Folks who work in the field of neurobiology think so (mind you i'm just playing the devil's advocate here to get people thinking).
"A person's conscious thoughts, intentions, and efforts at every moment are preceded by causes of which he is unaware. What is more, they are preceded by deep causes — genes, childhood experience, etc..." - Sam Harris
To that last statement, doesn't it kinda confirm the skepticism i'm putting out? You can't say if you don't know, and if you don't know, what is most likely the case?