The "Science" of Human Intelligence: A Skeptical View

Howard Gardner © 2024

Popping up on my desktop screen is a 2023 book, The Science of Human Intelligence (Second Edition). Given my decades-long interest in the topic, I decide to look at the book. Fortunately, since the purchase price is over $100, the Harvard Library has a copy and I am able to borrow it.

Having my share of vanity, I look for my name in the index. There is only one entry—pp. 18-19. After a brief paragraph, my ideas are dismissed as having “no objective scientific evidence.” There is no citation of my several books on the topic, including the perennial bestseller Frames of Mind: The Theory of Multiple Intelligences.

Robert J. Sternberg

I say to myself, somewhat defensively, “I am not really a psychologist and don’t present myself that way. How about Robert J. Sternberg, another critic of the standard view of intelligence? He is a “real psychologist”—Bob was president of the American Psychological Association—does he get more air time?” Alas, no more lines in the book, though there is a reference to one short article by Sternberg in the journal Intelligence called “Teaching about the Nature of Intelligence.”

Interestingly, in the same short introductory chapter, more space is devoted to the late Stephen Jay Gould’s book The Mismeasure of Man—indeed, to two editions of the book (1981, 1996). But going beyond sheer dismissal, the authors pick a fight: “Gould had many facts just plain wrong and worse, when confronted with detailed technical reflections of his key points…Gould declined to correct his mistakes or modify his opinions.” Alas, Steve Gould, who was a friend, died in 2022 and so, cannot defend himself.

Well, enough defensiveness. What do I make of this textbook of over 400 pages?

Alfred Binet

One of the great advances in psychology was the creation, well over a century ago by the French psychologist Alfred Binet, of a short test—one that could be given to young French students to indicate how they would likely fare in a school of that era. The IQ test, as it soon came to be called, accomplished this task reasonably well. And as all readers of these words know, the IQ test—and its relatives, like the SAT or the GRE or the Raven’s Progressive Matrices—have been used thereafter to classify individual test-takers in terms of their intellectual strength.

The text that I leafed through is an up-to-date report on what we know about the IQ test in its various forms—different models of intelligence, various approaches to administering and interpreting the tests, major cognitive factors contributing to intelligence, possible brain and genetic bases thereof. And, presumably of most interest to most readers: 1) the kind of life-success that can be predicted and 2) putative differences among populations (e.g. racial, ethnic, socio-economic groups), as reflected by their tested (psychometric) intelligence. So long as you are interested in this topic and these questions, this text will give reasonable up-to-date information on these issues.

So far, so good.

The line is drawn with the word “scientific.” By accident, or by intent, the authors of the text rule out-of-bounds any effort to write about intellect that does not follow their rules of carrying out science, or indeed any form of scholarship, on the topic of intellect.

And here is where I draw my line.

When I began to study human cognition a half-century ago, I had no intention to critique standardized tests—indeed, unlike Bob Sternberg, I did well on them. But I did not think that the only way to study the human mind was by creating short-answer tests and then documenting their correlations to various school and life outcomes. Instead, in what I now term a work of synthesis rather than of science, I drew on various kinds of information and forms of knowledge, ranging from neurology and genetics to anthropology and history, and tried to ascertain the spectrum of cognitive capacities that characterize our species.

Some of these “multiple intelligences” lend themselves to short-answer tests—linguistic, logical-mathematical, and spatial—and so, not surprisingly, those are the ones included in most tests of intelligence. Others, which I felt were equally important for a productive life in our world, are far more difficult to ascertain through paper-and-pencil instruments. These constitute the remaining intelligences—specifically musical, bodily-kinesthetic, interpersonal, intrapersonal, naturalistic, and perhaps 1-2 others.

Borrowing from the Bard, I was not trying to bury standard IQ intelligences, I was trying to praise the remaining ones. And as a bonus, rather than testing in order to classify and rank-order people (and alas, that’s the thrust of the text that I reviewed), I preferred to nurture the range of intelligences. I wanted to document what life opportunities might open up—in schools, where the bulk of my work has been, but also in the wider world—acknowledging that there is more to life than a certain kind of test and a certain kind of educational institution.

Now, of course, with increasingly intelligent large language instruments—notably ChatGPT—when it comes to assessment, placement, and life opportunities, almost all bets are off.

One last point.

If you are interested in what’s known about the factors involved in standard intelligence testing and the variables that correlate with the range of IQs, this text will answer your questions reliably. But if you want to know the sub-text of this text, let me quote for you two passages which receive headline attention therein:

Robert Plomin

Robert Plomin: “The most far-reaching implications for science, and perhaps for society, will come from identifying genes responsible for the heritability of g (general intelligence).”

Douglas Detterman: “Intelligence is the most important thing of all to understand, more important that the origins of the universe, more important than climate change, more important than cancer, more than anything else.”

Douglas Detterman

Forty years ago, I wrote about intelligences, but ever since, my colleagues and I have been studying what it means to be a good person and to do “good work” (see thegoodproject.org and the many books, articles, and technical reports listed there).

The world is not going to be saved by smarter people—if it is to be saved, it will be saved by persons who are trying to use their wits for the sake of others.

REFERENCES

Haier, R. J., Colom, R., & Hunt, E. (2023). The Science of Human Intelligence (2nd ed.). Cambridge: Cambridge University Press.

Are Brain Surgeons and Rocket Scientists Really Smarter?

A recent study in the British Medical Journal has found that brain surgeons and rocket scientists perform no better than laymen on 12 online tasks using the Great British Intelligence Test (GBIT).

Howard Gardner was asked by The Daily Telegraph for his thoughts on this finding. He responded as follows:

"The standard IQ test is a reasonably good predictor of how one will perform in a standard school," says Gardner, now Hobbs research professor of cognition and education at Harvard. 

 "But once you move away from performance in a scholastic environment, other abilities come to the fore. IQ tests tap linguistic and logical-mathematical abilities. But you need assessments of other intelligences to predict who will become an effective therapist or sales person (personal intelligences), athlete or surgeon (bodily-kinesthetic intelligence), composer (musical intelligence), sculptor or architect (spatial intelligence), biologist (naturalist intelligence)." 

 As a result, Gardner believes we "need to talk about intelligences, rather than intelligence, and about personality traits and motivational factors if one wants to understand fully the nature of surgery or rocket science." 

The full article is available here.

Mindy Kornhaber: Trump's Intelligence

Trump’s Intelligence

Mindy Kornhaber

Whether one prefers or deplores Donald Trump, the press is like a moth to his orange flame. As a result, he’s become the steadfast set of pixels on many of our screens for the better part of a year. How is it that someone who has never held public office and has evinced ignorance on matters of policy (e.g., abortion, a wall paid for by Mexico) has completely outpaced his Republican rivals? Is it a sign of genius? If so, what sort? I consider Trump’s intelligence through both a traditional IQ lens and the theory of multiple intelligences (MI).

IQ

According to a pre-candidate Trump tweet, “…my I.Q. is one of the highest -and you all know it!” (May 8, 2013). This tweet, like so many other Trumpnouncements, is hard to verify. Estimates online peg his IQ between125-156, but these scores don’t rest on factual bases or rigorous methodology. Correlates of a high IQ, e.g., high SAT scores, have not been forthcoming or available. So, the short answer is we don’t know what Trump’s IQ is. If Trump knows his own IQ and knows that it’s “one of the highest,” it’s reasonable to think he would release a verifiable score report.

But let’s say, for the sake of argument, Trump’s self-assessment is on the mark. Would a high-IQ equip Trump to advance the well-being of people throughout the country, and, indeed, the world? It turns out that measured intelligence and the spine required to serve the common good are usually kept in separate psychological boxes. (The Good Project, at thegoodproject.org, is an initiative spearheaded by Howard Gardner that seeks to elucidate how to achieve “the good” for society). Even if Trump's IQ stacked up, it can’t gauge whether he’d act ethically in office. Several Nazi leaders had IQs above 130 (c. top 2.4%). I keep a list of their scores posted outside my office. The point: IQ is not a measure of goodness, values, or the capacity to understand human worth and protect human dignity.

If Trump does have “one of the highest” IQs, such a score is not needed for the nation’s top job. Nearly everyone who manages the complexities of high-finance building projects in New York or a national political campaign (or gets just an undergraduate degree, without honors, from Wharton as Trump did) will have an IQ good enough to be president, i.e., one reasonably above the 100 average. An exceptionally high IQ is not required to do important and complex work: Neither Watson nor Crick -- Nobel laureates for discovering DNA -- hurtled the genius low bar of 130 IQ. And longitudinal research on the Termites (high-IQ children initially identified by IQ guru, Lewis Terman) underscores that high IQ does not foretell unusual success. The point: If Trump has “one of the highest IQs,” it doesn’t up his qualifications for president.

Even if Trump had the highest IQ in the candidate pack, it would not indicate how well he’d perform relative to his rivals. Statistically speaking, the population of candidates is too small and the variation in their scores is likely too narrow to permit such prognostications. Generally, IQ has a moderate degree of 'predictive validity' with occupational status (e.g. sales clerk v. accountant v. rocket scientist). However, it does not predict performance within occupational status. That is, IQ doesn’t help predict who’ll be a better accountant or president.

Multiple Intelligences (“MI”)

That IQ doesn’t predict performance within a given occupation indicates that success in real work requires capacities not surveyed by intelligence tests. This is partly because intelligence testing was invented with the rise of mass education in order to examine and predict performance in school settings at the time (in the early 20th century). In such settings, problems are solved by individuals, have right and wrong answers, and focus on language, math, and sequential logictasks. Intelligence tests likewise examine, and are best at predicting, these sorts of performances. Underlying such performances is supposedly one problem-solving ability (or variations thereof), called ‘general intelligence.’

Rather than seeking to explain and predict school-like performances, Howard Gardner developed MI to shed light on the abilities ("intelligences") that enable people "to solve problems or fashion products that are valued in one or more cultures." So, MI provides a more 'real world' (v. e.g. classroom) perspective on human problem solving.

Gardner's analyses of research from his own fields of cognitive development and neuropsychology, and from linguistics, comparative psychology, anthropology, and psychometrics has led him to posit at least eight, relatively autonomous intelligences: linguistic, logical-mathematical, spatial, musical, bodily-kinesthetic, intrapersonal, interpersonal, and naturalist. Intelligence tests seek to assess the first three (at most). Standardized school tests commonly assess only the first two.

If true, Trump’s self-reported high IQ indicates that he has the linguistic intelligence to speak persuasively to his political supporters and the logical-mathematical intelligence to determine when to seek bankruptcy protection. However, IQ scores say nothing about forms of savvy essential for political life and leadership: intrapersonal and interpersonal intelligences.

Trump -- and anyone aspiring to high office -- believes he can do better than the next guy or woman. That kind of belief will be more or less grounded in intrapersonal intelligence. This intelligence enables individuals to understand their own feelings and motivations and to have an effective working model of themselves.

On the intrapersonal front, Trump may have an understanding of his own feelings and motivations. He is evidently motivated to garner the spotlight and hold it by tossing out comments that violate common practices of civil and political speech. This has led various psychologists to label him a narcissist (see Vanity Fair, November 11, 2015 online).

However, what is especially problematic is the chunk of Trump’s intrapersonal intelligence entailing "an effective working model of oneself." He apparently thinks his skillset as a popular entertainer or businessman fits him to be president of a democracy whose Constitution was designed to check and limit power. Yet, "You're fired!" is not a workable presidential directive to Congress or the Supreme Court.

Interpersonal intelligence enables individuals to understand others' motivations and needs. As Trump struts down the runway toward the November election, he will have to rely more on interpersonal intelligence than his work until now has required. Two aspects of interpersonal intelligence are important.

First, to get elected, it’s essential for Trump to understand voters’ needs and motivations, so that he can persuade them (as well as delegates) that he’ll act in line with their interests. Trump has shown he has enough interpersonal intelligence to get more votes than his Republican rivals. He understands that parts of the Republican base feel pushed off the economic ladder (perhaps by immigrants) or have been ignored by (weak, bought) politicians. These days, he's seeking to get votes by identifying himself/his candidacy as a victim and outsider, akin to those in his base who feel marginalized. He also understands that violating typical modes of speech appeals to many people who are sick of politics as usual. However, if Trump actually wants to win (and, of course, he’s a winner not a loser!), he’ll have to use his interpersonal intelligence to gain support from those who have not yet found his modus operandi appealing (and/or Hillary will have to stumble). He’s a good salesperson for himself. Perhaps he’ll succeed.

Second, were Trump to be elected, he would actually have to work in a sustained way with people whose desires, intentions, and motivations are often at odds with his own. This is something for which he’s evinced little inclination. For such work, he'd also need to draw on intrapersonal intelligence to understand that he must learn to work with people who have joint responsibility for governing. Despite being a “deal maker without peer” , he’d have to figure out how to “deal” with leaders of other powerful nations, even though their knowledge and experience in matters of world affairs far exceed his own.

In sum, it's not necessary to have an unusually high IQ to be a good president. Moreover, IQ doesn’t measure the intra- and interpersonal intelligences needed to run for office and succeed if elected. Trump has good enough interpersonal skills to get votes from his base of supporters. He may have good enough skills to grab the majority of the electorate in November. However, to be effective as POTUS, Trump would need exceptional interpersonal skills. Unfortunately, he shows inadequate capacity to take in others' perspectives, weigh them, and work constructively with people he can’t fire. He'd also need adequate enough intrapersonal intelligence to realize he’d enter the office without an effective working model to guide his actions in office. He’d have to seek to address that flaw, despite already perceiving himself as a great and amazing success story . Whatever his IQ, Trump’s gaps in inter- and intrapersonal intelligences are deeply problematic for the job he’s now seeking. They could also be problematic for the nation and the world.

Mindy Kornhaber is an associate professor at Penn State. She joined the faculty in 2001 after serving as a researcher at Harvard University for more than a decade. Her work draws equally from the fields of social policy and human development and focuses on two related questions: How do institutions and the policies surrounding them enhance or impede the development of individual potential? How can individual potential be developed both to a high level and on an equitable basis? For the past several years, she has been concerned with testing policies and their influence on educational equity and students' intellectual development. She is also concerned with assessment, educational equity, how theories of intelligence influence school practice, and school reform.

Is the Brain a Computer?

In June of this year, Gary Marcus, an NYU professor and contributor to The New York Times, published a piece entitled "Face It, Your Brain Is a Computer". What follows is Howard Gardner's response to this article.

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Notes by Howard Gardner

When I am describing my view of intellect,  I often contrast it with the standard view of intelligence. And I invoke a computer metaphor. The old view posits a single all purpose computer: if it computes well, you are smart in everything; if it compute poorly, well, you are out of luck—all cognitive doors are closed.

My view, in contrast, posits the existence of several computers.  Each computes a certain kind of information in a way appropriate to that computer.  And so the musical computer deals with sounds, rhythms, timbres,  harmonics, while the spatial computer deals with the arrangement of objects or movements in local or global space.  A corollary is that the strength (or weakness) of one computer does not entail similar or different evaluations of the strength of another computer. Person A can be strong in spatial and weak in musical intelligence;  person B can display the opposite profile.

Clearly, the invoking of computers is a metaphor.  No one believes that an IBM computer (or several) or a microchip (or hundreds) is literally located in the skull.  Rather, the argument between Marcus’ view, on the one hand, and my view, on the other, is whether it is more helpful to think of one all purpose computer, or several more specific and more dedicated computers.

An analogy may be helpful . We all learn about the world through our sense organs. But there is a big difference between the claim that all sensory organs work in basically the same way, and the claim that each sensory organ has evolved so as optimally to handle certain kinds of inputs in certain ways.  I find the latter view much more useful.

Marcus raises a broader question (“Does it make sense to think of the brain as a computer?”) and has a simple answer (“Yes it does”).  But as he himself points out, we now recognize different kinds of computer with different kinds of computations. MI theory simply extends this form of conceptualization to the variety of cognitive processes of which human beings are capable.

The Nature and Nurture of High IQ

Notes by Howard Gardner

It’s long been known that as one gets older, the genetic contribution to measured intelligence (IQ) is higher. Put concretely, the IQ of the 70 year old is more likely to resemble the IQ of his/her parents and grandparents, than the IQ of the 10 or 20 year old. But this study adds a new page to this chapter. It turns out that individuals with higher IQ actually have a longer period in which non –genetic (environmental) factors are significant, than those with lower IQs. As such, the study raises an intriguing possibility: Anything that we can do to raise IQ in young persons is likely to increase the length of time in which the effects of the environment (e.g. peers, mentors, experiences) are significant. And since we know that measured IQ has gone up a huge amount in the past century (see the Flynn effect), these results are a very hopeful sign.

To read the article in its entirety click here.