Complex sentence: LeVay discusses scientific research on sexual orientation conducted since his 1991 study of the hypothalamus, writing that the research supports the conclusion that sexual orientation is a product of the interactions between sex hormones and the developing brain, which predispose people's minds toward masculinity or femininity.
Split into simpler sentences: LeVay discusses scientific research on sexual orientation conducted since his 1991 study of the hypothalamus. He writes that the research supports the conclusion that sexual orientation is a product of the interactions between sex hormones and the developing brain, which predispose people's minds toward masculinity or femininity.