Studies in bonobos point to there being a very strong genetic component in fact. Bonobos and chimps being our closest relatives I think the biological evidence is more compelling than you think.
I've lost the reference but it was a study of sexual behavior in bonobos and their "non-discriminatory" attitude and practices. Bonobos of course being famous for their sexual proclivities and chimps being famous for their violent proclivities.
If you google relevant keywords I'm sure it will turn up.
Ok... but were certain bonobos more likely to be non-discriminatory than other bonobos based on genetics?
Yea there's tons of studies talking about bonobos sexuality. I did a google search and nothing about a specific set of genes causing a certain sexual behavior in a segment of the bonobo population.
What you are talking about sounds like general behavior in an entire population. And if that's the case then why aren't all humans pedophiles?
Edit: As a counterpoint this is the first thing I found when searching for 'bonobo' 'gene' 'sexuality'
