I see claims like this surprisingly often:

Of course there are smart people who are insane, and dumb people who are completely rational. But if we define intelligence as having something to do with accurately understanding and interpreting the information we constantly receive from the world, necessary to make accurate predictions about the future and how one’s interactions with others will go, there’s a clear correlation between accurately understanding the world and being sane.

In other words, a sufficiently dumb person, even a very sane one, will be unable to distinguish between accurate and inaccurate depictions of reality and so can easily espouse beliefs that sound, to others, completely insane.

Is there any way to distinguish between a dumb person who believes wrong things by accident and a smart person who believes wrong things because they are insane?

Digression: I have a friend who was homeless for many years. Eventually he was diagnosed as mentally ill and given a disability check.

“Why?” he asked, but received no answer. He struggled (and failed) for years to prove that he was not disabled.

Eventually he started hearing voices, was diagnosed with schizophrenia, and put on medication. Today he is not homeless, due at least in part to the positive effects of anti-psychotics.

The Last Psychiatrist has an interesting post (deleted from his blog, but re-posted elsewhere,) on how SSI is determined:

Say you’re poor and have never worked. You apply for Welfare/cash payments and state Medicaid. You are obligated to try and find work or be enrolled in a jobs program in order to receive these benefits. But who needs that? Have a doctor fill out a form saying you are Temporarily Incapacitated due to Medical Illness. Yes, just like 3rd grade. The doc will note the diagnosis, however, it doesn’t matter what your diagnosis is, it only matters that a doctor says you are Temporarily Incapacitated. So cancer and depression both get you the same benefits. Nor does it matter if he medicates you, or even believes you, so long as he signs the form and writes “depression.”(1) The doc can give you as much time off as he wants (6 months is typical) and you can return, repeatedly, to get another filled out. You can be on state medicaid and receive cash payments for up to 5 years. So as long as you show up to your psych appointments, you’ll can receive benefits with no work obligation. “That’s not how it works for me” you might say, which brings us to the whole point: it’s not for you. It is for the entire class of people we label as poor, about whom comic Greg Geraldo joked: “it’s easy to forget there’s so much poverty in the United States, because the poor people look just like black people.” Include inner city whites and hispanics, and this is how the government fights the War On Poverty. In the inner cities, the system is completely automated. Poor person rolls in to the clinic, fills out the paperwork (doc signs a stack of them at the end of the day), he sees a therapist therapist, a doctor, +/- medications, and gets his benefits. There’s no accountability, at all. I have never once been asked by the government whether the person deserved the money, the basis for my diagnosis– they don’t audit the charts, all that exists is my sig on a two page form. The system just is. Enter SSI, Supplemental Security Income. You can earn lifetime SSI benefits (about $600/mo + medical insurance) if “you” can “show” you are “Permanently Disabled” due to a “medical illness.”

“You“= your doc who fills out a packet with specific questions; and maybe a lawyer who processes the massive amounts of other paperwork, and argues your case, and charges about 20% of a year’s award. “show” has a very specific legal definition: whatever the judge feels like that day. I have been involved in thousands of these SSI cases, and to describe the system as arbitrary is to describe Blake Lively as “ordinary.” “Permanently disabled” means the illness prevents you from ever working. “But what happens when you get cured?” What is this, the future? You can’t cure bipolar. “Medical illness” means anything. The diagnosis doesn’t matter, only that “you” show how the diagnosis makes it impossible for you to work. Some diagnoses are easier than others, but none are impossible. “Unable to work” has specific meaning, and specific questions are asked: ability to concentrate, ability to complete a workweek, work around others, take criticism from supervisors, remember and execute simple/moderately difficult/complex requests and tasks, etc. Fortunately, your chances of being awarded SSI are 100%…

It’s a good post. You should read the whole thing.

TLP’s point is not that the poor are uniformly mentally ill, but that our country is using the disability system as a means of routing money to poor people in order to pacify them (and maybe make their lives better.)

I’ve been playing a bit of sleight of hand, here, subbing in “poor” and “dumb.” But they are categories that highly overlap, given that dumb people have trouble getting jobs that pay well. Despite TLP’s point, many of the extremely poor are, by the standards of the middle class and above, mentally disabled. We know because they can’t keep a job and pay their bills on time.

“Disabled” is a harsh word to some ears. Who’s to say they aren’t equally able, just in different ways?

Living under a bridge isn’t being differently-abled. It just sucks.

Normativity bias happens when you assume that everyone else is just like you. Middle and upper-middle class people tend to assume that everyone else thinks like they do, and the exceptions, like guys who think the CIA is trying to communicate with them via the fillings in their teeth, are few and far between.

As for the vast legions of America’s unfortunates, they assume that these folks are basically just like themselves. If they aren’t very bright, this only means they do their mental calculations a little slower–nothing a little hard work, grit, mindfulness, and dedication can’t make up for. The fact that anyone remains poor, then, has to be the fault of either personal failure (immorality) or outside forces like racism keeping people down.

These same people often express the notion that academia or Mensa are crawling with high-IQ weirdos who can barely tie their shoes and are incapable of socializing with normal humans, to which I always respond that furries exist.

These people need to get out more if they think a guy successfully holding down a job that took 25 years of work in the same field to obtain and that requires daily interaction with peers and students is a “weirdo.” Maybe he wears more interesting t-shirts than a middle manager at BigCorp, but you should see what the Black Hebrew Israelites wear.

I strongly suspect that what we would essentially call “mental illness” among the middle and upper classes is far more common than people realize among the lower classes.

As I’ve mentioned before, there are multiple kinds of intellectual retardation. Some people suffer physical injuries (like shaken baby syndrome or encephalitis), some have genetic defects like Down’s Syndrome, and some are simply dull people born to dull parents. Intelligence is part genetic, so just as some people are gifted with lucky smart genes, some people are visited by the stupid fairy, who only leaves dumb ones. Life isn’t fair.

Different kinds of retardation manifest differently, with different levels of overall impairment in life skills. There are whole communities where the average person tests as mentally retarded, yet people in these communities go providing for themselves, building homes, raising their children, etc. They do not do so in the same ways as we would–and there is an eternal chicken and egg debate about whether the environment they are raised in causes their scores, or their scores cause their environment–but nevertheless, they do.

All of us humans are descended from people who were significantly less intelligent than ourselves. Australopithecines were little smarter than chimps, after all. The smartest adult pygmy chimps, (bonobos) like Kanzi, only know about 3,000 words, which is about the same as a 3 or 4 year old human. (We marvel that chimps can do things a kindergartener finds trivial, like turn on the TV.) Over the past few million years, our ancestors got a lot smarter.

How do chimps think about the world? We have no particular reason to assume that they think about it in ways that substantially resemble our own. While they can make tools and immediately use them, they cannot plan for tomorrow (dolphins probably beat them at planning.) They do not make sentences of more than a few words, much less express complex ideas.

Different humans (and groups of humans) also think about the world in very different ways from each other–which is horrifyingly obvious if you’ve spent any time talking to criminals. (The same people who think nerds are weird and bad at socializing ignore the existence of criminals, despite strategically moving to neighborhoods with fewer of them.)

Even non-criminals communities have all sorts of strange practices, including cannibalism, human sacrifice, wife burning, genital mutilation, coprophagy, etc. Anthropologists (and economists) have devoted a lot of effort to trying to understand and explain these practices as logical within their particular contexts–but a different explanation is possible: that different people sometimes think in very different ways.

For example, some people think there used to be Twa Pygmies in Ireland, before that nefarious St. Patrick got there and drove out all of the snakes. (Note: Ireland did’t have snakes when Patrick arrived.)

(My apologies for this being a bit of a ramble, but I’m hoping for feedback from other people on what they’ve observed.)