What makes people gay, lesbian, bisexual, or heterosexual? And who cares? These are the twin themes of Queer Science, a scientific and social analysis of research in the field of sexual orientation. Written by one of the leading scientists involved in this research, it looks at how scientific discoveries about homosexuality influence society's attitude toward gays and lesbians, beginning with the theories of the German sexologist and gay-rights pioneer Magnus Hirschfeld and culminating with the latest discoveries in brain science, genetics, and endocrinology, and cognitive psychology. Research into homosexuality exemplifies both the promise and the danger of science applied to human nature. LeVay argues that the question of causation should not be the crucial issue in the gay-rights debate, but that science does have an important contribution to make. It can help to demonstrate that the traditional and still prevalent view of homosexuality - as a mere set of behaviors that anyone might show - is inadequate, and that gays and lesbians are in a real sense a distinct group of people within the larger society with a privileged insight into their own natures.