What we know : the black box -- The black box -- What we don't know : opening the black box -- The debate : definitive proof that homosexuality is biological -- The debate : definitive proof that homosexuality is not biological -- How to look at a brain -- Biological archaeology -- Genetic grammar 101 : a crash course -- The gay gene : the discovery of Xq28 -- What does "genetic" mean? -- How genetic surgery can change homosexuality to heterosexuality -- The knowledge of good and evil -- Notes -- Glossary -- Index.