If I think about it, people are born as infants. They are "blank slates" when it comes to their life and behavior where they can/do have genetic "predispositions" to be more or less inclined towards certain behaviors and that it is then the life experiences that occur as the individual grows that influence their responses and reactions to external situations and opportunities. An infant can have an inherited tendency (or a higher likelihood) of becoming chemically dependent, or a risk-taker, or a thrill seeker, or a being hesitant/shy, a high/low metabolism, be more likely to develop allergies, have a stronger immune system, all sorts of things that "lean" in one way or another as to what their later life will have them facing and dealing with as they grow and age. Do I believe that sexuality is genetically pre-determined? No, at least not completely. I believe that just like my genetics made it very likely (and eventually true) that I would lose the hair on my head, that some physical events are "more genetic" than some personal/social outcomes, that even those social outcomes are a matter of a genetic "nudge" that is then profoundly affected by life events, environment, and how the person grows and develops. The idea that sexuality is a genetic "pre-set" and there are no other factors involved doesn't seem (to me) to assign enough credit, power and influence to the individual, their environment, their life experiences, their environment and so on. But I am also not able to agree with the idea that "it's a choice". There are so many aspects of who each of us are as individuals that are not a matter of "I make the conscious decision to be ______" No one can make the choice to be smart, or tall, or athletic, or healthy, We are a sum of our genetics, our experiences, our memories, our conscious and non-conscious thoughts. Someone can make an effort to be kind, gentle, mean, rude, hostile, sarcastic, outgoing, withdrawn, and so on, but their conscious choice is only part of the process and choice alone does not determine if they are going to be what they want (or choose to be). Other factors can "make it happen" despite their conscious desires.