societies (and hence is a "moving target") in part because of two effects: (1) variations in fertility rate or family size; and (2) the fraternal birth order effect. Thus, even if accurately measured in one country at one time, the rate of male homosexuality is subject to change and is not generalizable over time or across societies." (p. 33) but this percentage falls to 79–84% when either or both same-sex attraction and behavior are reported.
A 1992 study reported that 93.9% of males in Britain have only had heterosexual experience, while in France the number was reported at 95.9%. According to a 2008 poll, 85% of Britons have only opposite-sex sexual contact while 94% of Britons identify themselves as heterosexual. Similarly, a survey by the UK Office for National Statistics (ONS) in 2010 found that 95% of Britons identified as heterosexual, 1.5% of Britons identified themselves as homosexual or bisexual, and the last 3.5% gave more vague answers such as "don't know", "other", or did not respond to the question. In the United States, according to a Williams Institute report in April 2011, 96% or approximately 250 million of the adult population are heterosexual.
An October 2012 Gallup poll provided unprecedented demographic information about those who identify as heterosexual, arriving at the conclusion that 96.6%, with a margin of error of ±1%, of all U.S. adults identify as heterosexual. The Gallup results show:
Age/GenderHeterosexualNon-heterosexualDon'tknow/Refused 18–2990.1%6.4%3.5% 30–4993.6%3.2%3.2% 50–6493.1%2.6%4.3% 65+91.5%1.9%6.5% 18–29, Women88.0%8.3%3.8% 18–29, Men92.1%4.6%3.3%
In a 2015 YouGov survey of 1,000 adults of the United States, 89% of the sample identified as heterosexual, 4% as homosexual (2% as homosexual male and 2% as homosexual female) and 4% as bisexual (of either sex).
Bailey et al., in their 2016 review, stated that in recent Western surveys, about 93% of men and 87% of women identify as completely heterosexual, and about 4% of men and 10% of women as mostly heterosexual.
Academic study Biological and environmental
No simple and singular determinant for sexual orientation has been conclusively demonstrated, but scientists believe that a combination of genetic, hormonal, and environmental factors determine sexual orientation. They favor biological theories for explaining the causes of sexual orientation, as there is considerably more evidence supporting nonsocial, biological causes than social ones, especially for males.
Factors related to the development of a heterosexual orientation include genes, prenatal hormones, and brain structure, and their interaction with the environment.
Prenatal hormones
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.Vilain, E. (2000). Genetics of Sexual Development. Annual Review of Sex Research, 11:1–25 It has been suggested that both male and female heterosexuality are the results of this process.Wilson, G. and Rahman, Q., (2005). Born Gay. Chapter 5. London: Peter Owen Publishers 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.
Animals and reproduction
Sexual reproduction in the animal world is facilitated through opposite-sex sexual activity, although there are also animals that reproduce asexually, including protozoa and lower invertebrates.The Columbia Encyclopedia (Colum. Univ. Press, 5th ed. [casebound?] 1993 ()), entry Reproduction.
Reproductive sex does not require a heterosexual orientation, since sexual orientation typically refers to a long-term enduring pattern of sexual and emotional attraction leading often to long-term social bonding, while reproduction requires as little as a single act of copulation to fertilize the ovum by sperm.Lawyers Guide to Forensic Medicine SBN 978-1-85941-159-9 By Bernard Knight - Page 188 "Pregnancy is well known to occur from such external ejaculation ..."
Sexual fluidity
Often, sexual orientation and sexual orientation identity are not distinguished, which can impact accurately assessing sexual identity and whether or not sexual orientation is able to change; sexual orientation identity can change throughout an individual's life, and may or may not align with biological sex, sexual behavior or actual sexual orientation.Sinclair, Karen, About Whoever: The Social Imprint on Identity and Orientation, NY, 2013 Sexual orientation is stable and unlikely to change for the vast majority of people, but some research indicates that some people may experience change in their sexual orientation, and this is more likely for women than for men. The American Psychological Association distinguishes between sexual orientation (an innate attraction) and sexual orientation identity (which may change at any point in a person's life).
A 2012 study found that 2% of a sample of 2,560 adult participants reported a change of sexual orientation identity after a 10-year period. For men, a change occurred in 0.78% of those who had identified as heterosexual, 9.52% of homosexuals, and 47% of bisexuals. For women, a change occurred in 1.36% of heterosexuals, 63.6% of lesbians, and 64.7% of bisexuals.
Heteroflexibility is a form of sexual orientation or situational sexual behavior characterized by minimal homosexual activity in an otherwise primarily heterosexual orientation that is considered to distinguish it from bisexuality. It has been characterized as "mostly straight".