On April 9th, a conversation between Ezra Klein and Sam Harris was published with the initial goal of debating the science underlying IQ and race differences. The conversation quickly was derailed as it descended into topics of social policy, bias, honesty, slandering, and identity.

One of the most important aspects and best aspects about science is that scientific claims are empirical. That is they make specific predictions and are subsequently verifiable by observation and data. The issue with this conversation is that at no point was a specific empirical scientific claim made and then debated. Rather, abstract ideas were tossed around which lead to both parties talking past each other.

However, in an email conversation, Harris put forward 5 empirical claims:

Human “general intelligence” is a scientifically valid concept. IQ tests do a pretty good job of measuring it. A person’s IQ is highly predictive of his/her success in life. Mean IQ differs across populations (blacks < whites < Asians). It isn’t known to what degree differences in IQ are genetically determined, but it seems safe to say that genes play a role (and also safe to say that environment does too).

The first three are generally fine (although, they are way more vague then they ought to be). The fourth statement, however, is objectionable on scientific grounds and the fifth statement provides the reasoning for that objection.

Mean IQ differs across populations (blacks < whites < Asians).

This fourth premise is missing a very important word – ‘current’. That is, the claim should be that ‘Current Mean IQ differs across populations (blacks < whites < Asians)’. It is this missing word that is pivotal in the disagreement between people like Ezra and Sam.

I should also mention that black, white and Asian are such nebulous and generic concepts that they make the premise non-empirical. For example, where does one place people that are Mixed race? How does one make sense of the differences between groups of the same ‘races’? How does one reconcile the fact that Ashkenazi Jews, who are white, tend to have the highest mean IQ. Ultimately, this, along with some questions and issues surrounding the conceptualization and measurement of IQ (which historically was a large problem, and while less of a problem now, is not without valid criticisms) are huge problems with this entire discussion that could have and should have derailed it before it even starts; but I’ll leave that for another post. For now, I’ll begrudgingly assume that IQ is a valid measure of everything we care about in terms of intelligence and that races can easily be divided into three categories (just writing that out makes me upset that the conversation even got started).

Ultimately, the problem is that during the exchange between Murray and Harris, Murray makes the claim that the differences are immutable, a point that Harris doesn’t contest. That is, Murray suggests that even if the environment was completely neutral, blacks would still be at the bottom of the IQ hierarchy. This is where Murray, and subsequently Harris, move from making scientific empirical claims to ‘peddling junk science’ and arguably move towards the ‘justifying of bigotry and racial inequality.’

It isn’t known to what degree differences in IQ are genetically determined, but it seems safe to say that genes play a role (and also safe to say that environment does too).

This fifth premise provides exactly the reason why the fourth claim is not valid. Because it isn’t known to what degree, differences in IQ are genetically determined, one cannot make a claim about Mean IQ differences across populations.

Coupled with this problem, may be an issue understanding the interaction between genes and environment. Harris has made a comment suggesting that intelligence is somewhere around 50% genetic and 50% environment but grouping a complex interaction into percentages like this is nonsense. It would be like asking what percentage of a bread (e.g. the taste, texture, etc.) is the ingredients and how much of it is the heat in the oven? Bread is 50% ingredients and 50% heat makes as little sense as 50% genetic and 50% environment. Rather it’s a complex interaction between the two. While you can sometimes point out specific circumstances, e.g. baked too long or at too high a temperature, or forgetting to add yeast (just as you can sometimes point to specific circumstances, e.g. malnutrition or a specific genetic mutation), for the most part, one must understand the interaction between the two (e.g. if you add less yeast, you have to bake it for longer)[1]

Ultimately, it may be when environments are neutral, ‘blacks’ actually have the highest IQ. It might also be the case that different environments interact with different sets of genes, such that the best environment for one group of individuals is not ideal for another group of individuals.

It would be like asking what percentage of bread is the ingredients and how much of it is the heat in the oven? Bread is 50% ingredients and 50% heat makes as little sense as 50% genetic and 50% environment.. Rather it’s a complex interaction between the two.

More Science is Needed

As cliché as it is, questions regarding race and IQ simply don’t have the data yet for any satisfactory answer and any attempt to present an answer is going to be confounded by numerous historical and environmental factors. While Harris is right that we need to be fine with talking about controversial scientific issues, we also can’t be naïve about the implications that people may draw from the data, particularly when the implications don’t actually reflect the data.

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[1] It should be noted that this is true regardless of whether one wants to say has a strong genetic component – 50% genetic and 50% environment is just as meaningless as 90% genetic and 10% environment.