Is Intelligence Real?
A response to Daniel Willingham and Eric Turkheimer
Discussions of intelligence and IQ in the K–12 world are usually not worth the trouble. The subject is too fraught with controversy, associated with various horrors of the 20th century, and too attractive to Twitter racists.
Intelligence is also irrelevant to many discussions in K–12, so we don’t need to talk about it very often. But sometimes we do, and if we’re going to discuss intelligence and IQ, we should do so clearly and accurately.
In their new column for AFT’s American Educator magazine, Eric Turkheimer and Daniel Willingham fumble the bag badly enough that it warrants a response.
I’m well aware that I’m out of my league here. I am not a cognitive psychologist, and among cognitive psychologists, Willingham and Turkheimer are big names. I don’t expect to get everything right, and I invite the reader to correct me on any points I’ve gotten wrong.
You can leave a comment below or submit a standalone article—EdSkeptic accepts contributions.
I also have a great deal of personal respect and regard for Willingham, who has been a gracious guest on my podcast (here and here) and has written superb books that I’ve enjoyed.
That’s why this article is such a mystery. I genuinely don’t understand why it missed the mark so badly.
The “Essentialism” Straw Man
Willingham and Turkheimer’s signature move in this article is to reframe the common-sense concept of intelligence as “essentialism.”
This is a standpoint I have never heard anyone argue, and don’t think anyone holds, but it’s fairly easy to attack, so it’s a useful straw man. They say:
But IQ is frequently misunderstood by educators, families, and the general public. Instead of being recognized as a summary of correctly answered questions, it’s believed to be a measure of an internal essence within the child that many call their learning potential. But there is little evidence that such an essence exists at all, let alone that IQ tests measure it.
I’m not aware of any educators who believe that test scores reflect an “internal essence within the child,” whatever that means.
I’m also not aware of anyone in K–12 who characterizes IQ specifically as a measure of “learning potential,” whatever that means.
So when they say “there is little evidence that such an essence exists at all,” they are technically correct—there is indeed no evidence of this “essence” that no one actually believes in or even talks about.
But their implication here is clearly that intelligence does not exist, which is false—as the article repeatedly admits, mischaracterizes, and downplays:
You sometimes hear, “Scoring well on an intelligence test only means you’re good at taking intelligence tests.” That’s not true. Good performance on intelligence tests predicts positive outcomes in a wide variety of other domains. Higher scores on intelligence tests predict better grades in school and better job performance in a variety of careers.5 At least within North American and European cultures, intelligence tests predict success for everyone, regardless of income, wealth, or gender.6 Even though intelligence tests don’t explain why some people do better than others in school or on the job, they are effective at predicting who will perform better.
Perhaps this is all going over my head, but it sure seems like intelligence is a perfectly logical explanation for why “some people do better than others in school or on the job.”
This pattern of grudging acknowledgement that intelligence matters, coupled with an immediate denial that it exists, is repeated throughout the article:
But an intelligence test is not some kind of mental X-ray machine, identifying an inner quality that explains people’s performance in the real world. IQ tests are a description of the fact that some people are more accurate thinkers than others, not an explanation of why they are. This is the non-essentialist conception of intelligence: An intelligence test score is a statistically sophisticated summary of a person’s tendency to answer questions correctly.
Again, I’m not a psychologist, but it seems obvious to me that the “inner quality that explains people’s performance in the real world” is intelligence—a concept everyone is familiar with and understands reasonably well.
Obviously we should ensure that every individual has opportunity and dignity, regardless of their intelligence. We should not make too big a deal out of it, just as we don’t make too big a deal of, say, height.
But I don’t see how it serves students to deny that intelligence exists as anything other than a sometimes-useful fiction.
Of course, there are many other factors that contribute to learning, lifetime earnings, and other outcomes, but intelligence is undeniably an important factor, as the article acknowledges:
You have no doubt noticed that some children learn faster than others, can comprehend more difficult concepts, and are therefore easier to teach. Everyone knows this; we perceive it in daily life outside of schools too. We expect that children and adults are valued and respected regardless of how quickly or easily they learn, but the differences are there for anyone to observe. Understanding these differences may help us teach more effectively.
Yet they repeatedly decline to directly acknowledge that intelligence is real or explain how it can help us teach more effectively.
Measuring Intelligence As A Property of the Body
Cognition happens in the brain. Knowledge is stored in the brain. The brain is a part of the body, and bodies have many properties that are measurable.
Measuring intelligence is tricky, and historically it was often done for less-than-noble purposes, with many pseudoscientific dead ends like phrenology.
But over the course of the 20th century, scientists figured out how to measure intelligence in ways that are valid, reliable, and useful.
Psychologists have now spent more than a century arguing over how to measure intelligence and what precisely it is that we’re measuring. (A good illustration of the complexity of the debate is the g factor.)
There’s a great deal we don’t know about which specific genes and other factors contribute to intelligence and how these factors interact.
But we can and do measure intelligence, and it turns out that these measures are, as Willingham and Turkheimer acknowledge, highly predictive of important life outcomes.
So it would be very strange if these measures didn’t reflect some real underlying property of the human body. Some of what we know beyond dispute:
Intelligence is highly heritable—on the order of 0.7 in adulthood—but not fixed
A wide variety of environmental factors—nutrition, exposure to toxins, parenting, and more—affect intelligence
Education has a significant positive impact on intelligence—about 1-5 IQ points per year of education
In what sense does intelligence matter for learning, and why does it matter that we understand it properly?
Speed of Learning And Time
One major implication of intelligence is that some students learn faster than others, as the authors acknowledge several times.
This is inconvenient in educational settings where we’d prefer to teach everyone everything at the same pace.
I don’t know of any educators who believe, specifically, that intelligence places a hard ceiling on what any specific student can learn. But obviously intelligence helps, and kids who struggle often struggle due to real cognitive differences, not “essentialism.”
Willingham and Turkheimer conclude:
Making significant improvements in anyone’s thinking is never easy, and it is more difficult with children who have had less success in the past. But it’s helpful to know that a low IQ score doesn’t equate to a hard-and-fast limit on what a child can achieve. And whether the child has a history of success or struggle in the past, the broad guidelines for future success are the same: Start as soon as possible, be comprehensive, and persist.
This is a great point, but shying away from the reality of intelligence can cause us to miss the key educational implication: some kids need more time.
I don’t think we need to obsess over IQ or do more IQ testing in schools. But we must broadly recognize that some students need more time to learn than others.
We have a limited amount of time with our students, and because they learn at different rates, we must make real trade-offs in how we spend that time.
For example, if we want to ensure that all students are fluent readers by the end of elementary school, using time the same way for all students is unlikely to work.
Some students will learn to read largely on their own, while others will require not just strong Tier I instruction but intensive support from a skilled reading specialist.
Sending Teachers the Right Message
This article isn’t just a blog post; it’s a featured column in American Educator, which is sent to hundreds of thousands of teachers each quarter. It’s essential, then, that it convey accurate, useful information to teachers.
Puzzlingly, Turkheimer and Willingham open with this assertion:
A better way to think about an IQ score is as a snapshot of achievement now, rather than future potential. This conceptualization offers a better lens for how we might enable all children to answer more questions correctly—that is, to raise their IQs.
I don’t think it’s our goal to help students score higher on IQ tests, which generally don’t assess the kinds of knowledge or skills we teach in school.
It’s our goal to help students learn.
Intelligence, rather than reflecting what students currently know, indicates the approximate rate at which they are likely to learn for the foreseeable future.
When we have students who are clearly struggling with learning, we should not just say “Oh well, it’s not like intelligence is their ‘essence’ or anything!”
Instead, we should proactively plan to provide the time and support our students will need to be successful.
Related:
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An enduring criticism of growth mindset theory is that it underestimates the importance of innate ability, specifically intelligence. If one student is playing with a weaker hand, is it fair to tell the student that she is just not making enough effort? Growth mindset – like its educational-psychology cousin ‘grit’ – can have the unintended consequence of making students feel responsible for things that are not under their control: that their lack of success is a failure of moral character. This goes well beyond questions of innate ability to the effects of marginalisation, poverty and other socioeconomic disadvantage. For the US psychiatrist Scott Alexander, if a fixed mindset accounts for underachievement, then ‘poor kids seem to be putting in a heck of a lot less effort in a surprisingly linear way’. He sees growth mindset as a ‘noble lie’, and notes that saying to kids that a growth mindset accounts for success is not exactly denying reality so much as ‘selectively emphasising certain parts of’ it.
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—Carl Hendrick, in a 2019 article on growth mindset
https://aeon.co/essays/schools-love-the-idea-of-a-growth-mindset-but-does-it-work
A few random responses:
As a teacher, I have encountered plenty of teachers who believe something along the lines of, "some students are just smarter than others," and don't look at intelligence as malleable.
I think something Willingham and Turkheimer get at is that what we think of as intelligence is really an emergent property. It is a combination of genetics, environmental variables we understand (poverty, trauma, nutrition), environmental variables that we don't, prior knowledge, motivation, and more. It's important not to be essentialist about this because it's so complex.
I don't think it's fully accurate to say "some students just learn faster than others." Learning speed is a function of teaching. If we give students a strong program of synthetic phonics, gaps in learning speed will be smaller than if we teach through balanced literacy nonsense. Again, let's not get essentialist. With high-quality teaching, we can influence the interaction between intelligence and learning.