A few years ago, I read an awesome book called The Theatre of the Mind by Jay Ingram. It's a science book, summarising and explaning research for lay readers, about how the human mind functions, and the gist is this:
Most of the time, the choices we think we make have already been made in the subconscious mind before we even are aware that there's a decision to be made, based on innumerable pre-existing factors of which, again, we're often not even aware. The brain then tricks us into thinking we're actually making decisions rationally.
In other words, "free will," at least the way most people think of it, is an illusion. Quite frequently, even in situations where we think we can choose to behave in one way or another, we're actually only capable of choosing one way. All manner of things control our choices: our childhood experiences, the language(s) we speak, class, race, gender, sexuality, religious beliefs, diet, sleep patterns, weather, time of day... And all of that happens before our conscious mind even realises there's a choice to be made, so it "makes" the decision the subconscious brain has already approved.
I find it kind of liberating not to believe in free will. It's not the same as abdicating responsibility by claiming that some deity has predestined everything so we're off the hook. Rather, it's a recognition that I behave in certain ways for certain reasons and that's my personality, and I can't simply choose to behave in completely contrary ways any more than I can simply choose to be Angelina Jolie.
