Even if Lots of Mental Illnesses Are Just Preferences, Caplan Is Still Wrong About Mental Illness

Parfit vs Szasz

I wasn’t going to weigh in on the long-standing dispute between Scott Alexander and Bryan Caplan about mental illness. I basically think that, while Caplan is great, Scott Alexander is right about everything in the dispute and Caplan is wrong about everything. I also realized writing the post would require repeatedly typing Thomas Szasz’s name, and I have a strong preference for not doing that, so I decided not to weigh in.

But suppose that this preference to not type Szasz’s name dramatically hampered my quality of life. Because of my refusal to type Szasz name, my friends deserted me, future spouses left me, and people threw eggs at my house. Suppose god rewarded, rather than those who are virtuous, those who are willing to type the name of he-who-must-not-be-named. Suppose I knew this. In this case, my irrational aversion to typing out Szasz’s name would seem like a mental illness.

Caplan’s position in the long-standing dispute is that if something is responsive to incentives, it can’t be a mental illness. So if one had Down syndrome, that would be a legitimate illness, because they can’t do anything about that—you could pay them 1 billion dollars to revert back to a normal head shape, number of chromosomes, and to have a higher IQ and they wouldn’t do it because they can’t. In contrast, alcoholism is just an idiosyncratic preference—if you threatened to torture a person for all of eternity if they drank again, they’d probably never drink.

But think back—not very far, it appeared two paragraphs ago—to the case where I have an irrational preference for not typing out Szasz’s name. Even though this is a preference and is responsive to incentives, it seems like an illness. Preferences can be bad, and if one’s preferences are irrational and bad, then this seems like a mental illness.

Lots of people cut themselves. Cutting oneself is often symptomatic of mental illness, even if the people who do it have a preference for doing it and suffer no delusions when they are doing it. The reason it’s mental illness is that it is bad to cut oneself, and if some preference is abnormal and very harmful—potentially with other qualifications—it is a mental illness.

Caplan and Szasz seem to think that their view of mental illness—according to which most of it is just weird preferences—makes the case against treating various mentally ill people. As Caplan says:

If you’re paying attention, you know that I totally disagree with Emil. And you know why. To repeat: Preferences can’t be diseases! Not alcoholism, not idleness, not the urge to commit murder, and not your sexual preferences.

Szasz says (try saying that three times fast, or worse, spelling it):

Involuntary mental hospitalization is like slavery. Refining the legal or psychiatric criteria for commitment is like prettifying the slave plantations. The problem is not how to improve or reform commitment, but how to abolish it.

But . . . why? Why can’t preferences be diseases? Caplan claims that these are just unusual preferences, saying “a large fraction of what is called mental illness is nothing other than unusual preferences.” But even if they are just preferences, they are the bad kind of preferences. If you have an insatiable preference for eating a car, having sex with small children, setting yourself on fire despite that bringing you no pleasure, or torturing yourself to death, those are all preferences, but if there was a way to cure them, they’d be very worth curing and would be mental illnesses.

The philosopher Derek Parfit gave a famous example of an irrational preference with his case of future Tuesday indifference. Suppose that a person doesn’t care what happens to them on future Tuesdays. So they set up an arrangement where they’ll be brutally tortured on Tuesday for the sake of small benefits on Monday. Of course, when Tuesday rolls around, they try to get out of the torture, by agreeing to more tortures on a future Tuesday—they only are indifferent to future Tuesdays, not present ones. That seems clearly irrational. Furthermore, this case seems analogous to various mental illnesses like, for example, alcoholism. Both are preferences, but they are bad preferences, one’s that one has a reason not to have. If you endure suffering on Tuesday to give minor benefits to yourself on Monday, that is irrational. Cases like this show that preferences can be rational or irrational. But if preferences can be irrational—given that there is, of course, a mental basis for a preference—then bad preferences are harmful brain deficiencies, causing people to act irrationally. Just as delusions that one can fly that cause them to go jumping off buildings are obviously mental illnesses, so too should delusions that one’s pain on Tuesday isn’t bad that result in horrible misery be categorized as mental illnesses.

Of course, Caplan and Mr. Pzzazszspaz could reply that this definition is too expansive—if all bad preferences are mental illnesses, then liking sugary foods is a mental illness, because it’s harmful. But I haven’t given a definition. I do not have a precise checkbox, where something is a mental illness only if it meets some specific criteria. But we don’t have that for almost any word.

Take the example of the word knowledge. Philosophers have been debating what knowledge means for about a century with no signs of agreement. Edmund Gettier famously proved that the earlier accounts of knowledge were systematically wrong. And there are lots of other examples: morality, possibility, gender, magic, well-being, etc. So even though mental illness can’t be satisfactorily defined by those who disagree with Caplan, I don’t think it can be adequately defined by Caplan either. I think Caplan says that mental illness is just socially stigmatized preferences, but that’s not true—people don’t think wanting to beat one’s spouse is a mental illness, though it’s a socially stigmatized preference.

On my view, whether something is a mental illness will be a complicated judgment that combines normative considerations, how common the potential mental illness is, and lots of other things. Such a definition will be imprecise. But the fact that there isn’t a precise definition isn’t a problem.

Scott Alexander in his reply to Caplan gives a nice example of the point:

Consider Prader-Willi syndrome, caused by damage to a region of chromosome 15. Symptoms tend to include short limbs, mental retardation, and extreme hunger. Here’s how the NYT describes this last problem (content warning for body horror):

One result is a heightened, permanent sensation of hunger. “They describe it as physical pain,” Jennifer Miller, an endocrinologist at the University of Florida who treats children with Prader-­Willi, told me. “They feel like they’re going to die if they don’t get food. They’re starving.” Parents must lock their pantries, refrigerators and trash cans, and their children frequently lie and steal to get something to eat. They have been known to memorize credit-card numbers and secretly phone for delivery, use a drill to remove the door from a locked refrigerator and break into a neighbor’s garage and eat, uncooked, an entire frozen pizza.

And here’s how it describes one particular patient’s last moments:

In 2004, Peter and Gayle Girard held their annual Christmas Eve party for family members at their home in Orlando, Fla. Before dinner, they set out chips, vegetables and dip, shrimp, a bowl of punch and sodas. Their 17-year-old son, Jeremy, had Prader-­Willi, and they often hosted events at their home so he could join in while they kept an eye on him — as they believed they were doing that night. But the next morning, Jeremy’s belly was distended, and he complained of pain. At the emergency room, doctors pumped his stomach, but his condition worsened. A day passed before surgeons discovered that his stomach, which had been distended long enough to lose blood flow and become septic, had ruptured. Jeremy died that night. Only afterward did the Girards learn that other family members saw him eating more than he should have but didn’t alert them.

I insist on calling Prader-Willi syndrome a disease, and a serious one, even though the extreme hunger of Prader-Willi is continuous with/shades into the normal hunger where I would like a slice of pizza.

My preference for pizza is so easily satisfied that it rarely bothers me. It’s ego syntonic - I am fine with being the sort of person who likes pizza. It’s socially normal - everyone likes pizza. It doesn’t cause much trouble - it wouldn’t improve my life much if I stopped wanting pizza. So I think of it as a preference. If it were otherwise - the extreme hunger of someone with Prader-Willi - it would be more natural to talk about it as a compulsion, a sense of extreme pain inflicted on me when I wasn’t eating enough, something ontologically similar to a stomach flu that also produces extreme pain in the abdominal region.

This seems obviously like a preference. But it’s an abnormal, harmful preference, such that it should be subject to treatment if treating it works. As far as I can tell, Caplan gives no argument for why mere preferences can’t be illnesses. So even if we accept that the incentive test is a good test of mere preferences, this does nothing to show that things that are preferences can’t be mental illnesses.

Caplan has a reply to the claim that mere irrationality suffices to establish a mental illness. He notes that we only count things as mental illnesses when the irrationality is not widespread. Caplan quotes Szasz:

If you believe you are Jesus or that the Communists are after you (and they are not) – then your belief is likely to be regarded as a symptom of schizophrenia. But if you believe that Jesus is the Son of God or that Communism is the only scientifically and morally correct form of government – then your belief is likely to be regarded as a reflection of who you are: Christian or Communist.

I largely agree with this! But . . . so what? We can’t call all harmful or irrational beliefs or preferences mental illnesses. If we tried to subject all Christians to involuntary psychiatric treatment, we’d probably have a civil war, and that would be bad. So instead, we take the low-hanging fruit of very harmful and irrational preferences and call them illnesses if they’re the types of things that are worth being concerned about and treating if possible.

So even if mental illnesses are just preferences, Caplan would still be wrong. Crucially, Caplan’s normative conclusions wouldn’t follow, because harmful and irrational preferences are worth treating much the same way we treat harmful and irrational non-preferences. If something is harmful, irrationality inducing, worth treating, worth seeing a therapist about, and worthy of rigorous psychiatric research, then it should be treated as a mental illness. If it walks like a duck, and talks like a duck . . .