Personally, I do feel inclined to believe that there is a certain measure of free will in human agency and volition. In fact, both these terms would be utterly meaningless otherwise, but this is not the reason why I have this inclination.

Another important distinction that you seem to miss is that possessing free will is not the same thing as exercising it. You can find an overwhelming number of instances of people not exercising free will and simply letting their evolutionary autopilot mechanisms to do the job for them. Breathing is a fairly simple and universal example of something people do aside from any exertion of free will; they just do it. But while this list may be huge, it certainly does not entail that we do not have the ability to exercise free will. It even might be true that women almost always touch their hair when they are interested in men (I'm not sure about this, I've never seen any study pointing to it); it might be true that we act upon instinctual impulses a lot of the time; still, for free will to be null, it had to be true also that, when people do this, there was no way they could have done anything else, and this is where there is no compelling evidence whatsoever.

I'm not arguing for the end result; actually, I've been insisting on the nature of the causal mechanisms from the first comment I posted. You argue that determinism rules every event which concerns human agency, while I argue that this is largely an unsettled question, with the complexity of available data conforming more to probabilistic models than deterministic ones. Again, I restate my case: an argument against free will based on causal determinism is not a solid argument; it is not even an original one, being around since the ancient Greek philosophers; and determinism is not even a hard fact of reality, but at most an emergent feature of the fundamental probabilistic nature of reality relevant only to a subset of systems which are very large or very stable as compared to atomic scales.

Mental processes, which are very likely to arise from the complex activity going on in neural networks, may reasonably fall either side of this dichotomy between determinism and non-determinism, owing precisely to the intermediate dimensions of the system and phenomena which serve as its physical basis. Again, until we properly understand the connection between physiology and psychology, the question of free will is an open question.