Politics and IQ: Are liberals smarter than conservatives?

The question of whether political leanings are connected to intelligence is a long-standing and often contentious topic. While many assume their ideological opponents are simply less intelligent, scientific research paints a far more nuanced picture.

A series of studies published over the last decade reveals that the answer depends heavily on how “intelligence” is measured and which specific political beliefs are examined. The findings show that while lower cognitive ability is consistently associated with social conservatism, the relationship with economic conservatism is more complicated, with recent research pointing to the unique role of verbal skills and genetic factors.

The Initial Puzzle: A Republican Advantage in Verbal Intelligence

Contrary to a common assumption that intelligence aligns with liberalism, a 2014 study published in the journal Intelligence presented a puzzling finding. Previous research had consistently shown that people with higher intelligence tend to be more socially liberal and less religious, which would suggest Democrats might have a cognitive edge. This study sought to test that expectation directly.

The research, led by Noah Carl, analyzed data from the General Social Survey (GSS), a large, nationally representative survey of American adults. Intelligence was measured using a 10-word vocabulary test, which serves as a proxy for verbal intelligence. Political affiliation was determined by how people identified themselves—as a “strong Democrat,” “strong Republican,” Independent, and so on—as well as their voting history in presidential elections.

The results were unexpected. Before accounting for other factors, individuals who identified as Republican had slightly higher average verbal intelligence scores than those who identified as Democrat, with the advantage ranging from 2 to 5 IQ points. The gap was largest when comparing “strong Republicans” to “strong Democrats.” A similar, smaller Republican advantage of about 2 IQ points was found among voters. However, when the researchers statistically controlled for socioeconomic characteristics like education, income, race, and marital status, the Republican advantage almost entirely disappeared or, in some cases, even reversed.

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To understand this, the study also examined the link between verbal intelligence and specific policy beliefs. It found that higher verbal intelligence was associated with more socially liberal views, such as support for abortion access and LGBTQ+ rights. At the same time, higher verbal intelligence was also linked to more “economically liberal” views, a term used in the classical sense to mean support for free-market principles and less government intervention. This is what is more commonly known today as economic conservatism. The study suggested that the higher intelligence of economically conservative Republicans might compensate for the potentially lower intelligence of socially conservative ones, leading to the small overall Republican advantage.

Confirming the Finding with Broader Cognitive Measures

To ensure these findings were not a fluke of using a single vocabulary test, the same researcher published a follow-up study in Intelligence later in 2014. This second study built directly on the first by using the same GSS dataset but expanding the analysis to include three additional measures of cognitive ability: a test of probability knowledge, a test of verbal reasoning, and an interviewer’s assessment of how well the respondent understood the survey questions.

The methodology was similar to the first study, comparing the average scores on these cognitive tests between self-identified Republicans and Democrats. It also investigated how much of the relationship could be explained by socioeconomic factors like education and income.

The findings confirmed the results of the initial paper. On all three new cognitive measures, Republicans showed a small but statistically significant advantage, with differences ranging from approximately 1 to 4 IQ points. Again, the advantage was largest when comparing the most strongly identified partisans. The analysis also revealed that a significant portion—often more than half—of this relationship was accounted for by socioeconomic position.

The study suggested a chain of influence: individuals with higher cognitive ability tend to achieve higher education and income, and people with these higher socioeconomic profiles are more likely to identify as Republican. This confirmed the initial finding was robust across different types of cognitive tests but also reinforced that socioeconomic factors were deeply intertwined with the results.

The Broader View: Lower Intelligence and Social Conservatism

While the Carl studies pointed to a small Republican advantage, they stood in contrast to a wider body of research. A comprehensive meta-analysis published in the European Journal of Personality in 2015 synthesized decades of research to clarify the broader relationship between cognitive ability, right-wing ideological attitudes, and prejudice. A meta-analysis is a “study of studies” that combines the results of many different papers to find an overall effect.

Researchers led by Emma Onraet compiled data from 67 studies focusing on right-wing attitudes and 23 studies focusing on prejudice, totaling over 84,000 and 27,000 participants, respectively. They examined different types of ideology, such as authoritarianism and social conservatism, and different types of cognitive tests. It is important to note this analysis focused on sociocultural attitudes, not economic ones.

The meta-analysis revealed a consistent and noticeable trend: on average, people with lower cognitive ability scores were reliably more likely to endorse right-wing social attitudes and hold prejudiced views. The overall strength of this connection was considered moderate—not a perfect one-to-one relationship, but a clear pattern observed across dozens of different studies.

This link was even more pronounced for specific beliefs, with a stronger connection found between lower cognitive ability and both authoritarianism and ethnocentrism (prejudice against other ethnic groups).

The study also gave an early hint that the a person’s specific type of intelligence might matter, noting that verbal skills in particular seemed more strongly related to ideology than other cognitive abilities. By focusing on social attitudes, this large-scale review helped sharpen a distinction that would become central to later research: the link between intelligence and political beliefs appears to operate differently for social issues compared to economic ones.

Pinpointing the Key Skill: The Unique Role of Verbal Ability

Building on the hints from prior work, a 2017 study in Intelligence sought to determine which specific kind of intelligence—verbal or non-verbal—is the main driver of political ideology. It is one thing to say “intelligence” is linked to liberalism, but another to identify the precise cognitive skill involved.

The study, led by Steven G. Ludeke, analyzed data from two separate American community samples. Both samples included measures of politics as well as tests for both verbal intelligence (e.g., vocabulary, analogies) and non-verbal intelligence (e.g., block design, matrix reasoning). A key difference was that one sample completed a self-administered test at home, while the other was assessed in a lab by a trained researcher using a standard IQ inventory. The researchers then used statistical models to see which type of ability best predicted scores on a political liberalism scale.

The results showed that while higher general intelligence was associated with more liberal views, this link was driven almost exclusively by verbal ability. In models that included both verbal and non-verbal intelligence as predictors, non-verbal ability had no independent relationship with political ideology.

Verbal ability, however, remained a strong predictor. In fact, the entire association between general intelligence and liberal beliefs was accounted for by a person’s verbal skills. The study also found that the relationship was significantly stronger in the sample that used the professionally-administered, in-person IQ test, suggesting that brief, self-administered tests may underestimate the true strength of the connection.

Resolving the Paradox: A Tug-of-War in Economic Beliefs

The research so far presented a paradox: lower intelligence seemed linked to social conservatism, but some studies suggested a positive link with economic conservatism. A 2021 study published in the Personality and Social Psychology Bulletin tackled this inconsistency head-on by focusing solely on economic ideology.

This research, led by Alexander Jedinger and Axel Burger, involved two parts. First, they conducted a meta-analysis of 19 articles to find the average relationship between cognitive ability and economic conservatism. Second, they analyzed data from the 2016 American National Election Study (ANES) to test competing theories about *why* this link exists.

The meta-analysis of existing research found a small but significant positive average correlation between higher cognitive ability and greater economic conservatism. However, the results were extremely varied across studies, with some showing positive links, some negative, and some no link at all. The relationship was stronger in studies that used specific policy questions (operational ideology) rather than just asking people to label themselves (symbolic ideology).

The second part of the study offered an explanation for this messiness. Analyzing the ANES data, the researchers found evidence for two opposing “countervailing” pathways that link intelligence to economic attitudes. First, a “self-interest” path showed that higher cognitive ability leads to higher income, which in turn predicts more economic conservatism.

Second, an “epistemic needs” path showed that higher cognitive ability is associated with a lower need for certainty and closure, which in turn predicts less economic conservatism. These two mechanisms act like a tug-of-war, pulling people in opposite directions. This finding helps explain why the overall correlation is so weak and why different studies have produced conflicting results.

The Latest Evidence: Genetics, Family, and the Primacy of Verbal Skills

The most recent research, published in Intelligence in 2024, has pushed the inquiry into new territory by incorporating genetics and using powerful family-based study designs to control for environmental influences. A pair of studies led by Tobias Edwards has provided some of the strongest evidence to date on the nature of the intelligence-ideology link.

One study used data from the Sibling Interaction and Behavior Study (SIBS), which includes both biological and adopted siblings. This design allows researchers to separate the effects of genetics from shared family upbringing. Intelligence was measured with standard IQ tests and also with “polygenic scores,” which are estimates of a person’s genetic predisposition for a trait based on their DNA.

The study found that even within the same family, the sibling with a higher IQ or a higher polygenic score for intelligence was more likely to hold liberal political beliefs. This suggests that the connection is not just a product of one’s environment but may be partially rooted in the genetic variations that influence cognitive ability.

A second study by the same authors used data from two large Minnesota-based family studies to conduct a comprehensive test of the verbal versus non-verbal intelligence question. The researchers looked at a wide range of outcomes, including voter turnout, civic engagement, religiosity, and different facets of political ideology.

They found that verbal IQ was consistently about twice as strong a predictor of these socio-political attitudes and behaviors as performance (non-verbal) IQ. This powerful effect of verbal ability held true even when comparing siblings raised in the same house and after accounting for education levels, confirming and extending the 2017 findings from Ludeke and colleagues.

Conclusion

So, are liberals smarter than conservatives? The science shows that this is the wrong question to ask. The answer is far from a simple “yes” or “no” and has become clearer over time. Research suggests that people with lower cognitive abilities are more likely to endorse socially conservative and authoritarian views. However, the link with economic conservatism is a complicated tug-of-war between self-interest and epistemic needs, resulting in a very weak and inconsistent relationship.

Most importantly, recent studies have revealed that it is not general intelligence but specifically *verbal intelligence*—the ability to understand and reason with words—that most strongly predicts liberal-leaning views, civic engagement, and lower traditionalism. This connection appears to have a genetic component and is not simply a result of education or upbringing.

Researchers caution, however, that these are statistical averages and that intelligence is only one of many factors influencing a person’s beliefs. As study author Tobias Edwards previously told PsyPost, “It is very tempting to make inferences to the veracity of an ideology based on the intelligence of its supporters,. But this would be a mistake. There have been extraordinarily intelligent people on both the left and right… there is no reason why we must presume one ideology to be more intelligent than another, even if smart people seem more likely to align with one belief or another.”

Finally, it is essential to remember that these findings exist within a specific moment in time, because the beliefs that define “liberal” and “conservative” are not static. The Republican Party of today, for instance, holds different core positions on issues like trade and foreign policy than the party of Dwight D. Eisenhower. As party platforms and ideological movements evolve, the cognitive traits of the people they attract may change as well.

The research itself points to this fluidity. In one study, Edwards noted that his recent data showed higher intelligence was linked to less fiscal conservatism, a reversal of the trend found in older data.

“This surprise highlights an important point; there is no law saying that intelligent people must always be supportive of particular beliefs or ideologies. The way our intelligence affects our beliefs is likely dependent upon our environment and culture. Looking back across history, we can see intelligent individuals have been attracted to all sorts of different and often contradictory ideas.”