What does "free will" really mean? To the point, what is supposed to be free from what? If it is causality it must be free from, then purely random chance constitutes free will. But purely random chance has no identity. Anything that defines "you" is bound by causality. So it is not possible to combine non-causality with a self identity. There are other definitions of free will that does not demand non-causality.
There are studies, such as the Libet experiment, where clocking shows that brain activity leading to an action begins before the individual says that they made the decision. This have been claimed to constitute "evidence" that free will is an illusion, but that conclusion may just be based on the debunked assumption that free will must be non-causal.
The claim that free will is an illusion is incompatible with the whole division into "voluntary" and "autonomous" functions. If free will is an illusion, then everything is autonomous and nothing is really voluntary. If nothing is voluntary, then there is no dividing line between voluntary and autonomous, and then an illusion of free will could apply to everything, even "autonomous" functions. This means that it is just logical that refraining from justifying allows control of "autonomous" functions, as shown in multiple stages of justification poisoning. See also advice of ways to stop justifying.
So what exactly is free will? There is evidence that tolerant environments are a key factor to extreme recoveries after brain damage unexplainable by established neurological and psychological theories (reference: Kurt Fischer, Christina Hinton: Mind, Brain and Education) as outlined in brain. and the reason why children so easily acquires language is because they do not fear being wrong (references: A ecological theory of language acquisition, Chico (robot)). This means that social pressure to be righteous is devastating to the possibility of functionally free will. See advice of ways to stop justifying.
This also explains why banning certain thoughts is counter-productive, as shown in the "thinking of polar bears" experiment. But extreme recoveries after brain damage is evidently possible. The whole division into "capable of responsibility" and "incapable of responsibility" effectively creates a social pressure to be incapable of responsibility by (mal)virtue of blaming. So functionally free will ceases to exist whenever it is considered key to responsibility. Blaming the individuals for this would, by (mal)virtue of being a continuation of the blaming, just be stupid. The key to functional free will and true responsibility is to stop blaming and punishing! And as shown in moderating the Gaia/Medea debate, this is necessary for the future of the world.
The counter-productivity of punishment means that the existence of punishment/vengeance is due to the fact that the punisher thinks it works (timeservers create an illusion of obedience), consider the fact that violence rates are highest in countries with severe punishment and lowest in countries with mild punishment, implying that a significant factor in the decrease of violence is that punishments have become less severe which falsifies any claims that penal law should be a protection. Any sign of inheritance of a will to punish can be explained by inheritance of acquired characteristics. Because punishment is counter-productive, there is no way natural selection could have selected for it. Indeed, it should have selected against it. The reason why natural selection failed to eliminate punishment is most likely because natural selection by mere death or sterility of whole individuals is a way too blunt means of evolution to have any chance to fine-tune complex behavior, see self-organization.
Any attempts to explain the counterproductivity of punishment by Darwinian selection for alliances clashes with the fundamental Darwinian assumption of random mutations. If mutations were truly random, then evolution of a new instinct would always have to take into account that there would always have to be a one first individual with the new instinct and its viability where no other individuals shared that new instinct. In the absence of other individuals reacting against punishment, a first individual reacting against punishment would not have survived. So whatever the reason why punishment is counterproductive is, it cannot be Darwinian. And yet there is evidence that punishment is counterproductive.
So free will can exist, but only in the absence of justification. As soon as there are social pressure to justify actions, justification takes over and free will becomes an illusion. But if there is no social pressure to justify actions, reasons spontaneously start leading to decisions instead of vice versa, and free will becomes possible. Ergo, the key to free will is to avoid quibbling about questions such as "whose fault is it?" and "can that individual be held responsible for that action?". Since the quibble itself knocks out all free will, the answer to the first question is never one or more individuals and the answer to the last question is never yes nor no. The answer to both questions is that the questions themselves are fundamentally misframed. It is wrong to say "he/she cannot help it", but it is also wrong to blame oneself or each other. Blaming is wrong not because it is cruel in itself, but because it causes making-up of plasticity-paralyzing justifications. This rejection of justification is, thus, not about demanding accountability at all. It is about helping consciousness, intelligence, plasticity and rationality. These principles actually reject all demanding of accountability precisely because demanding accountability leads to pressure to justify, and justification locks brains and makes the stupid actions repeat. See advice of ways to stop justifying and multiple stages of justification poisoning.
The importance of tolerance for behavioral change also means that it is counterproductive to blame parents for being intolerant, since that would only cause them to make up justifications for their intolerant behavior, justifications that would stop them from changing it. Any investigations of whether or not parents committed intolerance is thus absurd, counterproductive silliness. Anyone who thinks that this neuroplasticity theory blames parents for being intolerant have therefore, frankly, not understood the theory at all. See advice of ways to stop justifying.