Hines Melissa
Department of Psychology (Social and Developmental), University of Cambridge, Cambridge, UK.
J Neuroendocrinol. 2009 Mar;21(4):437-8. doi: 10.1111/j.1365-2826.2008.01788.x.
Why are there sex differences in human behaviour, and why do some of us behave in sex-typical ways, whereas others do not? For instance, why are some girls 'tomboys', preferring to play with boys and boys' toys? Similarly, why do people differ in sexual orientation, with some interested in partners of the opposite sex, while others are interested in partners of the same sex? Testosterone during prenatal development appears to be part of the answer.