[hellbender]

I've seen some "butch" lesbians who definitely look as if they have too much testosterone for a normal female. Since testosterone helps muscles grow and increases aggression, higher levels give some women an edge in sports. Think of the disproportionate number of female athletes who are gay: Billy Jean King, Martina Navratilova (more muscle and less fat that a typical woman)...

As for the males, there are gay males who look and act very macho.

[freespirited]

Congenital adrenal hyperplasia causes girls to be exposed to excessive levels of testosterone in utero. Even though the condition is typically corrected at birth, when diagnosis is made, these females are much more likely to have male interests and behaviors (eg more interested in sports than average girl) and be lesbians once old enough to have a sexual preference.

For males, however, I think any biological basis is probably something other than sex hormones.

[scripter]

I think most of us have seen those whom you describe. We’ve seen effeminate heterosexuals who outnumber effeminate homosexuals and quite a few groups. What we do see in study after study is that environment is always the largest factor in determining our sexuality.