I have two questions.

God I want them to sandwich me with their bodies

>>6884817
>identical and fraternal twins
>identical twins can separate sooner or later in development
It probably has something to do with that, OP.

>>6884817
50% is pretty high, even for identical twins. It's the same overlap as for schizophrenia which is considered to have a significant genetic component to it as well. I think 60% of identical twins share autism. Which still leaves 40% who don't.

Genetics aren't as simple as we'd like, there are a lot of elements at play.

>>6884837
But do identical twins separate in development during the prenatal period?

>>6884847
Schizophrenia has a lot of social causes, but scientists say, that sexual orientation can only be innate. But I have seen the opinion, that psychological and social factors should also be taken into account along with genetic and hormone influence, at least twice.

>>6884871
You can have different hormone exposure even if you share a womb.

>>6884871
Even so, schizophrenia clearly does have a genetic component. It occurs in some families more than others. Also, I believe that there is headway in researching the relationship between environment and gene expression. The two aren't as independent as it was once believed.

>>6884876
And how is it actually possible?