Are personalities genetic or learned? Is it possible to alter yourself in any meaningful way, or is it better to learn to accept yourself? Even if you do manage to change, was the ability to do so predestined by your nature? Is there such a thing as 'free will'?
As a society (and beyond American or even Western society, as far as I can tell), we certainly seem to believe that free will exists. It is a founding concept of our laws and ideals — "all men are created equal", personal responsibility, and so on. Even though most studies show that genetics are a far better predictor of success than environment, we refuse to believe that control does not lie within each of us. This may be one of the mental blocks we erect to protect our fragile egos — self-determination is one of the basic prerequisites for happiness, and we will come up with grand delusions to convince ourselves of our 'power to choose' if it is not really there.
Imagine for a second the consequences of a purely deterministic universe — no one is responsible for their actions, be them wonderful or terrible. Murderers aren't responsible, their genetics are. Saints are only good because they were programmed to be so. It certainly seems like society would collapse if this idea were embraced.
Of course, then there are the Calvinists, who believed in predestination (the religious flavor of determinism), and yet were some of the most pious of religious zealots, attempting to show that they were destined for salvation and heaven by displaying outwardly their internal predestined salvation. So perhaps society isn't as fragile as we make it out to be, and perhaps the ideas we hold only affect the outcome by a marginal amount — is that free will, or just noise in the system