Homosexuality

[Free Palestine]

Could it not be unrelated to genetics, yet at the same time not be a free choice? Seems like there is a world of possibilities you're not offering.

It's possible.

There might be some reason relating to socialization in early childhood that causes people to become gay.  In fact, I think that is definitely the cause of transgenderism.  Neither are "choices," but nor are they, in my belief, genetic.

[Free Palestine]

The predisposition to same-sex attraction is probably at least in part genetic, along with some element of socialization, any activity that could affect hormone levels, etc.

But, to act upon those attractions is not genetic at all. People also have the ability to not engage in a sex act or to enter into a certain relationship. So if we take homosexuality to be an act rather than an attraction (the word 'homosexuality' may be ambiguous in this respect, though I haven't met many celibate people who experience same-sex attraction who call themselves homosexuals so I am taking it to imply that one has engaged in said acts and is not celibate), then it must be a choice as long as we accept that we have the ability to make choices, ie. free will. If we have no free will then this is all a moot point anyway, so I'd consider "lifestyle choice" to be a more representative reflection of my view than "genetic" but that I'd rather select "Both" if I could.

Breathing and eating should also be classified as "lifestyle choices" then.

What we eat is largely a lifestyle choice, as is how much we eat.  It isn't absolute free will, but it is close.

That's actually probably untrue.  Obesity has high heritability, somewhere around .80 (higher than height, even!).  A lot of that is likely due to different food preferences which might be essentially hardwired.  I'm somewhat of a supertaster, for example, and my eating habits reflect that; consequently, I'm not overweight.  It's hard to imagine the number of taste buds on my tongue not at least partially being a product of genetics

That's not to say you can't help your weight entirely, of course.  But most people don't try to do things completely out of sync with what their body tells them.

I think it has to do with fat parents passing on their unhealthy eating habits to their kids, who become fats themselves, rather than anything genetic.