Jordan Peterson’s IQ

I came across some things that Jordan Peterson has been saying about IQ and I have been giving it some thought. Petersons’ argument is persuasive and, I think, mostly correct but I also feel that it is not quite right, so I have been trying to work out why.

Peterson makes some points about IQ that I think are worth considering:

  1. The results of IQ tests form a normal distribution, symmetrical about the mean.
  2. IQ is a measure of cognitive ability.
  3. It is a measure of the facility with which individuals can carry out abstract reasoning.
  4. People cannot learn to improve their IQ.
  5. The average IQ scores are different for different races, for example, Jews score much higher than the average of the population at large and Blacks score lower.
  6. The bottom 15% of the population, according to IQ score, cannot be productively employed.
  7. There is a strong correlation between IQ score and the ability to function in specific occupations.
  8. The highest average score among different academic faculty disciplines is physics and maths.

Point number 1 tells us that this is a scientific and, therefore, purely objective concept with real life implications. So, IQ is not just a concept within the episteme it is an objective fact to be found ‘out there’, like Mount Vesuvius or one of Peterson’s beloved lobsters. In fact, says Peterson, IQ is the most reliable construct in the whole of the social sciences. Having established this, we had all better sit up and take notice because this is something that we cannot afford to ignore.

Points 2 and 3 are really the same point so let’s take them together. Cognitive ability and abstract reasoning are things that people do, like lifting weights or running fast round a track. If you ask some people to see what the heaviest weight is they can lift, you find a similar distribution to IQ. So, we don’t really have to know what this particular ability is, apart from the ability to do IQ tests, because point 6 says that it correlates with something that we can detect in the real world, which is occupations, though I don’t feel sure that I know what exactly this cognitive ability is; it doesn’t, for example, seem to involve any people or communication skills. At this point we should, of course, take care because correlation is not the same thing as causation, though Peterson implies that in this case it is. For example, it could be that there is a third factor that is independently causing both IQ and occupation.

Now, it is point 4 that makes me the most uneasy. What Peterson says is that ‘you cannot teach anyone to do anything’. This implies that he believes that IQ scores are something that people are born with, stay constant throughout life (except some predictable variation with age) and are unaffected by other factors such as education or environment. However, Michael Flynn says that IQ scores over whole populations have changed over long periods of time (Flynn, 2013). The average score for an IQ test is set to 100 and Flynn claims that what scored 100 back in the days when IQ tests first came along, in the early twentieth century, would only score at about 60 on the present-day metric. If Flynn is correct, it means that IQ tests are not testing something immutable. Another consequence of Flynn’s assertion is that, if it is correct, IQ is an attribute of society as well as of the individual.

Flynn argues that IQ has risen because of a greater need in the modern workplace for the skills of abstract reasoning which has driven the education system to cultivate these skills (Flynn, 2013). So, Flynn believes that our forebears had the latent ability to exhibit high IQ scores, but their environment discouraged it because abstract thinking was not useful to them. If Flynn is right, then it leaves open a possibility for interpreting point 5 in a constructive, rather than fatalistic, way. Is it not possible, in fact likely, that the difference in IQ scores between races is largely due to habitus (Bourdieu, 1984) rather than DNA? If this were true, IQ scores are not immutable but can be changed, albeit slowly and with difficulty.

This brings me to the flaw that I perceive running through Petersons’ work: he is a psychologist. As Mary Douglas once observed (Douglas, 1986), psychologists institutionally forget that people are not just individuals but are part of groups. To be clear, my greatest problem with Peterson’s work is that he has no institutional theory in which to contextualise his conclusions about the individual. If there were an institution theory included here, it might be apparent that there are other explanations that do not rely on the old individual and their fate dichotomy. This problem is exacerbated by a relentless application of quantitative methods which can only give snapshot views of phenomena but are nearly useless for explaining causation.

I suggest that differences in IQ scores between races may be largely due to habitus and I use the word largely because, I suggest, there is no way of knowing, at the present state of research, what the extent of these differences are caused by habitus and what by genetics. At this point racial politics rears its ugly head and people with deeply held assumptions go into battle with one another.

The political consequences of this debate bring me to point 6. Peterson argues that because the US military believes that people who have IQ scores below 85 are not worth employing that this must be true. Well, Prof Peterson has more faith in the rationality of institutions than I do and this, indeed, sounds like a rational actor argument from economics. I suggest that a healthy dose of scepticism is called for on this point. However, I think that he has hit upon a huge political problem for the advanced economies: what to do with people who are chronically unemployed. As Peterson says, the political right insists that they should be forced to work and try harder and the political left believe that anyone can be trained to do something. He suggests that they are both wrong and I have some sympathy with this view. I suspect that the truth is that, although it is correct that these people could be trained to do something, the effort that would have to be put into changing the way that they think and interact with the world would be prohibitively expensive and that it is cheaper to just to pay them welfare.

Peterson’s point 7, in my list, asserts that IQ is directly and reliably correlated with occupation, with the bottom 15% IQ scorers being chronically unemployed and there being a hierarchy of occupations according to IQ scores above them. I have no reason to dispute this assertion, but I think that we must be careful about the possibility of the post hoc ergo propter hoc fallacy creeping in here. Rather than IQ causing occupation, perhaps there are factors which bring about both IQ and occupation choice, such as habitus, for example. Habitus has been shown to play a part in the early development of mathematical ability (Turvill, 2016) so perhaps it plays a part in determining IQ, as Flynn’s findings suggest.

Finally, Peterson’s point 8, seems to put the whole debate into perspective. What is IQ, anyway, and why does it matter? It seems to me only to matter because it is commonly used pseudo-scientifically to influence political debate: if you don’t like a group of people, you can label them as irredeemably ‘stupid’ and legitimate the slander with science. At the other end of this dimension, the fact that the science and physics faculty score the highest on IQ tests underlines the fact that IQ, whatever it is in reality measuring, does not measure something that is exclusively useful compared to other abilities. Although I have great respect for my colleagues in the maths and physics departments, this is not the first place I would look if I wanted to find someone to run my company. IQ measures a skill at dealing with a certain kind of abstraction which has little to do with people skills, such as getting them to work effectively together.

Peterson shows a little naïveté, I think, on this point when he is invited to speculate about the IQ of Donald Trump. He thinks that Trump probably has a high IQ because of all the complex activities he has been engaged in. In another place, Peterson says that organisations are full of people who are conscientious along with “a few psychopaths thrown in”. My own experience is that psychopaths are good at presenting themselves as people who have high IQs when they do not; what they do have is a kind of cunning that enables them to read others for the sole purpose of manipulating them. I suspect that Trump is one of these and that Peterson, along with many others, has been duped.

In the end, I would argue that Peterson places too much emphasis on IQ. It is a fascinating plaything in the world of the psychologist but in the rest of the world it is not so useful and can, at worst, become a dangerous smokescreen for intolerance. However, despite some reservations about some of Peterson’s opinions, I want to end on a positive note. Peterson has rightly become a celebrity because he is a moderate voice in an increasingly unhinged world and because he is not afraid to talk about issues that others prefer to avoid.


Bourdieu, Pierre (1984). Distinction. Abingdon, UK: Routledge and Kegan Paul.

Douglas, Mary (1986). How Institutions Think. New York: Syracuse University Press.

Flynn, Michael (2013). Why our IQ levels are higher than our grandparents’. Available at:, Accessed on: 22/04/2018.

Peterson, Jordan (2017). Personality 18: Biology & Traits: Openness/Intelligence/Creativity. Available at:, Accessed on: 22/04/2018.

Peterson, Jordan (2018). Jordan Peterson @ Lafayette, A Conversation and Q&A, Full Event. Available at:, Accessed on: 22/04/2018.

Turvill, R.A. (2016). How are young children developing number sense, post national numeracy strategy (Doctoral dissertation, Brunel University London).