Having said this, Buss insists that male homosexuality is an extension of man’s evolutionary heterosexual behavior: both of short and long term mating strategies. The two men require similar characteristics in their mates e.g. youth, good looking and are identical in their mating strategies except for one, that the homosexual man is attracted to men instead of women.
Hamer discussed this difference as a possibility for a gay gene in his 1993 study. Although McKnight has pointed out that even though with there being a genetic difference between male homosexuals and heterosexuals, it is still largely an area that needs further research. “This indirect evidence of a genetic basis for at least some forms of male homosexuality is supported by three decades of research reporting chemical and anatomical differences between straight and gay men.” (McKnight, 1997) On further experimentation, McKnight writes on Hamer’s theory of the gay gene, “At this preliminary stage we have no found support for Hamer’s suggestion…” (McKnight & Malcolm, 2000) He further states, “Our analysis failed to find a distinctive reproductive pattern, which might emerge with a larger sample size, but if repeated would suggest that the genetic mechanism is autosomal.” (McKnight & Malcolm, 2000)
Buss writes that, “Many men who prefer women as mates may nonetheless substitute a man as a sex partner, either because of an inability to attract women or because of a temporary situational constraint that preludes access to women…” (Buss, 1994) This is true in the case of prisons or forcefully held captives but not always true of the large population of gay men in society today. Buss (1994) further continues that, “Male homosexuals and male heterosexuals seem to have indistinguishable mating preferences, expect with respect to the sex of their preferred partner.”
Evolutionary Problem / Solution regarding Homosexuality
There are two main evolutionary problems with homosexual behavior that emphasize its extinction. Still, keeping conflicting motives in mind between evolution and homosexuality, the gay male introduces himself as a tool for understanding evolutionary motivations.
1. Procreation
With similar mating strategies between male heterosexuals and homosexuals, it becomes increasingly complicated to understand why the homosexual man has survived and continues to do so. The two men (straight & gay) share in common certain characteristic requirements of their mates. The straight male can produce children and therefore increase his evolutionary fitness. On the other hand, the gay male cannot reproduce. There are obvious disadvantages of homosexuality that natural selection would eventually select out such as the inability to procreate. Evolutionary advantage works to increase the average growth of the species and the homosexual male cannot be used as a catalyst.
Yet, according to the Census of 2001 there has been a rise of gay population across the United States. McKnight (2000) exclaims in his paper that “… there is a real puzzle here and it goes to the heart of sexuality as no sex equals no children. While sex has more purposes than reproduction, begetting offspring is the ultimate end game – a relationship more clearly understood in an age of unreliable contraception.” He calls this phenomenon ‘Child Hunger’. It would according to evolutionary theorists be baffling to understand homosexuality in face with the fact that it results in no children and therefore is not child hungry yet it not only exists but increases rapidly. “Male homosexual orientation is particularly problematic as it is a behavior that is clearly a reproductive liability.” (Weinrich, 1978 as cited in McKnight, 2000)
2. Sexual Variability
The idea of normalcy in terms of sexual behavior globally has changed drastically over and over again through the course of history. The categorization of men as homosexuals and heterosexuals labels, confines naturally sexual deviations into one or the other group. “That many men having homosexual experiences as part of their development was deeply disturbing to the mid – twentieth century, does not disguise that similar studies report similar findings at the end of the millennium. Kinsey (Kinsey, Pomeroy and Martin 1948) may have lifted the lid on the realities of human sexual experience but a half-century of further research merely confirms how plastic our sexuality is.” (McKnight, 2000) This plasticity of sexual behavior increases the likelihood that homosexual behavior although conflicting with evolutionary psychology indeed is a process of increasing sexual deviations and therefore the possibility of natural selection in sexual experience. Through gay behavior the human male is able to explore all possibilities of sexual behavior that would excite and entice him into an evolutionary advantage over men who are not as sexually active.
Origins of Homosexuality
According to Buss (1994), “the origins of homosexuality remain a mystery.” Yet, the alarming increase in males who prefer men as their mates seem as if the origins of homosexuality similar to that of heterosexuality is the same. Sexual selection provides for variants in sexuality not unlike natural selection. “If you accept that human sexual orientation is diverse and variable and above all plastic, then there is a certain sympathy for Murphy’s view: It is hard to see that there is any … reason to study the origins of behavior that is morally, medically, psychologically (and perhaps even religiously) aproblematic.” (Murphy, 1990 as cited in McKnight, 2000) Nonetheless, evolutionary theorists have studied the origins of homosexuality in great detail attempting to find a key difference between straight and gay men.
Biological Influences as origin of homosexuality:
Alexander (2000) initiated research in finding structural and functional differences between homosexual and heterosexual males. He writes that Burnham in 1977 had noted that females have smaller brains than males and therefore women were less intellectual then men. “Although it is true that male brains are somewhat larger … than female brains, this is the first example of structural difference that does not evince a measurable behavior difference.” (Alexander, 2000) Similarly, the fact that there might be some structural differences between straight and gay men it does not account for the fact that there would be core differences in sexual preferences.
Alexander (2000) further noted that the Committee for the Study of Sex Variants in New York City in the 1930’s studied a homosexual population using various “psychological tests, hormonal measurements and physiological measurements of the genitalia and other body parts including skull circumference.” The authors of the study realized that there was no conclusive proof that any individual may be a so called “sex variant” and or might be more prone to homosexual behavior than the next person. (Henry, 1948 as cited in Alexander, 2000) These inconclusive studies provided for further research that might shed light on biological aspects of homosexuality. “The early 1990’s was a remarkably productive period of time for research into sexual dimorphism of brain areas.” (Alexander, 2000)
If there would be any biological connective that was found then it would also be possible to understand the motivations for homosexuality and categorize it in terms of evolutionary advantage, if any, by studying the population. This was not the case. Although there were studies done by researchers such as Allen and Gorski in 1990 and 1991 “Taken together, these finding indicate that sexually dimorphic structures can be found in many different areas of the brain.” (Alexander, 2000)
A foremost breakthrough in these studies was by Swaab and Hofman, 1990 in which distinct differences were noted. The Suprachiasmatic nucleus of vasopressin-containing neurons was double in homosexual men when compared to heterosexual males. (LeVay, 1991) Further studies compared Swaab’s findings with that of Allen and Gorski that concluded that the “anterior commissure (found to be sexually dimorphic – larger in females) also was different according to sexual orientation such that it was larger in homosexual males compared with both heterosexual males and females. Since the homosexual group did not fall between or have identical size to the female group, this outcame gave rise to another working hypothesis of a third sex – the gay sex.” (Alexander, 2000) Nonetheless Breedlove’s 1997 study proved that this hypothesis was false. Breedlove concluded that there was no evidence that the outcome mentioned before was not an effect rather than a cause. “It is possible that differences in sexual behavior cause, rather than are cause by, differences in brain structure.” (Breedlove, 1997)
Since there is no actual biological root that explains homosexuality, it is possible that similar to heterosexuality, it was used as a tool to better achieve fitness. Male homosexuality, in my opinion can be explained in evolutionary terms as follows:
- Sex used as a tool for reciprocal altruism
Women have evolutionarily used sex as a means to get resources and guarantee a mate through promising sex. Homosexuality, similarly, in men can be used to coopt resources and guarantee a long term partner that would invest resources.
- Adoption of Children
Homosexual men are also an added advantage in a social structure that produces excess children with little life expectancy without adequate domestic care. They can provide as means of adoption and surrogate parents an alternative to what may be now considered a family.
- Reduction of Same Sex Conflict
Homosexual behavior might also be responsible for creating coalitions amongst men that would eventually decrease male – male aggression and therefore increase evolutionary advantage for the species by an average.
These three suppositions go without any data to support them and I would find it interesting to look at studies that would explore homosexuality as an added advantage for evolutionary success.
References:
Alexander, J. E. (2000). Psychology, Evolution & Gender, 2 (3), 241- 252. Retrieved May 3, 2005, from Academic Search Premier ( AN 13136569).
Buss, D. E. (1994). The Evolution of Desire: Strategies of Human Meeting. New York: Basic Books
McKnight, J. (2000). Editorial: the origins of homosexuality. Psychology, Evolution & Gender, 2 (3), 223- 228. Retrieved May 3, 2005, from Academic Search Premier (AN 4318964).
McKnight, J. & Malcolm, J. (2000). Is male homosexuality maternally linked?. Psychology, Evolution & Gender, 2 (3), 229-239. Retrieved May 3, 2005, from Academic Search Premier (AN 4318963).
Census finds 600,000 same-sex couples Tom Musbach, Gay.com / PlanetOut.com Network published Wednesday, August 22, 2001