A lot of what is considered traditional femininity is all about attracting men. So when you're unconcerned with attracting men you are going to be less feminine than women who are because one of the driving factors of femininity just isn't there. Femininity isn't innate, it's socialization.

Military and sports aren't natural, neither are fashion or interior design. You can't say someone has a particular sex of brain based on things they like that are completely unnatural and unrelated to sex.

"There's no obvious reason why sexual orientation should be associated with how masculine or feminine one is, but it is in our species. And it probably has to do with the causes of sexual orientation and early effects of hormones on the brain," Bailey said.

Because masculinity and femininity are very much tied to attracting the opposite sex. That's the main driving factor for them. You remove that factor and people are just going to do what they like. There'd probably be a lot more straight women into sports if straight men suddenly found that to be attractive and feminine and women had that drilled into their heads since they were babies.