Generalizing From One Example

Related to: The Psychological Unity of Humankind, Instrumental vs. Epistemic: A Bardic Perspective

Everyone generalizes from one example. At least, I do.”

-- Vlad Taltos (Issola, Steven Brust)

My old professor, David Berman, liked to talk about what he called the “typical mind fallacy”, which he illustrated through the following example:

There was a debate, in the late 1800s, about whether “imagination” was simply a turn of phrase or a real phenomenon. That is, can people actually create images in their minds which they see vividly, or do they simply say “I saw it in my mind” as a metaphor for considering what it looked like?

Upon hearing this, my response was “How the stars was this actually a real debate? Of course we have mental imagery. Anyone who doesn’t think we have mental imagery is either such a fanatical Behaviorist that she doubts the evidence of her own senses, or simply insane.” Unfortunately, the professor was able to parade a long list of famous people who denied mental imagery, including some leading scientists of the era. And this was all before Behaviorism even existed.

The debate was resolved by Francis Galton, a fascinating man who among other achievements invented eugenics, the “wisdom of crowds”, and standard deviation. Galton gave people some very detailed surveys, and found that some people did have mental imagery and others didn’t. The ones who did had simply assumed everyone did, and the ones who didn’t had simply assumed everyone didn’t, to the point of coming up with absurd justifications for why they were lying or misunderstanding the question. There was a wide spectrum of imaging ability, from about five percent of people with perfect eidetic imagery1 to three percent of people completely unable to form mental images2.

Dr. Berman dubbed this the Typical Mind Fallacy: the human tendency to believe that one’s own mental structure can be generalized to apply to everyone else’s.

He kind of took this idea and ran with it. He interpreted certain passages in George Berkeley’s biography to mean that Berkeley was an eidetic imager, and that this was why the idea of the universe as sense-perception held such interest to him. He also suggested that experience of consciousness and qualia were as variable as imaging, and that philosophers who deny their existence (Ryle? Dennett? Behaviorists?) were simply people whose mind lacked the ability to easily experience qualia. In general, he believed philosophy of mind was littered with examples of philosophers taking their own mental experiences and building theories on them, and other philosophers with different mental experiences critiquing them and wondering why they disagreed.

The formal typical mind fallacy is about serious matters of mental structure. But I’ve also run into something similar with something more like the psyche than the mind: a tendency to generalize from our personalities and behaviors.

For example, I’m about as introverted a person as you’re ever likely to meet—anyone more introverted than I am doesn’t communicate with anyone. All through elementary and middle school, I suspected that the other children were out to get me. They kept on grabbing me when I was busy with something and trying to drag me off to do some rough activity with them and their friends. When I protested, they counter-protested and told me I really needed to stop whatever I was doing and come join them. I figured they were bullies who were trying to annoy me, and found ways to hide from them and scare them off.

Eventually I realized that it was a double misunderstanding. They figured I must be like them, and the only thing keeping me from playing their fun games was that I was too shy. I figured they must be like me, and that the only reason they would interrupt a person who was obviously busy reading was that they wanted to annoy him.

Likewise: I can’t deal with noise. If someone’s being loud, I can’t sleep, I can’t study, I can’t concentrate, I can’t do anything except bang my head against the wall and hope they stop. I once had a noisy housemate. Whenever I asked her to keep it down, she told me I was being oversensitive and should just mellow out. I can’t claim total victory here, because she was very neat and kept yelling at me for leaving things out of place, and I told her she needed to just mellow out and you couldn’t even tell that there was dust on that dresser anyway. It didn’t occur to me then that neatness to her might be as necessary and uncompromisable as quiet was to me, and that this was an actual feature of how our minds processed information rather than just some weird quirk on her part.

“Just some weird quirk on her part” and “just being oversensitive” are representative of the problem with the typical psyche fallacy, which is that it’s invisible. We tend to neglect the role of differently-built minds in disagreements, and attribute the problems to the other side being deliberately perverse or confused. I happen to know that loud noise seriously pains and debilitates me, but when I say this to other people they think I’m just expressing some weird personal preference for quiet. Think about all those poor non-imagers who thought everyone else was just taking a metaphor about seeing mental images way too far and refusing to give it up.

And the reason I’m posting this here is because it’s rationality that helps us deal with these problems.

There’s some evidence that the usual method of interacting with people involves something sorta like emulating them within our own brain. We think about how we would react, adjust for the other person’s differences, and then assume the other person would react that way. This method of interaction is very tempting, and it always feels like it ought to work.

But when statistics tell you that the method that would work on you doesn’t work on anyone else, then continuing to follow that gut feeling is a Typical Psyche Fallacy. You’ve got to be a good rationalist, reject your gut feeling, and follow the data.

I only really discovered this in my last job as a school teacher. There’s a lot of data on teaching methods that students enjoy and learn from. I had some of these methods...inflicted...on me during my school days, and I had no intention of abusing my own students in the same way. And when I tried the sorts of really creative stuff I would have loved as a fell completely flat. What ended up working? Something pretty close to the teaching methods I’d hated as a kid. Oh. Well. Now I know why people use them so much. And here I’d gone through life thinking my teachers were just inexplicably bad at what they did, never figuring out that I was just the odd outlier who couldn’t be reached by this sort of stuff.

The other reason I’m posting this here is because I think it relates to some of the discussions of seduction that are going on in MBlume’s Bardic thread. There are a lot of not-particularly-complimentary things about women that many men tend to believe. Some guys say that women will never have romantic relationships with their actually-decent-people male friends because they prefer alpha-male jerks who treat them poorly. Other guys say women want to be lied to and tricked. I could go on, but I think most of them are covered in that thread anyway.

The response I hear from most of the women I know is that this is complete balderdash and women aren’t like that at all. So what’s going on?

Well, I’m afraid I kind of trust the seduction people. They’ve put a lot of work into their “art” and at least according to their self-report are pretty successful. And unhappy romantically frustrated nice guys everywhere can’t be completely wrong.

My theory is that the women in this case are committing a Typical Psyche Fallacy. The women I ask about this are not even remotely close to being a representative sample of all women. They’re the kind of women whom a shy and somewhat geeky guy knows and talks about psychology with. Likewise, the type of women who publish strong opinions about this on the Internet aren’t close to a representative sample. They’re well-educated women who have strong opinions about gender issues and post about them on blogs.

And lest I sound chauvinistic, the same is certainly true of men. I hear a lot of bad things said about men (especially with reference to what they want romantically) that I wouldn’t dream of applying to myself, my close friends, or to any man I know. But they’re so common and so well-supported that I have excellent reason to believe they’re true.

This post has gradually been getting less rigorous and less connected to the formal Typical Mind Fallacy. First I changed it to a Typical Psyche Fallacy so I could talk about things that were more psychological and social than mental. And now it’s expanding to cover the related fallacy of believing your own social circle is at least a little representative of society at large, which it very rarely is3.

It was originally titled “The Typical Mind Fallacy”, but I’m taking a hint fromt the quote and changing it to “Generalizing From One Example”, because that seems to be the link between all of these errors. We only have direct first-person knowledge one one mind, one psyche, and one social circle, and we find it tempting to treat it as typical even in the face of contrary evidence.

This, I think, is especially important for the sort of people who enjoy Less Wrong, who as far as I can tell are with few exceptions the sort of people who are extreme outliers on every psychometric test ever invented.


1. Eidetic imagery, vaguely related to the idea of a “photographic memory”, is the ability to visualize something and have it be exactly as clear, vivid and obvious as actually seeing it. My professor’s example (which Michael Howard somehow remembers even though I only mentioned it once a few years ago) is that although many people can imagine a picture of a tiger, only an eidetic imager would be able to count the number of stripes.

2. According to Galton, people incapable of forming images were overrepresented in math and science. I’ve since heard that this idea has been challenged, but I can’t access the study.

3. The example that really drove this home to me: what percent of high school students do you think cheat on tests? What percent have shoplifted? Someone did a survey on this recently and found that the answer was nobhg gjb guveqf unir purngrq naq nobhg bar guveq unir fubcyvsgrq (rot13ed so you have to actually take a guess first). This shocked me and everyone I knew, because we didn’t cheat or steal during high school and we didn’t know anyone who did. I spent an afternoon trying to find some proof that the study was wrong or unrepresentative and coming up with nothing.