Describe the factors that underlie sexual orientation.

Question

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Answer 1

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Considerable research suggests that biological and genetic factors underlie sexual orientation. Studies of identical twins have found that when one twin identified himself or herself as homosexual, the occurrence of homosexuality in the other twin was higher than it was in the general population. Such results occur even for twins who have been separated early in life and who therefore are not necessarily raised in similar social environments. Furthermore, some research suggests there is an area on the X chromosome associated with homosexuality. Hormones also may play a role in determining sexual orientation. For example, research shows that women exposed to DES, or diethylstilbestrol, before birth (their mothers took the drug to avoid miscarriage) were more likely to be homosexual or bisexual. Further evidence suggests that differences in brain structures may be related to sexual orientation. For instance, the structure of the anterior hypothalamus, an area of the brain that governs sexual behavior, differs in male homosexuals and heterosexuals. Similarly, other research shows that, compared with heterosexual men or women, gay men have a larger anterior commissure, which is a bundle of neurons connecting the right and left hemispheres of the brain.

Though research is not conclusive in pinpointing the specific cause, it seems likely that some inherited or biological factor predisposes people toward homosexuality. In contrast, little evidence suggests that sexual orientation is brought about by child-rearing practices or family dynamics. Although proponents of psychoanalytic theories once argued that the nature of the parent-child relationship can produce homosexuality, research evidence clearly does not support such explanations.