Transcription
We found a video of you where someone asked you about IQ and you said you were previously tested quite a while ago and you said it was in excess of 150. Granted, it does decline as you age. And you also said having a high IQ like that means that you have high volatility or variance in other areas of intelligence. As intelligence increases, the variability and intelligence increases. So psychometrically, there's sort of one way to be not very bright and a variety of ways to be very bright. So there's differentiation at the upper end, right?
And so my, I would say I'm not particularly gifted mathematically. So I struggled with statistics. I eventually figured it out, but it certainly didn't come to me easily. I don't tend to think mathematically. I've certainly had students who were like immeasurably more intelligent than me on the mathematical front. I had a student at Harvard, she went from zero statistics to winning teaching awards for teaching it in about six months. She was a little autistic. She was also a very good writer. That's a rare combination to have that extreme spatial mathematical intelligence and extreme verbal intelligence. You get a person like that now and then, it's pretty rare. And she was just coded that way to be able to do that. That wasn't anything that she did to be able to learn quickly. IQ is very biologically determined, very. And it's very, uh, it's very rough.
It's no wonder my student and I, Daniel Higgins, who was a partner in a mining business, still, we, uh, at Harvard in the 1990s, we did a lot of work investigating the world of psychometric measurement. So that would be the assessment of cognitive ability and personality. And we delved very deeply into the literature on neuropsychological function. And so that would be, that's from a field that basically derived its information from animal experimental studies as well as human beings, study of human beings with various forms of brain damage. There was a, a net effort, I don't know if that's still ongoing, to develop tests that would be associated where people would show decrements that were associated with known areas of brain damage. They developed a lot of specialized tests.
My student and I, on my old supervisor, we computerized a battery of so-called neuropsychological tests. And then we used them and IQ tests and personality to predict academic performance and managerial performance and, uh, like line worker performance. Trying to figure out, well, two things: what exactly is it that makes someone productive depending on their positioning? And then also, how could that be measured effectively? So that if you wanted to hire or place or promote, you could do that in the most effective possible manner. And so that meant that we had to thoroughly familiarize ourselves with the neurosc ological literature, which I already kind of knew, with the IQ literature, which was quite new to me, and then with the personality literature.
And so the basic claim of the psychometricians on the IQ side is that all, for all intents and purposes, IQ is relatively unitary. So intelligence, general cognitive ability, personality is multi-dimensional. But cognitive ability, although it differentiates at the upper end, is a pretty solid unit. And so, and no one likes that idea. And no wonder. It's no wonder. So why would people not like it? Well, it seems very unfair and anti-egalitarian to note that there's wide variation in the trait that is the best predictor of long-term success in complex occupations. It's not like the cards are dealt out equally. They're not dealt out equally.
How much of that is genetic? Most of it. So if you have smart parents, you're probably going to be smart. You're going to be slightly less smart than the average of your parents because imagine that your intelligence isn't determined only by your parents. It's determined in a way by the whole stream of your ancestry. Now, if you have two smart parents, on average, their ancestors are going to be slightly less smart than they are. So you get the best way to predict your IQ, if we didn't know anything else, would be to take the IQ of your mother and father and average them and then reduce it somewhat because that's called regression towards the mean. So there's a tendency for biological forms to default back to their standard configuration or increase it if the average was lower than, yeah, that's right. So if you had two parents who were impaired in their cognitive ability or far below average, on average, you'd be smarter than they were.
Would that then suggest that with enough time, we're all going to be about even? If everyone kind of averages IQ, the average is 100. MH. So hasn't it been going up over time though? There's debate about that. Um, it's gone up over time in some ways for sure. So although it's difficult to increase IQ, you, you get companies now and then who pop up and claim that they can increase your cognitive function. There's zero evidence for that. There's no. What happens if you, if you practice a complex task? You tend to get much better at the complex task, say a video game, but it doesn't transfer over and make you generally smarter. No one's figured out how to increase IQ with, with cognitive exercises. You can maintain or increase your IQ with exercise, cardiovascular and and weight lifting because your brain is a very demanding organ. So if you're cardiovascular system is healthy, especially as you age, that's a huge deal. There's nothing that you can do that's more important than staying in physical shape to maintain your cognitive ability. So, but, um, nobody knows how to increase it. I mean, that would be a, a discovery of infinite value, but no one's figured it out.
You can suppress IQ quite easily, um, by say, not stimulating young children to the degree that their intelligence has room to play, let's say, or by not breastfeeding them. That, that's a good way to have stupider children if that's what you're after. Breastfeeding confers, I think, something like a three to four point increment one year breastfed. It's something like. Why is that? Is it just the nutrition? The brain's a very demanding organ and so it uses a tremendous am of your metabolic resources. And so nutrition and exercise make a huge difference. Um, so if you take, you asked about biological determinism with regards to IQ. So imagine that you take twins, identical twins who were separated at birth and then you track their IQ as they age. Well, by the time they're 60, their IQs are so similar regardless of their background that it's as if you're testing the same person twice. So strangely enough, if, if IQ is environmentally determined, you'd expect twins separated at birth to diverge as they age. They don't. They converge.
So I can see that why that, uh, makes people very upset. There's a whole bunch of reasons to be upset by it. I mean, the, when, when Daniel and I sorted this out in the 90s, we thought that this might be the sh upon which Western culture demolishes itself because IQ is a vicious predictor of long-term success. It's by far the, the best predictor. It's five times as powerful as conscientiousness, which is the next best predictor. So conscientiousness is associated with industriousness and orderliness. It's associated with political conservatism. It's associated with traditionalism, outgroup, let's say skepticism towards outg groups to some degree. That's conservatism more. But, um, and we probably can't measure conscientiousness as accurately as we can measure IQ. We have to rely on personality scale and self, self-report and reports from other people. That's the best we've been able to manage.
And no one has been able to come up with a practical test of conscientiousness. Like I'm probably trying 50 things in my lab, bringing conscientious people into the lab, giving them different sorts of tests, seeing if we could figure out what activity conscientious people would do better in the lab so we could use that as a measure. We could never do it. We did things like, for example, imagine you have rows of N's, M's, U's, which are visually quite difficult to distinguish. Imagine a variety of rows of those, and then your job is to go through and circle all the N's. You'd think perhaps that would be associated with something like diligence or industriousness, conscientiousness, but it's just another IQ test. It's very, very hard to find a cognitive test that isn't just IQ. And IQ is very easy to measure.
This is another thing that makes it troublesome, let's say, apart from the fact of unbelievable variation between people. Like people with extreme I Qs are so much more productive than people with on the lower end of the scale that they're not in the same universe in a sense. And they're certainly in the same moral universe and they have the same value intrinsically. And, and IQ is not associated with morality, let's say. Just because you're smarter doesn't mean you're a better person. And in fact, I think there's a temptation that comes along with intelligence that's luciferian. And that's been warned about in mythologies for ever. Bitter intellect, you know, the person who has been gifted by God, so to speak, with a great intellect, who believes that the world should bow at their feet in consequence or presumes that their rational, what would you say, their cogitations produce systems of value that should be imposed upon the world. That's the luciferian temptation.
But there's a massive difference between people at the upper end of the ctive distribution and people at the lower end. And, and, and it's easy to measure. It's very robust. So, for example, imagine you had a, a library of 10,000 questions, questions about anything, they they require abstract cognition to solve. That's the only criteria. Multiple choice questions, vocabulary questions, general knowledge questions, mathematical questions, spatial rotation questions, anything that requires abstract cognition. Okay. So you have 10,000 questions. Extract out a random set of 100 questions, give that to 100 people, sum their scores, rank order them. That's IQ. Now, the technical IQ test correct for age, but you know, that's irrelevant with regards to the measurement.