It’s hard to deny the grim entertainment value of the latest Trump spat. But the idea that an IQ score is just a bragging aid for egotistical politicians threatens to trivialize a genuine field of research. It doesn’t help, of course, that IQ tests hardly have a good reputation to begin with. Steeped in controversy, by far the most common reaction whenever the topic arises is the oh-so-droll refrain: “IQ tests only tell you how good you are at doing IQ tests!”
In fact, IQ tests tell us much more than that, as a mountain of evidence from the fields of psychology, sociology, neuroscience, genetics and epidemiology attests. For instance, we know that people who do better at IQ tests tend to do better at school, in work and in terms of their physical and mental health. On average, they even live longer — and this doesn’t seem purely due to education or social class. Studies continually appear in top neuroscience journals linking MRI measures (such as the overall volume of the brain) to IQ scores, and some of the first IQ-related genetic variants are now being uncovered.
Yet controversy around IQ tests and scoring remains. Some of it is due to the fear of immutability, or the worry that a low IQ score is set in stone, dooming a person to a life of failure and embarrassment. But this is misplaced. First (pace, perhaps, Trump) IQ is only one of a whole constellation of reasons (including hard work and sheer chance) that people get to where they end up in life. And as the writer Scott Alexander has recently noted, the findings discussed above are all averages and tendencies and trends at the group level: they absolutely don’t apply to every individual person who gets a particular score on the test.
Second, nobody would argue that IQ is strictly biologically determined: The environment still has a crucial influence. Indeed, scientists don’t all share the fatalistic view of many IQ critics; rather, a great deal of IQ research is focused on how we might boost people’s abilities. For example, we know that factors like iodine deficiency are linked to lower IQ scores (a brilliant charity, the Iodine Global Network, is dedicated to doing something about this) and growing evidence appears to show positive effects of education on IQ. Research continues on whether improved physical fitness, among other influences, might help older adults stave off the decline of their mental abilities as they age.
Another reason psychologists wince at self-satisfied crowing about IQ is that the tests can — in the right hands, and despite the immoral ways they have often been used in the past — serve a useful social purpose. After all, they were first invented in order to identify children who were in need of extra educational attention, and they can still serve that purpose today. A terrific study from last year also illustrated how IQ tests can level the social playing field, finding that the use of objective cognitive tests — as opposed to referrals from parents and teachers, who aren’t always reliable at spotting talent in certain groups — improves representation of poor and minority children in gifted education programs.
Treating IQ as a frivolous, point-scoring game makes it easier to write off all this perfectly serious research, and ignore the useful information we can get from cognitive tests. It contributes to the mistaken notion that IQ researchers are trying to sum up the worth of a person, rather than develop useful tools to understand the mind and identify different levels of ability. Most importantly, it fails to recognize something that should be obvious: That the mere possession of a high IQ score isn’t what matters. We don’t admire history’s great scientists, mathematicians, composers and artists because they were intelligent per se; we do so because they used their intelligence to produce something worthwhile in the world. Those who would bandy around their high IQ as if it in itself entitled them to respect should take note.