This free will speech by Steven Pinker raises some interesting points and facts about the process involved in our choices as human beings.
Steven's idea of free will does not involve an inner being that, as he describes, "pulls levers." Instead, he attributes it to complex processes in the brain. Because of the intense complexities of the brain, Steven says we can't predict the choices of humans.
Steven does say that there are certain reactions that can be predicted, such as natural reflexes like our pupils shrinking from light or our legs kicking when our knees are tapped. But these are completely different than choices such as picking what to have for dinner. The decisions are also derived from another part of the brain.