Reading is the basic skill for all subjects.
If you don’t have the motivation to read,
you can’t study any other subject.
—Kari Louhivuori,
Finland’s Council for Creative Education
A teacher’s task is not to ensure
that students have read the literary canons.
It’s to kindle excitement about reading.
—Adam Grant
Recently, I was eating breakfast at a local café when the thought occurred to me that all of us at the surrounding tables were actively bouncing up and down as the earth beneath us continuously flexed. And no, the seismic activity wasn’t strong enough to be felt; I was simply struck by the insight that between the earth’s rotation and the sloshing of the tectonic plates, that the ground beneath my feet is never actually rigidly solid. We live on the equivalent of a bucking bronco operating at such slow speeds that the only time we ever do notice is during the abrupt acceleration we call an earthquake. But the quaking? It’s happening everywhere on our planet’s surface all the time.
As for what triggered this unbidden thought, I was, of course, reading—in this case about seismometers in Antarctica—and as all reading does, it generated thinking and that thinking in turn generated a new bit of knowledge (at least new for me). Indeed, so critical to human cognition are reading and its corollary, writing, that we Homo sapiens have been attempting to design and construct these formal systems for the transmission of complex thought since at least 40,000 years ago (see Mogensen). Moreover, once we did successfully invent reading and writing, civilizations arose, and when we figured out via the printing press how to make the written word available to everyone, the intellectual explosions of the Enlightenment, the Industrial Revolution, and the rest of the Modern Era became possible. Having repurposed the necessary neural circuitry, our collective intelligences blossomed in kind.
Which brings me to a very interesting—and probably highly significant—correlation between reading habits and population IQ levels. Namely, the more people read, the smarter they test on such “gold standards” of general cognitive assessment as the OECD’s international PISA test and the U.S. NAEP’s “Nation’s Report Card.” What’s more, the correlations can be quite dramatic.
For example, during most of the first decade of the 21st Century, the country with the highest PISA scores in the world was Finland and other countries rushed (legitimately but that’s another topic) to study what the Finnish educational system was getting right. But starting in 2006, this nation’s PISA scores steadily dropped for more than a decade in every domain the test assesses. Meanwhile, “compared to 2000, in 2018 the average Finnish teen was spending 77 fewer hours a year reading for fun” (Grant, p. 174). Interesting, no? Furthermore, since American reading habits were even more abysmal during this time, with “students’ enthusiasm about reading [continuing] to wane year after year” (Grant, p. 174), it should come as no surprise that the U.S. has consistently produced some of the lowest PISA scores in the world.
Yet, among 9-year-olds in this country, there is growing evidence of improving IQs (see Moyer) at the exact same time that reading scores on the most recent NAEP assessment improved significantly. Some of this, no doubt, is because more and more states have embraced using the science of reading in their elementary classrooms, but the correlation between reading habits and general cognitive ability persists—in this case, in a positive direction—and I think we ignore that at our peril.
Because while every good statistician and scientist knows that correlation does not equal causation, this is one situation where the brain’s hard-wired bias towards focusing on the negative should be used to our advantage. The assumption that reading more causes IQs to go up and that reading less causes IQs to do down is the safer evolutionary bet because should the correlation prove spurious, the worst that has happened is that people spent some additional time reading; while if the causal link eventually proves true, current dominant reading habits make us fish in the proverbial barrel for authoritarians and con artists alike.
Therefore, find ways to promote reading in your communities; model it for your children and grandchildren by reading with them and in front of them; make time for students to do it in your classrooms with books of their choosing (since the research is clear that doing so makes them more passionate about reading). And remember that “intrinsic motivation is contagious; when students talk about the books that light up their imagination, it crystallizes why they love them—and gives others the chance to catch that enthusiasm” (Grant, p. 175). So don’t just read; find ways to communicate what you are discovering with others and help the children in your lives do likewise.
Because the ultimate IQ booster is teaching what we’ve learned to others. It is called the tutor effect, and one of the most fascinating examples of it is with the firstborn in families. The oldest child consistently displays a slight cognitive edge over their younger siblings (even when the research controls for socio-economics, parental education level, family size, etc.), and even “only children—who get the most undivided attention—test as less bright than firstborns with younger siblings” (Grant, p. 134; original emphasis). Simply put, having a built-in group of “pupils” gives firstborns the necessary environment to grow their IQ just a bit more than those who come after them.
Unless, of course, those younger siblings are more avid readers. After all, to the most well-read goes the most IQ spoils.
References
Grant, A. (2023) Hidden Potential: The Science of Achieving Greater Things. New York: Penguin Books.
Mogensen, J.F. (May 2026) Ancient Lexicon. Scientific American. Pp. 14-15.
Moyer, M.W. (April 2026) The Kids Are All Right. Scientific American. Pp. 36-41.
Light a Candle 