Chapter 9 - Preference for same sex partners in the human

Abstract

This chapter focuses on homosexuality in the human. All behavior is caused by activities in the nervous system. Likewise, when a human male chooses to approach a woman for executing sexual responses, he does so because of activities in the central nervous system. If he chose to approach another man instead, that would also be caused by activities within the nervous system. In some way or another, stimuli emitted by the sexual incentive, regardless of whether it is a man or a woman, modify the firing rate of neurons somewhere in the brain, and the result will be approach. The nervous processes underlying the approach behavior is called its biological cause or biological basis. In the search for a biological basis for approach to individuals of one's own sex, the term “biological basis” does not have that meaning. Instead of referring to a set of nervous responses to particular stimuli, it refers to constant predispositions of the nervous system causing it to respond more to stimuli emitted by one's own sex than to stimuli emitted by the opposite sex. These constant predispositions may be caused by genes exclusive to people responding to the own sex more than to the opposite, or by endocrine events during brain differentiation, again exclusive to those responding to individuals of the own sex, or by particular blood concentrations of gonadal hormones in adulthood. The search for an endocrine, genetic, or structural basis for same-sex preferences has yielded conflicting results.