Im quite convinced that free will is an illusion, for a few reasons;
I believe everything is pre determined, not really in the way that everything was planned out before hand, but rather that nature acts with a certain necessaty, that everything that happens - ergo everything we think/do - with the nuance in this dimension (and in this reality), everything could only happen that specific way: nature always takes the way of least resistance, the easyist possibility actually becomes reality...
Also, by now already older, Italian brain research (stated by daniel c dennett in Consious explained) showed that every consious thought we have originates out of our sub consious and that such a tought is already for one second present in the consious mind without we being aware of it (personally I find this to be a bit of a problematic notion since how can one say a thought belongs to the conscious mind without being aware of it? However, this can be logically explained - see how relative logic can be and only makes sense in correlation to certain sets of (subjectively chosen) axioms - by that when signals in a certain way, part and with a certain consistancy in the brain are detected they are considered to be part of either the sub conscious or the conscious mind... This implicates that we do not in any way choose the thoughts we have, or the desires we have, or the things we find interesting and so on and it is clear that all these things determin which actions we take; without having heard about this brain research this is a notion that instinctively seemed quite obvious to me... After all, you dont choose what you like or dislike, you simply do or dont, and this goes for everything that constitutes our self we respect so much and we tend to attach great autonomy to...
Furthermore, we are all product of what is called nature/nurture dilemma, nature meaning we are pre determined by our genetic code and nurture meaning we are pre determined by our environment - imo the ppl stating they are the least influenced by others, media, music, and so on are the most brain washed, imo the only true conviction we can have is that we all are brain washed to the fullest extent and also this notion was implemented on my brain, which I consider to be a self inforcing truth, for as far we can actually speak of truths, since we ultimately can not know anything for sure (we do can deduct from the technological exploitation of science that science must show some correlation with das ding an sich - the thing itself, Im referring to Hegel here who said: das ding an sich ist ein unbekantenes, the thing itself is unknown to us - since technology applies science in creating all kinds of apparatus that actually works with the uttermost precision, which says that the science was able to exactly predict how something would operate given the laws of nature in our universe for as far as we know/understand them), the fact that we cant know anything for sure also implies, at least in some way, that we cant know ourselves and this implies that we can not control ourselves ergo not have freedom of choice: Im willing to accept that this notion might not be the most solid constructed, but some logic seems present imo...
Considering all of this, I am really comfortable stating we most likely are not responsible for ourselves, and this has consequences for such things as punishment for certain actions such as the extreme and to me seemingly horrible imprisonment, which I personally only find justified when an individual is too dangerous to let loose and even then they actually deserve a certain life quality, and furthermore I just dont believe in prison leading to anything good, on the contrary...
A good example of how little free choice we have is the experiment they did with an actor playing up to horrible pain when some subject administers him supposedly electro shocks up to, labeled as such, lethal strength shocks simply because a guy in a white lab coat instructs the subject to, this demonstrates to what ridicoulous extremes we are capable by assuming ones authority, of course this is what lead to genocides and relating to this what Hannah Arendt titled the banality of evil in her book about the Eichmann process about how the horrors of WO II were possible to get that easy constructed.
I believe this text to be a rather solid reasoning enriched with some slight however interesting sidepaths...
