The Strangest Things that Correlate with IQ
When you think about IQ, you might think about scientists like Einstein or about nerds who’d rather read an academic paper than talk to another human being. But, I’m going to tell you about some of the strangest things that have been found to correlate with IQ, including in our own giant IQ study involving over 3,000 people and in the work of other researchers. So, what is IQ? Well, it’s a standardized score that’s designed to test cognitive ability, essentially what
Intelligence tasks measured in a lab have in common. So, if you give people a wide range of intelligence tasks, let’s say logic puzzles, math, spelling, vocabulary, and then you calculate a score that best predicts your performance at all of these different tasks, that’s a measure of IQ. It doesn’t necessarily predict how good you are socially or morally or whether you’re good at the sort of things that hunter-gatherers tended to be good at. Now, as we all know, a formless void
Serves the mechanics of destiny and interdependence is an unparalleled element of all experience. But, what I just said is total pseudo-profound And fascinatingly, in our study, when we gave people statements like these and asked them to rate how profound they are, higher-IQ people tend to rate them as less profound. In other words, they seem to better at calling out Perhaps this is because people with higher IQs are less likely to assume that just because they don’t
Understand something that’s actually meaningful. If you watch intellectuals on podcasts, you’ll actually see this quite a bit. They’ll say something that sounds profound but doesn’t really have any meaning, and the audience, not understanding it, assumes that it must be really deep and gives them the benefit of the doubt. When you hear things like this, I recommend deep diving and saying, “Well, what does this mean, really?” As the second child born in my family, I find this next one especially
Interesting. IQ is actually associated with being the firstborn child. It’s debated why this is, but one theory is that it has to do with parental investment. If you only have one child, you can devote more time to raising them. And Time use surveys suggest that this might actually be the case, that parents put more time into raising their firstborn child. So, perhaps this extra parental investment leads a child to have higher IQ over time. We’re not
Talking about a huge difference here. We’re just talking about a few IQ points, but it’s interesting that there’s a difference at all. Next, I want to tell you about one of the funniest correlations we found in our giant study of IQ. Who do you think has higher IQs on average? People who believe they can figure out solutions to societal problems, or people who believe they can’t figure out solutions to societal problems? Well, it turns out in
Our study, people who believe they can’t figure out solutions to societal problems actually tended to have higher IQs. Perhaps because they were more aware of how incredibly difficult it is to figure out those kinds of solutions. You might think that the explanation for this is the Dunning-Kruger effect. People sometimes mistakenly think that the Dunning-Kruger effect is that lower-skilled people think that they’re better than higher-skilled people, but that’s actually not what it is. The Dunning-Kruger effect says that
Lower-skilled people tend to overestimate their ability, not that they tend to think their ability is higher than higher-skilled people. So, this is different than the Dunning-Kruger effect. There’s a stereotype that nerdy people are more intelligent and more likely to wear glasses. And many people believe that wearing glasses gives you an air of being intelligent. Fascinatingly though, when a study tested this idea by showing faces of people either with glasses or without, people did not perceive them as
Being more intelligent when they had glasses. But, perhaps surprisingly, there actually is a link between IQ and nearsightedness. In other words, people who wear glasses probably are a little bit higher IQ on average. Why on earth would there be a link between IQ and nearsightedness though? Well, there’s a couple different theories. One theory is that nearsightedness is actually linked to the amount of light exposure you get when you’re young. So, if higher IQ children are more likely to stay indoors
Rather than spending outdoor time playing, this could actually possibly explain why they tend to be more nearsighted. Another theory is that nearsightedness is linked to close-up work, such as reading or studying. If that’s the case, that could also help explain why higher IQ children tend to be more nearsighted. So far, the correlations we’ve talked about might be interesting, but they’re not useful. So, are there useful IQ correlations that can help us guide how to live our lives? Well, there are
Actual useful IQ links that can guide our choices. One is toxins, such as lead poisoning, especially in children, which have been linked to lower IQs. Two sleep apnea. If you wake up not feeling rested and you snore really loudly, you may want to get checked out by a doctor because sleep apnea is actually treatable. Three is high blood pressure, especially as an older adult, high blood pressure is linked to a reduction in IQ over time. The fourth, perhaps most
Surprisingly, is adult hearing loss. When older adults lose their hearing, it tends to precede reductions in IQ. We don’t know for sure that it’s causal, but I think it’s worth being aware of and treating your hearing loss is good for other reasons as well. There’s also the other category, which are positive choices that are linked to higher IQ. That includes getting proper nutrition, especially as a child. It also includes boring but incredibly important things like having a healthy
Diet and exercising regularly. As a caveat here, we can’t always be certain about the causal role that these things play. For instance, it’s known that worse childhood nutrition is linked to lower IQ, but that could be because of other factors, like maybe childhood poverty is linked both to worse nutrition and to lower IQ. All of that being said, I think for a number of these, we have pretty good reason to think that there is a causal role,
Especially things like head trauma and high blood pressure. However, the most important thing to know about cognitive ability, in my opinion, is that you can get better at absolutely any task you choose simply by practicing it and getting good feedback. You don’t need to improve your IQ in order to get better at anything you care about. Someone who’s diligently studying math for 10 years is absolutely going to blow out of the water at math someone who has 10 IQ
Points higher who hasn’t studied math at all. What about beliefs? Are there any interesting correlations between IQ and what people believe? Well, fascinatingly, higher IQ people tend to be less religious. It’s not known why this is. There’s different theories. Most people in the world are born into a religion, and most people stay with whatever religion they’re born into. So, it’s possible that what’s going on here is that higher IQ people are simply more likely to question whatever belief
System they’re born into. It’s also interesting that higher IQ people tend to be more likely to support the free speech of people they disagree with. Even if they oppose what a group stands for, whether it’s Christian fundamentalists or neo-Nazis, they’re more likely to express support for that group being able to express their opinions, hold public demonstrations, and be involved in public debates. What about things that you’d expect to be correlated with IQ, but actually aren’t? Well, one of the strangest is
That you’d think that people with higher IQs would tend to be happier, because they tend to be wealthier, they tend to be better at getting certain types of jobs, and in theory, they should be able to problem-solve better in their lives. But, in fact, there is no link between IQ and life satisfaction or happiness. This is a genuine mystery that nobody has really resolved. If IQ is about being able to use your mind to effectively achieve goals, then why does
It fail at getting people the thing that almost everyone wants? But, this shows very clearly that IQ is very far from giving you everything you want in life. It doesn’t even give you happiness. A lot of people also expect that IQ is linked to conscientiousness or diligence or hard work or being organized. But, actually, studies tend to find that it has either no correlation or a very small negative correlation. It might be the case that people who are more
Conscientious tend to seem smarter. Maybe they’re more diligent about studying, maybe they have more knowledge, maybe they’re more likely to stay in school, but they don’t actually have higher IQs. Those that say IQ is meaningless are actually just scientifically wrong. It predicts lots of interesting things. But IQ is also very far from everything that matters. It can’t even predict how happy you are. If you’re interested in using psychology to improve your life, I’d love it if you
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