There was an article in the NY Times last week that got me thinking. The article was about some recent research on people's understanding of free will and moral responsibility.
From my cognitive science background, I know that everything we do and think is a product of what we are perceiving from outside our brains in combination with what is currently active in our brains in a not-always-predictable interaction. But not predictable is not the same as free will.
Everything going on in our brains is a product or what we have recently perceived along with what was in our brain before that. What was in our brain before that is a function of what we were perceiving before that and what was in our brain before THAT. And so on back to birth, and to some extent to conception. That part is defined by genetics.
So in sum, what we are thinking and doing right now is a direct result of genetics plus the sum total of everything we perceived outside our brains since conception - again in some unpredictable combination/interaction. The only place that variation occurs is at the atomic level due to the Heisenberg Uncertainty Principle. Our atoms have some free will, but we don't. As Schopenhauer said (to paraphrase), we can do what we will, but what we will is predetermined.
But the article in the NYT makes some important points. Society depends on us believing that we have free will. People who doubt free will, even temporarily due to extenuating circumstances, are less honest, less ethical, do worse at their jobs, do worse in their relationships, and are more forgiving of other people's transgressions.
So even if what I argued above is true, don't tell anyone about it, don't believe it yourself, and continue along as if it were not true. At least that's what I CHOOSE to do.