Evaluate the evidence for prenatal hormonal influences on the development of sexual orientation in humans by
In an attempt to evaluate the effects of prenatal hormones on the development of sexual orientation (in humans) it is important, first, to be clear what sexual orientation is. Once defined the evidence supporting such a claim (as well as other biological and social theories) can then be investigated. Sexual orientation can be defined as ‘tastes in sexual partners’ (Gross, 1996, cited in Gross, 1996). ... The hypothesis that hormones wire the brain for sexual orientation (during a critical period) rests largely on observations made in rodents. ... The evidence, so far, implies that hormones do influence sexual orientation and that homosexuality is simply the result of insufficient androgens in males and excess amounts in females. ... Kinsey, Pomeroy, and Martin (1948, cited in Gleitman, Fridlund, Reisberg, 1999) found that administration of androgens to gay men did enhance sexual drive but it did not change its direction, their interest was still towards men. This research is vital in understanding that it is hormonal influences during pregnancy that is important and not the effects of them during adulthood. Thus hormones can only influence sexuality during the time when the neural circuits in and around the hypothalamus, a region believed to regulate sexual behaviour, become sexually differentiated (i. ... Gunter Dorner (1980, cited in Le Vay, 1996) suggested what might cause hormonal disruption. ... Later, when the male offspring were ‘tested’ for sexual responses with (estrous) females they failed to perform. Ward hypothesised that prenatal stress syndrome altered androgen levels and brought about the result. ... If this logic were applied to humans it would imply that only one (of the two engaged in sexual intercourse) is homosexual and such dependency relied only on the position they assume. ... Androgens are necessary for the development of external genitalia thus individuals affected by such a deficiency do not develop correctly, in that area, and so need corrective surgery. ... However, interestingly, Ehrhardt and her colleagues (1985, cited in Pinel, 2000) found that diethylstilbestrol (a synthetic estrogen) could also manipulate sexual orientation. ... Thus the conclusion drawn was that such prenatal exposure induces homosexual and bisexual tendencies albeit the effects are weak, nonetheless it shows how hormones are somewhat influential. Suffice to say it could be argued that hormones do seemingly influence sexual orientation and thus bring about masculinized and feminised brains. ... This region has long been implicated in the regulation of sexual behaviour. ... Interestingly the differences found are also said to result from early exposure to androgens (thus supporting the prenatal hormonal hypothesis).