(Epistemic status: I think there’s a 75% chance that less intelligent people have at least a 20% higher relative probability of agreeing to racist or segregationist claims like “blacks tend to be lazy”. I think my explanation of this phenomenon is probably roughly right. I don’t think my explanation is very nonobvious to people with the right background knowledge; I just applied primitive evo psych reasoning to the problem and was happy with what came out.)

There seems to be evidence that dumb people are more explicitly racist than smarter people. Research on how political views correlate with intelligence normally finds the following things:

  • Less intelligent people are more likely to agree with explicitly racist statements like “Blacks tend to be unintelligent”, “Blacks tend to be lazy”, or “White people have a right to keep blacks out of their neighborhoods if they want to, and blacks should respect that right.”.
    • One paper found that 21%, 43%, and 29% of people in the bottom third of intelligence agree with those statements, while 14%, 33%, and 18% of people in the top third of intelligence do (Table 3, Wodtke 2016). So this effect isn’t totally overpowering, but is pretty strong.
  • Less intelligent people are more likely to endorse that flavor of comment about homosexuality, gender roles, and so on.
  • This effect is detected only in socially conservative attitudes, not other conservative attitudes–Republican voters are probably slightly smarter than Democrat voters on average (Carl 2014), as well as better informed about the world in general and current events. And dumb people are no more likely than smart people to support some racially redistributive policies like tax breaks for businesses in predominantly black areas.

Why do we find that effect of intelligence on social conservatism? I find the answers traditionally offered by researchers and writers pretty condescending and unconvincing. It’s common for them to say that conservatism is more attractive for less intelligent people because it suggests a simpler view of the world, which is comforting for their tiny minds. But this doesn’t really feel sufficient to me. Human behaviors were optimized by evolution. If humans have a tendency to err in a particular direction (by being too mistrustful of weird strangers, or too trustful), then the tendency generally has a fitness advantage, and it’s often productive to try to investigate what that fitness advantage is.

Racism as a strategy

I think racism is an evolved behavior which makes more sense if you’re less intelligent, and our brains are built to adapt our level of racism to many aspects of our situation, including how dumb we are.

Statistical discrimination and broad generalizations make more sense if you’re worse at accurately evaluating things. If you’re good at accurately estimating the qualities of people by interacting with them and using your judgement, then it isn’t very useful to make judgements based on their race. But if you’re not very smart, then it’s a better idea to learn heuristics and use them.

Also, if you’re less intelligent, you should be more inclined to be suspicious of people you don’t know. One risk of making decisions with explicit reasoning is that someone much smarter than you can trick you. A sensible defense against this is to be suspicious of people who might be trying to trick you. People in your outgroup are more likely to be trying to trick you, because you’ll have less social recourse if they scam you. This strategy is more useful if you’re less smart. (I could phrase this hypothesis as “dumb people should be more prone to engage in epistemic learned helplessness”.)

More generally, if you’re less smart, you should be more reluctant to approve of social changes based on verbal arguments. So we should expect less intelligent people to hear the arguments for things like same-sex marriage, and then say “I don’t know, it just seems wrong and your arguments don’t convince me.” (This fits with the evidence that higher IQ people have more Openness to Experience.)


This explanation predicts that social conservatism will generally be unfashionable among intellectuals, because social liberalism will consistently be an effective signal of intelligence. I don’t know how universally this is true.

One final mystery: How are there so many dumb liberals, if dumbness inclines you to social conservatism? My guess is that dumb liberals really don’t see gay people and black people as their outgroup, so these factors don’t affect them. And in their subcultures, gender roles have already shifted in the direction that they want society as a whole to change, so this doesn’t feel scary to them.

Why do I propose that humans adapt our level of racism to fit our situation, instead of thinking that racism is determined by genetics? I’m mostly just believing “The Moral Animal”. It argues that choosing strategies based on your experiences while you’re a child is more effective than doing it based on genes, because that’s more a more adoptable strategy. I haven’t looked into how heritable explicitly racist views are, but any research on that would obviously have to control for intelligence for it to be worth anything.

“Are Smart People Less Racist” and other papers

Let’s review Wodtke’s 2016 paper “Are Smart People Less Racist?” in detail, then briefly look at a bunch of other papers. It found that people who do better on the GSS vocabulary test, which is often used by social psychologists as a proxy for intelligence, were less likely to agree with explicitly racist statements.

This isn’t just smarter people being more liberal, or smarter people being more inclined to say liberal-sounding things. Smarter people were no more likely to agree with supposedly leftist policy prescriptions:

But, despite these liberalizing effects, whites with higher cognitive ability are no more likely to support open housing laws, special government aid for blacks, tax breaks for businesses to locate in largely black areas, and targeted spending on predominantly black schools, and they are significantly less likely to support school busing programs and preferential hiring policies, compared to their counterparts with lower cognitive ability.

This makes sense to me–I think that both conservatives and liberals can be reasonable people, and smart conservatives who oppose these policies probably do so out of a legitimate disagreement with those proposals, rather than because they’re really racist deep down.

It makes less sense to Wodtke, who writes:

These seemingly paradoxical findings challenge the enlightenment hypothesis that higher cognitive ability promotes a sincere commitment to racial equality.

Principal Skinner: are my leftist policy ideas really not unambiguously correct? no, my opponents must be secret racists

Later, he considers the possibility that smarter people are opposed to these policies because they’re more libertarian, instead of just being secretly racist. He notes that in his data, smarter people are more likely than less intelligent people to have environmentalist attitudes. He takes this to be evidence that smarter people are not actually more libertarian. I appreciate that he did this, but I really wish that instead of this he’d investigated people’s feelings towards non-racially-charged redistributive policies–I think that that would have provided much more relevant evidence. As it is, I don’t feel like it’s very strong evidence against my hypothesis that smart people might legitimately think that some of these policy ideas aren’t very good.

I also have a bunch of minor methodological issues with the paper. His respondents filled in their answers on a Likert scale, which were recoded as a binary variable. That is, people who were neutral on things like “Giving business and industry special tax breaks for locating in largely black areas” are coded the same as people who are strongly opposed. I don’t know if this is standard practice in social psychology but it seems foolish to me. Also, social desirability bias could have affected people’s enthusiasm about answering affirmatively to questions like “Would you object to having a coworker of a different race?”. Also, I know I often defend the legitimacy of intelligence tests, but using a vocabulary test as an intelligence test seem kind of sketchy–perhaps it’s picking up on some cultural factors as well as intelligence.

Here are some of the other papers I looked at:

  • Hodson and Busseri (2012), “Bright Minds and Dark Attitudes”. This paper finds, with a methodology I find weak (the intelligence test was done twenty years earlier than the racism test), that lower intelligence predicts social conservatism which predicts explicitly racist beliefs, but intelligence doesn’t predict racism given social conservatism. This matches the results here. This paper doesn’t check how intelligence affects race-related political questions.
  • Dhont and Hodson (2014), “Does Lower Cognitive Ability Predict Greater Prejudice?”. This reviews a bunch of research and, defying Betteridge, says that the consensus is that lower cognitive ability predicts greater prejudice. This paper says that less intelligent people are more prejudiced and authoritarian; it says nothing about their economic beliefs.
  • Carl (2015), “Cognitive ability and political beliefs in the United States”. This paper thinks that intelligence is correlated with fiscal conservatism, but the trend reverses at high IQs. It also finds that intelligence is correlated with social liberalism.
  • Carl (2014), “Cognitive ability and party identity in the United States”. This paper finds that Republican voters are a few IQ points smarter than Democrat voters. The author says “These results are consistent with Carl’s (2014) hypothesis that higher intelligence among classically liberal Republicans compensates for lower intelligence among socially conservative Republicans.”
  • Duarte et al (2015), “Political diversity will improve social psychological science”. This paper, co-written by Haidt, is mostly about other things, but talks about intelligence differences between liberals and conservatives as a hypothesis for why conservatives are underrepresented in academia. The paper refers to some of the other papers I’ve looked at here and treats them as reasonable; coming from critics of political bias in social psychology, this caused a mild positive update for my opinion on the quality of the research.

How legit do I think this is overall? This is social psychology research, so we should always be pretty suspicious that it’s actually just totally wrong for some reason too fundamental for us to notice, and we should treat all results as provisional until they’re replicated.

I guess one point in the favor of these studies is that they doesn’t totally play into the worldview of the liberal academics running them. Their data makes more sense to me than it does to them, I think. This seems true of other research on similar topics too: research on political attitudes seems to often have results that conflict with the biases of the researchers–eg that smarter people are more economically liberal.

Overall, I think that the findings of these researchers seem plausible.