[Does so]

In general terms they are exposed to the same factors day after day after day. This is their life up until 12 or 13.

The better study would have been to examine the lives of twins who had been separated before 12 or 13. (There are such studies, but not for homosexuality).

[DoughtyOne]

Good point.

Others have made some good points about the idea that even in similar circumstances kids don’t get the same experience. I’m somewhat sympathetic to that concept as well.