AOL news has an article about a
study that claims to prove that gay parents are significantly more likely to have gay children.
I see several problems with the study as it is presented in the article.
Firstly the methodology seems suspect since it is relying on books in which children of gay parents state that they are also gay. This seems to have several potential flaws, but since I haven't read the methods section, I am not sure the degree to which they are problems, but it definitely something I would think would need to be taken with a chunk of salt.
Secondly, the author is claiming to show that there are environmental factors that influence orientation, but it is not clear that he has ruled out genetic factors. If the children are biologically related to at least one parent, then genetic factors might account for an increase in probability of having gay children.
More importantly I think is a potential misinterpretation where he finds a correlation between gay-accepting groups and cultures and percentage of gay individuals. He seems to be arguing that acceptance of LGBT individuals causes more people to become gay. I think it is far more likely that the individuals would simply be more comfortable acknowledging their orientation, and that some, strictly speaking, bisexual individuals might be more likely to identify as LGBT in an accepting environment, whereas they might identify as heterosexual in a non-accepting environment.
[the junk science tag may not be correct, but it seems to be potentially junk so I thought I would include it. Haven't examined the actual work though]