Thank You, Bad Science

http://news.yahoo.com/s/ap/20060626/ap_on_he_me/sexual_orientation

So, assuming that the article is accurate (which may not be the case), a study found that men with multiple older biological brothers were more likely to be homosexual. They also found that this did not apply to men with multiple older stepbrothers.

They then conclude that the effect must be biological, because the environment was the same.

Did they really just assume that families that have undergone divorce and remarriage are the same environment as families that stayed intact? (Yes, there are some divorces and remarriages that give multiple biological brothers, but that's going to be a minority.)