A new large-scale study shows that people with higher cognitive abilities are more likely to behave in ways that benefit society. In this study, higher intelligence scores are associated with higher voter turnout, philanthropy, and purchasing greener cars. The findings provide a rare real-world perspective on how general mental abilities relate to cooperative behavior. The study was published in the Economic Journal.
Humans are very cooperative animals. We regularly share resources with strangers and contribute to the public good. Public goods are shared resources that benefit everyone, including those who do not pay for or maintain them. Finding a rational explanation for human cooperation has long puzzled evolutionary biologists.
Some previous academic theories have suggested that generous behavior may simply be an optimization error. Under this idea, people act generously because they miscalculate the personal costs of their actions. Other theorists have proposed that greater intelligence improves the capacity for ethical reasoning. If your brain is well-developed, you may be better able to understand other people’s points of view.
If ethical reasoning theory were true, higher cognitive abilities would naturally lead to stronger principles of altruism. People will want to act in a way that is consistent with their internal moral compass. Violation of these principles can result in psychological discomfort. This psychological discomfort is known as cognitive dissonance.
Economists Mikael Elinder and Oskar Eriksson from Uppsala University in Sweden wanted to investigate whether intelligence directly predicts prosocial behavior. Prosocial behavior includes any behavior aimed at helping others or society as a whole. Past research on this topic often relied on self-report surveys or small-scale laboratory games.
These traditional research methods have known limitations. People often exaggerate their good deeds in surveys to look good in the eyes of researchers. In a laboratory setting, the artificial nature of the game may not reflect how people behave with their money. To get around these problems, economists turned to objective government records.
The researchers analyzed a large sample of 1.2 million individuals using Sweden’s administrative register. Most of the subjects were men born between 1951 and 1979, who took mandatory psychological and cognitive tests during their military service in their late teens. The researchers also looked at a large sample of about 3,000 women who volunteered to enlist.
Military cognitive tests measured logical, verbal, spatial, and technical abilities. These scores are highly predictive of an individual’s intellectual ability throughout adulthood. Economists then related these historical test scores to three objective measures of adult behavior. A verified government database tracked subjects decades after their initial enlistment.
The researchers used Internal Revenue Service records to define charitable donations. During the specific study period, the Swedish government offered tax breaks for donations to approved humanitarian charities. Tax authorities automatically recorded gifts over a certain amount. This automatic recording eliminates the need for donors to proactively submit complex tax forms.
To track citizen participation, researchers looked at valid turnout records for European Parliament elections. Voting takes time and effort, but elections are rarely decided by individual votes. Political scientists often consider modern voting to be a civic duty that strengthens democratic institutions. Finally, the researchers looked at national vehicle registries to see who owned cars that ran on electricity or alternative fuels such as ethanol.
Researchers found strong positive associations between cognitive test scores and all three behaviors. For men, a one standard deviation increase in cognitive ability was associated with a 40% increase in the likelihood of making a charitable donation. A similar increase in cognitive ability was associated with a 31 percent increase in the likelihood of voting. It was also associated with a 14% greater likelihood of owning a green car.
Female participants showed a very similar pattern. Higher test scores predicted greater activity in charitable giving and voting. The only difference is that the data for women yielded a statistically insignificant result for green car ownership.
Researchers found that scores on the logical and verbal portions of military tests were the strongest predictors of generous behavior. Psychologists consider these specific sections to be the best proxy for general intelligence. General intelligence refers to the comprehensive ability to reason, solve problems, and adapt to new situations.
Finding a statistical association between intelligence and good behavior does not establish a direct cause. Smart people often grow up in wealthy families and in better neighborhoods. These environments may independently promote prosocial habits. Parents may have inherited expectations for philanthropy, or ordered neighborhoods may simply provide better conditions for brain development.
To account for these overlapping background factors, the researchers isolated a large group of 5,786 male twin pairs from within their data. Twins usually share the same upbringing, schooling, and genetic background. By comparing one twin to another, researchers can rule out the effects of a shared family environment.
When the researchers compared the twins, the mathematical estimate was lower, but still positive. Twins who scored higher on cognitive tests were more likely to vote consistently and donate to charity than their younger siblings. The association with green car ownership also remained positive, although the difference between siblings was not statistically significant.
This specific comparison suggests that unmeasured childhood environment explains about half of the initial association. Yet, once these background effects are subtracted, a robust mathematical relationship remains. The researchers interpret this as evidence of a real, direct link between intelligence and cooperative behavior.
Elinder and Erickson also investigated whether other adult outcomes could explain the association. They adjusted their statistical models for income, education level, marital status, and municipality of residence. Higher education partially explained why smart people behaved more generously. Schools teach civics duties and often explicitly expose students to broader social issues.
Surprisingly, income in adulthood alone did not explain this relationship. One might think that smarter people usually earn more, making it easier to give gifts to charity or buy expensive cars. The data did not support this particular idea. The link between intelligence and prosocial behavior was strong, regardless of an individual’s personal wealth.
The economists also looked at a smaller subset of participants who responded to the latest survey to test their administrative findings. They found that people with higher cognitive scores explicitly described themselves as more altruistic. Altruism is the selfish desire to help others without expecting anything in return.
The researchers note several caveats regarding their conclusions. The study mainly focused on monetary donations, voting, and car purchases. These individual actions do not involve any kind of goodwill. Less intelligent people may simply express their cooperative tendencies in other unmeasured ways, such as volunteering in their local community or manually helping their neighbors.
Future research should investigate precisely how related psychological traits like empathy interact with general intelligence. Understanding these mental mechanisms could help policy makers design better public awareness campaigns. If cognitive abilities determine how people respond to public dilemmas like climate change, governments may need to tailor interventions to different segments of the population. Environmental campaigns may ultimately need to rely not on abstract moral arguments alone, but on simple incentives for action.
The study, “Investigating the relationship between intelligence and prosocial behavior: Evidence from the Swedish Population Register,” was authored by Mikael Elinder and Oskar Eriksson.
