Hand preference in homosexual men.

The present study examined the distribution of hand preference and its relationship to immune system functioning and performance on neuropsychological tests in a sample of 993 homosexual men from the Multicenter AIDS Cohort Study comprising 502 HIV-1 seronegatives, 436 asymptomatic HIV-1 seropositives, and 55 men with diagnoses of AIDS or AIDS Related Complex. The prevalence of left-handedness in all of the groups (13.1-14.5%) was consistent with prior published reports of prevalent left-handedness in the general population. The distribution of hand preference scores (on a 5-item self-report questionnaire) was J-shaped and shifted to the right as in the general population. There were no differences between right- and left-handers in the immune system parameter of CD4 counts, nor was there any increase of self-reported allergies among the left-handers. We found a significantly larger number of 'outliers' on the neuropsychological measures for left-handers than for right-handers, both for HIV-1 seronegatives and seropositives. These results failed to replicate Lindesay's (1987) report of a leftward shift in manual preference among homosexual men, and failed to support Geschwind and Galaburda's (1985b) hypothesis of a link between homosexuality, handedness and autoimmune disorder. The differences between right- and left-handers on neuropsychological measures, independent of HIV-1 serostatus, are discussed in terms of Satz's (1972) model of pathological left-handedness.