Almost anything by Sam Harris is worth listening to, whether or not you agree.
This is particularly fascinating. Apparently research has shown that about 70% of cases concerning obesity are directly linked to genetics and 40% of cases of alcoholism.
Namely, regardless of your stance on free will (I happen to be a determinist) we definitely don't have the freedom that most of us feel that we have. We even have studies of identical twins seperated at birth which show that, despite growing up in entirely different households, they still displayed similar outcomes and personality traits.
I've had the discussion about free will with a lot of intelligent people, most of whom are smarter than I am, I think that I'm the only hard determinist among my friends. Most are compatibilists or libertarians (that has nothing to do with the political philosophy in this context). But, I just can't shake the fact that, although the compatibilists are right that you are still making choices, you still don't get to choose who you are to begin with.
So, again, how much freedom do we actually have?