Is Being Gay a Choice? The Biological Basis of Homosexuality

Introduction

Being gay is not a choice. This position is supported by a range of factors and research studies suggesting that homosexuality is not necessarily socially determined or socially influenced. There is a substantial body of evidence — including personal testimonies — that strongly suggests a valid and real biological basis for sexual preference in human beings, as well as in the natural world.

The stance taken in this paper is that being gay is very often biologically determined, and that a person who is gay is so because of intrinsic genetic factors that have relatively little to do with social or cultural influences, although these may play a role in some instances. This view will also necessarily take into account the opposing arguments against the biological thesis of homosexuality.

Overview of the Nature vs. Nurture Debate

The debate about the causes — or rather the origins — of homosexuality is often framed in terms of the nature versus nurture debate. This is a contentious issue in the scientific community, concerned with whether biology or environment is the determining factor in human behavior. As Caramagno (2002) asks:

"Is it even possible to decide which aspects of sexuality are innate and which parts are learned when biological systems are so responsive to environmental conditions and when the hypotheses science tests contain concepts that are themselves socially constructed?" (Caramagno, 2002, p. 97)

This question raises important issues about how we perceive and understand biology itself. Nevertheless, the weight of available evidence tends to support the view that biological determinants are pivotal in shaping sexual preference. While one can debate nature versus nurture at length, there is compelling evidence to suggest that homosexuality has a strong biological grounding. Social aspects and components of sexual preference exist, but the biological substratum should be acknowledged as the fundamental origin of sexual preference and homosexuality.

This view is supported not only by scientific data but also by the statements of many gay individuals who express their sexual preferences publicly, or who "come out of the closet." In the literature, one frequently encounters statements such as "I was a man trapped in a woman's body" — or vice versa. Such statements suggest that nature, rather than nurture, is the primary determining factor in homosexuality, indicating a deeper biological or genetic propensity rather than a social one. This is further supported by scientific findings — for example, the observation that homosexuality appears more prevalent in certain genetic lines and is inherited within certain families more than others.

Biological Determinants of Sexual Orientation

While many scientists and psychologists argue that homosexuality is not "inborn" but is a result of social conditioning, there is also substantial scientific and biological evidence pointing to a biological basis for sexual preference. The idea that sexual preferences are innately biological has been recognized by biologists since the late 1800s. "Theories about instincts, drives, unconscious impulses, hormones, interhemispheric brain function, and evolutionary aims were proposed by various scientists, including Darwin, Krafft-Ebing, Freud and Ellis." (Caramagno, 2002, p. 97)

These earlier scientific perspectives also tended to emphasize the biological basis of homosexuality. For example, Magnus Hirschfeld noted that "both male and female sexual orientations tend to run in families (gay men have more gay brothers and lesbians have more lesbian sisters than heterosexuals do)" (Caramagno, 2002, p. 97). This central observation supports the view that sexuality is biologically determined, and it has since been extended by more recent research. By contrast, sociologists and others maintain that sexual behavior is learned rather than innate.

More recently, Simon LeVay's article "A Difference in Hypothalamic Structure between Heterosexual and Homosexual Men" (1991) emphasized the biological component of sexual preference. This research suggests that genes "might affect sexual orientation by producing enzymes and proteins that determine the structure and function of the brain" (Caramagno, 2002, p. 101). LeVay found that "one of four particular groups of cells (called INAH 1, 2, 3, and 4 for the interstitial nuclei of the anterior hypothalamus) of the brain was twice as large in heterosexual men as in homosexual men or in women" (Caramagno, 2002, p. 97). This led to the conclusion that "INAH [3] is dimorphic with sexual orientation, at least in men, and suggests that sexual orientation has a biological substrate" (Caramagno, 2002, p. 97).

In autopsies of 41 people — 19 retrospectively categorized as gay men, 16 as straight men, and 6 as straight women — LeVay measured the size of a group of cells in the hypothalamus. It was already known that two of the cell groups were larger in men than in women, and LeVay found the same difference in size when comparing heterosexual men to homosexual men (Caramagno, 2002, p. 101). This research therefore establishes a direct connection between physical aspects of the brain and sexual orientation.

This controversial research is also supported by findings from geneticists. Hamer, in collaboration with Hu, Magnuson, Hu, and Pattatucci (1993), conducted extensive research on the so-called "gay gene." Their research found that a genetic marker on the Xq28 chromosome had been isolated that "correlates with male homosexuality" (Brookey, 2001, p. 171). This finding points toward genetic and biological foundations of human homosexuality. Advocates of gay rights have argued that this research proves sexual orientation is not chosen, and that gay people should therefore not face discrimination because of their sexuality (Brookey, 2001, p. 171). However, the discovery of the "gay gene" has generated considerable debate, with critics emerging from both social and scientific disciplines.

Further evidence can be found in the field of sociobiology. In brief, this field applies evolutionary theory to social behavior and holds that homosexual genes predominate in certain situations when society and evolution require it. In some societies, for example, gay men assume roles traditionally associated with women. One explanation offered is that this is necessary "to improve their siblings' procreative success by assisting in the care of children" (Brookey, 2001, p. 171). The logic is extended as follows: by foregoing reproduction and caring for the offspring of siblings, homosexuals contribute to the survival of their own genes by improving the chances that those genes will live on through their relatives' offspring (Brookey, 2001, p. 171).

Research into animal behavior has also shed light on the biological foundations of sexual preference across species. "Sexual diversity has been found in every geographical location and in every major animal group, including monkeys, dogs, cats, rats, goats, horses, elephants, mice, lions, baboons, apes, and porpoises" (Caramagno, 2002, p. 98). Specific documented behaviors include male orangutans copulating anally, male dolphins pairing off and avoiding females even during courting season, and male squirrel monkeys and chimpanzees engaging in full mouth-to-mouth kissing (Caramagno, 2002, p. 98).