Richard Haier: IQ Tests, Human Intelligence, and Group Differences | Lex Fridman Podcast #302

Let me ask you to this question. Whether there's bell curve or any research on race differences, can that be used to increase the amount of racism in the world? Can that be used to increase the amount of hate in the world?

My sense is there is such enormous reservoirs of hate and racism that have nothing to do with scientific knowledge of the data that speak against that. That, no, I- I don't, I don't want to give racist groups a veto power over what scientists study.

The following is a conversation with Richard Haier on the science of human intelligence. This is a highly controversial topic, but a critically important one for understanding the human mind. I hope you will join me in not shying away from difficult topics like this, and instead, let us try to navigate it with empathy, rigor, and grace. If you're watching this on video now, I should mention that I'm recording this introduction in an undisclosed location somewhere in the world. I'm safe and happy, and life is beautiful. This is the Lex Fridman Podcast. To support it, please check out our sponsors in the description. And now, dear friends, here's Richard Haier. What are the measures of human intelligence and how do we measure it?

Everybody has an idea of what they mean by intelligence. In the, in the vernacular, what I mean by intelligence is just being smart. How well you reason, how well you figure things out. What you do when you don't know what to do. Those are just kind of everyday common sense definitions of how people use the word intelligence. If you want to do research on intelligence, measuring something that you can study scientifically is a little trickier. And what almost all researchers who study intelligence use is the concept called the G factor, general intelligence. And that is what is common, that is a mental ability that is common to virtually all tests of mental abilities.

What's the origin of, of the term G factor, by the way? It's such a funny word for such a fundamental human thing.

The general factor, it really started with, uh, Charles Spearman. Uh, and he noticed, this is like, uh, boy, more than 100 years ago. Uh, he noticed that when you tested people with different tests, all the tests were correlated positively. And so he, he was looking at student exams and things. And he invented the correlation coefficient essentially. And he, when he used it to look at student performance on various topics, he found they, all the scores were correlated with each other, and they were all positive correlations. So he inferred from this that there must be some common factor that was irrespective of the content of the test.

And positive correlation means if you do well on, on the first test, you're likely to do well on the second test. And presumably that holds for tests across even disciplines. So not within subject, but across subjects, so that's where the general comes in. Some- so- something about general intelligence. So when you were talking about measuring intelligence and, and trying to figure out something difficult about this world and how to solve the puzzles of this world, that means generally speaking. Not some specific test, but across all tests.