Nature's Choice by Cheryl L. Weill

Author:Cheryl L. Weill [Weill, Cheryl L.]
Language: eng
Format: epub
Tags: Psychology, Human Sexuality, Science, Life Sciences, Human Anatomy & Physiology, Social Science, LGBTQ+ Studies, Gay Studies
ISBN: 9780789034748
Google: HhBjTzbhjhQC
Publisher: Taylor & Francis
Published: 2009-01-15T05:40:53+00:00

Auditory Evoked Potentials

Auditory evoked potentials (AEP) are brain waves produced in response to click stimuli and recorded using scalp-electrodes, a kind of sound electroencephalogram. Sex and ear differences exist in certain AEP measures in infants and adults (McFadden and Champlin, 2000). A study of AEPs in heterosexual and homosexual individuals (57 lesbian and bisexual women, 49 heterosexual women, 53 gay and bisexual men, and 50 heterosexual men) revealed that selected measures were sexually dimorphic. For these measures (specific amplitudes of selected wave peaks and selected latencies), the values for lesbians were intermediate between those of heterosexual women and heterosexual men and thus appeared masculinized on these measures. In contrast, the measures for gay men were shifted even further from heterosexual women than were heterosexual men and thus appeared to be hypermasculinized on these measures.

In his review of OAEs and AEPs McFadden (2002) identified the following observations: (1) there are sex and ear differences in OAEs and AEPs and hearing sensitivity, (2) these sex and ear differences exist in newborns and adults, (3) OAEs and AEPs appear to be reasonably stable traits throughout life, (4) females from opposite-sex twin pairs have masculinized OAEs, (5) lesbians and bisexual women have masculinized OAEs and AEPs, and (6) gay men have hypermasculinized AEPs, but comparable OAEs relative to heterosexual men.

McFadden (2002) suggests that the finding that OAEs and some AEPs exhibit sex differences and that these sex differences are present in adults, young children, and newborns, implies that these differences are the result of mechanisms operating prenatally and differentially in the two sexes. Furthermore, the differences in OAEs observed in females of opposite-sex twins and in the OAEs and AEPs of heterosexuals and homosexuals exist at birth. If this is true, then it is reasonable to conclude that the sex differences seen in the OAEs and AEPs of newborns is the result of the same mechanism known to be responsible for numerous other sex differences in body, brain, and behavior, namely differential exposure to androgens during prenatal development. This leads to the viewpoint that greater exposure to androgens during prenatal development leads to a weakening of the cochlear amplifiers, which produces a weakening of the OAEs and a small loss in hearing sensitivity and also leads to effects on various auditory nuclei concerned with hearing sensitivity, AEPs, and possibly other auditory characteristics or abilities. This prenatal androgen exposure explanation provides a general overall perspective that appears consistent with all of the auditory results considered in the review.

The author took care to note that the findings he reports are all correlations and do not demonstrate a cause-and-effect relationship. The observed results could easily relate to a causal factor, other than androgen exposure, that was also responsible for the person’s membership in the group of interest, that is, males versus females, lesbians versus heterosexual women, female twins of opposite-sex twin pairs versus females of same-sex dizygotic twin pairs, and gay men versus heterosexual men.

McFadden goes further and poses three questions that need to be addressed to

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