Tag: IQ

As someone who writes for the internet, I can tell you any story about how to be more intelligent is pretty much guaranteed to attract interest. Through the privacy of our screens, our clicks reveal that a whole lot of us are quietly anxious about our IQ scores. 

It’s natural enough to worry about whether you have the intellectual horsepower to achieve your dreams. But a new study suggests the premise behind all our anxious googling is flawed. It concluded you have a lot more influence over your IQ than you might imagine. 

How much is your IQ inborn? 

Check out the Wikipedia page for ‘IQ’ and you’ll learn that, “Psychometricians generally regard IQ tests as having high statistical reliability. Reliability represents the measurement consistency of a test. A reliable test produces similar scores upon repetition.” 

Sure, you could be hungry, tired, feeling unmotivated on a particular occasion. Or you could suffer some injury or other health setback. You can even learn hacks and habits that can tune up your effective IQ. But in general, if you take an IQ test one day and then another a month or even several years later, the scores are likely to be about the same. Intelligence, as most of us understand it, is largely fixed from birth. 

Based on this, if you look to identical twins — who by definition have the same DNA — you would expect them to have very similar IQs. And that’s historically what scientists have found. 

“Studies of identical twins, such as the landmark Minnesota Study of Twins Reared Apart, led by Thomas Bouchard, showed correlations of around 0.75 in IQ between twins separated at birth. That’s roughly the same heritability as height, which often ranges in the 0.80s,” reports Harvard researcher T. Alexander Puutio in Psychology Today. 

But a new study conducted by Jared Horvath of the English Schools Foundation Center for Research and Katie Fabricant of the University of Wisconsin that was recently published in Acta Psychologica puts a fascinating new twist on this long established finding. 

A study of twins complicates our picture of intelligence

Like many researchers before them interested in the nature vs. nurture debate, Horvath and Fabricant focused on identical twins. Their ‘nature’ is identical, which allows scientists to isolate out the effects of ‘nurture.’ Horvath and Fabricant examined one aspect of nature in particular — education. 

Looking through past studies they identified 87 pairs of identical twins that were raised separately and for whom researchers had good quality data on the type of education they received. When a pair of twins followed a similar educational path, going to schools of similar type and quality, as expected their IQs ended up very similar. But when they pursued different educational paths, the picture looked much different. 

“The results were startling, with twins that had the largest gap in years of education differing by as much as 15 IQ points,” writes Puutio. “That’s a full standard deviation’s worth of a difference, enough to shift someone from the average range into the gifted category. For the first time, we have twin-based evidence suggesting that education does more than polish existing ability; it adds new horsepower.” 

Why this matters for entrepreneurs 

This is only one relatively small study, of course. But according to University of Virginia psychologist Eric Turkheimer, it’s one in a growing body of research indicating IQ is less fixed by genes than scientists once thought. 

“In fact, the more researchers have learned about associations between DNA and IQ, the more complex and less deterministic this relationship looks,” he wrote recently in The Atlantic. 

Genes still matter for smarts but they seem to matter a lot less than we once thought they did. That’s good news for educators. But it’s also good news for any entrepreneur hoping to boost their intelligence through lifelong learning and clever cognitive strategies. (Experts have suggested trying many varieties.) 

As Puutio puts it, “If schooling can boost IQ even when genes are identical, then intelligence may be more dynamic, and more democratic, than previously thought… The line between ‘raw’ and ‘effective’ intelligence is blurring, and perhaps what we’ve called ‘innate ability’ is better understood as potential, one that education can still unlock well into adulthood.”

Bottom line: you’re less stuck with the brain you were born with then you probably imagine. It is looking more and more possible to improve your IQ through education and effort.