Is heterosexuality genetic?

[Redalgo]

I reckon that most if not all forms of human sexuality - heterosexual preferences and behaviors included - are the products of a multitude of biological predispositions. Each of the predispositions, for any given individual, may be hard-wired into how the person develops, might go unexpressed unless in some fashion triggered, or can be triggered - in which case interpersonal interactions and social norms may impact whether one opts to accept or make an effort to suppress their desires.

Though it is not a subject I admittedly know much about, my attitude is currently that the influences of "nature" and "nurture" are inseparably interwoven regardless of whether some people deem the outcomes to be right, wrong, normal, immoral, etc.  Expressions of human sexuality are simply that, regardless of whether any of us subjectively consider them to be legitimate. Controversies concerning sexual preferences and behaviors amount to disputes over our customs. There is absolutely nothing innately proper or awry about any critter's biology.