@lololulu19:
I am sure there is no single reason why people are gay, but here is one reason I think is valid.
It is a FACT that in families with multiple sons, the YOUNGEST son is far more likely to be gay than the older ones.
Being a youngest son, I have an explanation for that.
Parents typically pay a LOT of attention to their first born child.. and lesser for each child after that.
Quite often, the last child was not wanted in the first place - but was the result of thinking that the parent's child bearing years were over with, but they got a SURPRISE.
I think the last sons are often neglected. I certainly was. Both of my older brothers were encouraged to be in Boy Scouts, drum & bugle corps, etc. I was pretty much ignored, and left to rot at home. Whenever my parents would go out with my older brothers to a restaurant or to the beach, they would leave me at home, with no baby-sitter.
I think that when a child is neglected, he realizes that it is more important to have a friend than it is to have a family that can't be depended on.
For reason I think it far more beyond the family conditions and attention one receives as a child. I think there some more at the level conception when parents were in the act of making baby. Requires more scientific consideration, how does that act of making baby can affect the sexuality of the baby.