Every SINGLE one of our actions, thoughts and random brain-storms, are caused as a reaction to our surroundings, teaching, our own understanding of "self", the possible consequences, determining the outcome or possible outcomes, past experiences etc. and other such factors.
Really, OUR DECISION is actually totally influenced by surrounding input, true "free will" is therefore nonexistant.
The theory that we cannot predict human behavior is actually very false...everyone in the marketing and PR departments do so AS THEIR JOB, and not to say the social experiments carried out by scientists to study human behavior.
When presented with a given situation, we are XX% likely to act (Way A)...
Our conciousness is NOT free will...it is all determined by other factors, which are so numerous and diverse that you cannot effectively and accurately meassure it, but you can do a prediction.
I also like how there seems to be only "Free will or Pre-determination"...when there could be NEITHER (and is, in my understanding). Because it is not entirely free because it is very constrained and limited, and not pre-determined because our own life and those interacting with us forms that frame.