I have been wondering about what we can learn from the addiction literature about free will. I'd like to hear people's thoughts on this. I am not an expert on the philosophy of drugs (i am experimental social psychologist with expertise in self-regulation and a smattering of other stuff), and i am just going in and reading the literature to see what i can see. I try to have no preferences other than to figure out what's up, and simply to follow the data.
It seems there are two very different positions. One is that addicts lose free will, though only specifically with respect to the addiction, and they retain free will (and moral responsibility) in most or all other respects. The other position is that there is no loss of free will and that maintaining addiction is voluntary behavior.
It looks like addicts themselves and the medical establishment firmly favor the no-free-will position. But then it is self-serving for them, and they do not mostly have large impartial data sets. In contrast, the researchers, who do have these broad data sets, are somewhat more divided, with perhaps more leaning toward the free will side.
Addiction seems somewhat like a really bad itch that you know you shouldn't scratch. You can't help wanting to scratch, though ultimately you do have free will and retain control over whether you scratch or not. The problem is, an occasional scratch won't really matter, but the few lead to the many, and many scratchings are very bad for you. As George Ainslie says, willpower resides in treating each act as an examplar of what you should always do.
A variety of evidence supports the free will position. First off, most addicts do quit. Many quit and then relapse, but many others quit and do not relapse. This empirical pattern was not found and then not appreciated for a long time, especially by the medical establishment, because addicts in professional treatment samples mostly do not quit and then mostly relapse. What's more, those clinical samples of addicts mostly have multiple psychological problems. All these things are different in nonclinical addict samples, the majority. The thing is, most research studies use the more convenient samples, namely the addicts in treatment, not realizing that they aren't typical. So the literature gets this distorted impression of addicts as deeply pathological, hopeless cases, who either cannot quit or will soon relapse.
This is the sort of error psychology has made repeatedly. A famous previous example was with homosexuality. Theories of homosexuality first emerged from clinicians who treated many homosexuals, and they observed that homosexuals were neurotic and so forth. Homosexuality itself was long considered one form of mental illness. But eventually it became clear that most homosexuals, especially those not currently going to psychotherapy, were not neurotic, and homosexuality itself is not a mental illness.
The mistake with homosexuality got corrected in part because many gay people came forward to insist that the prevailing views were wrong. Their voices were heard. Unfortunately for the cause of truth, no addicts are standing up to insist that addicts are mostly sane, capable, responsible individuals, or otherwise undeserving of being regarded as mentally ill. Au contraire, many addicts benefit from being diagnosed as mentally ill, and especially as unfree. When celebrities or public figures are disgraced because of misbehavior from drugs or addiction or whatever, they prefer to come forward and say that this was the addiction talking and acting, it robbed me of free will. It is an illness, like diabetes, and I cannot be blamed it or for its effects on me.
Even with heroin, apparently, the most common pattern is to become addicted in one's early twenties and to stop using heroin pretty much for good in one's late twenties. Stanton Peele said "People who have better things to do don't become addicted." This struck me as outrageous when I first read it, but I must say that most of the evidence I have seen is consistent with it. Most heroin addicts approaching thirty realize that if they want to pursue some particular chance of a career or family, they need to stop spending all their time zoned out, and they manage it, withdrawal and all. Addiction starts and more-or-less normal adult life starts.
Likewise, cigarette smokers have quit in large numbers. Back in 1960, when the bad news about smoking began to come out in the mass media, most American men were smokers. Today less than a quarter are. Moreover, many of them have quit multiple times, which shows they can quit.
There seem to be differences of opinion about the physical dimension of addiction. Some say there is no way to tell the difference between a corpse of an addicted alcoholic and a corpse of somebody who drank the same amount without being addicted (even, for ex., somebody imprisoned and forced to drink). Others point to withdrawal symptoms and other things indicative of some physical dependency. Even so, does physical dependency entail loss of control? Or is it just like a really tempting itch?
With smoking, it seems, lots of people quit. At first it is very unpleasant, with many negative symptoms. After about a month, all but two of the symptoms are mostly gone. The remaining two are increased food appetite and weight gain. The most likely explanation is that nicotine suppresses appetite and thereby keeps weight down, and these go back to baseline when one quits, so they are not symptoms of withdrawal but simply the normal bodily condition that was artificially suppressed during the smoking addiction.