Heteronormativity is the definition of heterosexuality as the normative human sexuality. It assumes that sexual and marital relations are most fitting between people of the opposite sex and upholds the gender binary (i.e., that there are only two distinct, opposite genders).

Heteronormativity creates and upholds a social hierarchy based on sexual orientation with the practice and belief that heterosexuality is deemed as the societal norm.Ray, T. N., & Parkhill, M. R. (2021). Heteronormativity, Disgust Sensitivity, and Hostile Attitudes toward Gay Men: Potential Mechanisms to Maintain Social Hierarchies. Sex Roles, 84(1/2), 49–60. A heteronormative view, therefore, involves alignment of biological sex, sexuality, gender identity and gender roles. Heteronormativity has been linked to heterosexism and homophobia, and the effects of societal heteronormativity on lesbian, gay and bisexual individuals have been described as heterosexual or "straight" privilege.

Etymology Michael Warner popularized the term in 1991, in one of the first major works of queer theory. The concept's roots are in Gayle Rubin's notion of the sex/gender system and Adrienne Rich's notion of compulsory heterosexuality. From the outset, theories of heteronormativity included a critical look at gender; Warner wrote that "every person who comes to a queer self-understanding knows in one way or another that her stigmatization is intricated with gender. ... Being queer ... means being able, more or less articulately, to challenge the common understanding of what gender difference means." Lauren Berlant and Warner further developed these ideas in their seminal essay "Sex in Public":

Relation to marriage and the nuclear family Modern family structures in the past and present vary from what was typical of the 1950s nuclear family. In the United States, the families of the second half of the 19th century and early 20th century were characterized by the death of one or both parents for many American children. In 1985, the United States is estimated to have been home to approximately 2.5 million post-divorce, stepfamily households containing children. During the late 1980s, almost 20% of families with children headed by a married couple were stepfamilies.

Over the past three decades, rates of divorce, single parenting, and cohabitation have risen precipitously.Benfer, Amy. The Nuclear Family Takes a Hit , Salon.com. 7 June 2001 Nontraditional families (which diverge from "a middle-class family with a bread-winning father and a stay-at-home mother, married to each other and raising their biological children") constitute the majority of families in the United States and Canada today. Shared Earning/Shared Parenting Marriage (also known as Peer Marriage) where two heterosexual parents are both providers of resources and nurturers to children has become popular. Modern families may also have single-parent headed families which can be caused by divorce, separation, death, families who have two parents who are not married but have children, or families with same-sex parents. With artificial insemination, surrogate mothers, and adoption, families do not have to be formed by the heteronormative biological union of a male and a female.

The consequences of these changes for the adults and children involved are heavily debated. In a 2009 Massachusetts spousal benefits case, developmental psychologist Michael Lamb testified that parental sexual orientation does not negatively affect childhood development. "Since the end of the 1980s... it has been well established that children and adolescents can adjust just as well in nontraditional settings as in traditional settings," he argued.Michael Lamb, Ph.D.: Affidavit – United States District Court for the District of Massachusetts (2009) However, columnist Maggie Gallagher argues that heteronormative social structures are beneficial to society because they are optimal for the raising of children. Australian-Canadian ethicist Margaret Somerville argues that "giving same-sex couples the right to found a family unlinks parenthood from biology".Margaret Somerville – In Conversation Recent criticisms of this argument have been made by Timothy Laurie, who argues that both intersex conditions and infertility rates have always complicated links between biology, marriage, and child-rearing.

Heteronormative temporality, a subset of heteronormativity, posits that the ideal societal trajectory involves achieving heterosexual marriage as life's ultimate goal. This ideology imposes societal expectations that encourage individuals to conform to traditional roles within a nuclear family structure: seeking an opposite-sex partner, entering into heterosexual marriage, and raising children. Heteronormative temporality promotes abstinence-only until marriage. Many American parents adhere to this heteronormative narrative and teach it to their children. According to Amy T. Schalet, it seems that the bulk of parent-child sex education revolves around abstinence-only practices in the United States, but this differs in other parts of the world.Schalet, Amy T. Not under My Roof: Parents, Teens, and the Culture of Sex. Chicago: U of Chicago, 2011. Similarly, George Washington University Professor, Abby Wilkerson, discusses how the healthcare and medicinal industries reinforce the views of heterosexual marriage to promote heteronormative temporality. The concept of heteronormative temporality extends beyond heterosexual marriage to include a pervasive system where heterosexuality is seen as a standard, and anything outside of that realm is not tolerated. Wilkerson explains that it dictates aspects of everyday life such as nutritional health, socio-economic status, personal beliefs, and traditional gender roles.

Transgressions

Lesbian, gay and bisexual people According to cultural anthropologist Gayle Rubin, heteronormativity in mainstream society creates a "sex hierarchy" that graduates sexual practices from morally "good sex" to "bad sex". The hierarchy considers reproductive, monogamous sex between committed heterosexuals as "good", whereas any sexual act or individual who falls short of this standard is labeled as "bad". Specifically, this standard categorizes long-term committed gay couples and non-monogamous/sexually active gay individuals between the two poles. Patrick McCreery, lecturer at New York University, argues that this hierarchy explains how gay people are stigmatized for socially "deviant" sexual practices that are often practiced by straight people as well, such as consumption of pornography or sex in public places. There are many studies of sexual orientation discrimination on college campuses.

McCreery states that this heteronormative hierarchy carries over to the workplace, where gay, lesbian, and bisexual individuals face discrimination such as anti-homosexual hiring policies or workplace discrimination that often leaves "lowest hierarchy" individuals such as transsexual people vulnerable to the most overt discrimination and unable to find work.

Applicants and current employees can be legally passed over or fired for being non-heterosexual or perceived as non-heterosexual in many countries. An example of this practice is found in the case of the chain restaurant Cracker Barrel, which garnered national attention in 1991 after they fired an employee for being openly lesbian, citing their policy that employees with "sexual preferences that fail to demonstrate normal heterosexual values were inconsistent with traditional American values." Workers such as the fired employee and effeminate male waiters (allegedly described as the true targets), were legally fired by work policies "transgressing" against "normal" heteronormative culture. Another study indicates that heteronormativity extends to social media platforms as well. While these channels are often seen as "safe spaces" for LGBT individuals, they can also perpetuate heteronormative expectations from work that were previously confined to face-to-face interactions.

Mustafa Bilgehan Ozturk analyzes the interconnectivity of heteronormativity and sexual employment discrimination by tracing the impact of patriarchal practices and institutions on the workplace experiences of lesbian, gay, and bisexual employees in a variety of contexts in Turkey. This further demonstrates the specific historicity and localized power/knowledge formations that give rise to physical, professional, and psycho-emotive acts of prejudice against sexual minorities.

Transgender people Transgender people experience a mismatch between their gender identity and their assigned sex.Stroud District Council "Gender Equality SCHEME AND ACTION PLAN 2007" , defines the state of being transgender as "Non-identification with, or non-presentation as, the sex (and assumed gender) one was assigned at birth."Gay and Lesbian Alliance Against Defamation. "GLAAD Media Reference Guide – Transgender glossary of terms" , "GLAAD", USA, May 2010. Retrieved on 24 February 2011. "An umbrella term for people whose gender identity and/or gender expression differs from what is typically associated with the sex they were assigned at birth.""USI LGBT Campaign – Transgender Campaign" (retrieved 11 January 2012) defines transgender people as "People who were assigned a sex, usually at birth and based on their genitals, but who feel that this is a false or incomplete description of themselves." Transgender is also an umbrella term because it includes trans men and trans women who may be binary or non-binary and also includes genderqueer people (whose identities are not exclusively masculine or feminine, but may, for example, be bigender, pangender, genderfluid, etc.). Some authors also believe that the trans umbrella includes transsexual people, who have transitioned through hormonal replacement therapy and sex reassignment surgery.

Other definitions include third-gender people as transgender or conceptualize transgender people as a third gender,Susan Stryker, Stephen Whittle, The Transgender Studies Reader (), page 666: "The authors note that, increasingly, in social science literature, the term "third gender" is being replaced by or conflated with the newer term "transgender."Joan C. Chrisler, Donald R. McCreary, Handbook of Gender Research in Psychology, volume 1 (2010, ), page 486: "Transgender is a broad term characterized by a challenge of traditional gender roles and gender identity[. …] For example, some cultures classify transgender individuals as a third gender, thereby treating this phenomenon as normative." and infrequently the term is defined very broadly to include cross-dressers.

Some transgender people seek sex reassignment therapy, and may not behave according to the gender role imposed by society. Some societies consider transgender behavior a crime worthy of capital punishment, including Saudi Arabia and many other nations. In some cases, gay or lesbian people were forced to undergo sex change treatments to "fix" their sex and gender in some European countries during the 20th century,The Unkindest Cut | The science and ethics of castrationTuring, Alan (1912–1954) and in South Africa in the 1970s and 1980s.

In some countries, including North American and European countries, certain forms of violence against transgender people may be tacitly endorsed when prosecutors and juries refuse to investigate, prosecute, or convict those who perform the murders and beatings. Other societies have considered transgender behavior as a psychiatric illness serious enough to justify institutionalization.