i will try and respond but i fear we are boring everyone else...

I am familiar with Bailey and Pillards study and there are significant problems with it. First, as i have said previously, if homosexuality is genetically determined, why did only 52% of the identical twins share the same sexual orientation? How about the other 48% of the twins who differed in their sexual orientation? How do we account for them? Second and more importantly, the study was based upon a sample of twins which was not random. As critics have pointed out, Bailey and Pillard did not rule out the possibility that they had preferentially recruited twins where both brothers were gay by advertising in homosexual newspapers and magazines rather than in periodicals intended for the general public. Indeed, it now appears that preferential recruitment did occur in the 1991 study – a more recent 2000 study by Bailey and his colleagues, using volunteers recruited, not from the gay community but from the Australian Twin Registry, reveals that only 20% and not 52% of identical twins share the same homosexual orientation. This is not as significant a difference between identical and fraternal twins as earlier reported. Thus, as the authors of the 2000 paper conclude, it is very difficult to distinguish the genetic from the environmental influences on sexual orientation.