I don't think attraction is exclusive to physical appearance or genitalia.
I don't think attraction is exclusive to physical appearance or genitalia.
But we also know that mental habits, repeated for years, become deep visceral reactions. And society programs our unconscious attitudes in a way that's difficult to appreciate simply through conscious introspection.
It's actually hard to know what you'd be attracted to, if you lived in a society that truly accepted/encouraged same-sex attraction. Maybe you'd be the same. Maybe you'd have dated guys once or twice, but ended up straight. Maybe you'd have five kids with a male partner. It's hard to say - it's an experiment that hasn't been run.
In those studies -- many by Meredith Chivers -- there is a clear differentiation in men (though not in women) in arousal that distinguishes heterosexual and homosexual patterns of attraction.