Biology and sexual orientation INAH3 weight for the heterosexual male brains was significantly larger than for the heterosexual female brains, while the results for the gay male group were between those of the other two groups but not quite significantly different from either. The neuron count also found a male-female difference in INAH3, but found no trend related to sexual orientation. A 2010 study, Garcia-Falgueras and Swaab asserted that "the fetal brain develops during the intrauterine period in the male direction through a direct action of testosterone on the developing nerve cells, or in the female direction through the absence of this hormone surge.
Sexual bimaturism Sexual bimaturism Sexual bimaturism describes a difference in developmental timing between males and females of the same species. Sexual bimaturism can result in sexual dimorphism, but sexual dimorphism could also develop through differential rates of development. In many insects, the larval period of females is longer than that of males, and as a result of this extended growth period, these female insects are larger than their male conspecifics. Male simian primates are generally larger than females of the same species due in part to extended growth periods. Gorillas demonstrate a particularly high degree of sexual bimaturism. Bimaturism can refer to