Stupid Evil Bastard: Twins Studies and Homosexualty
Rated • 1 review • genetics, homosexuality • stupidevilbastard.com
Debunks poorly designed twin study purporting to demonstrate high heritability for homosexuality. I would add a stumble for the most interesting paper he links to directly, a paper by Bearman and Bruckner, but it is a pdf file. The paper, Opposite-sex twins and sexual attraction, describes the results of a study that suggests that in twin pairs (of same sex? not clear to me) of adolescents where at least one member reports same sex attraction, both twins report same sex attraction 6.7% of the time when the pair is monozygotic (identical twins) and 7.2% of the time when the pair is dizygotic (fraternal twins). For full siblings (not twins?), the corresponding concordance rate is 5.5%. The paper thus suggests rather conclusively that the genetic component to early same sex attraction is weak.

