A new study in Canada points to evidence that having older brothers increases a male’s chances of being homosexual. Researchers are continuing their attempts to isolate a cause for homosexuality, which includes answering the nature vs. nurture question. This particular study comes down of the nature side, the theory being that mothers have some sort of memory for male gestations or births that affect sons born afterwards.
This area of inquiry has never made sense to me. If there is a certain incidence of a particular trait in humans, say blond hair or freckles, even though there may be observable predictors, they usually fall well short of being mechanisms we could control. Genetic defects are a different category, and it makes sense to me to try to limit them. But homosexuality isn’t a defect, at least to those who accept it as a regularly occuring variation (behavioral, genetic, or otherwise).