Intelligence predicts charitable giving and voting in massive Swedish study

People with higher cognitive abilities are more likely to engage in actions that benefit society, such as donating to charity, voting in elections, and buying environmentally friendly vehicles. These findings suggest that general intelligence plays a direct role in driving cooperative, socially minded actions. The research was published in The Economic Journal.

Humans are uniquely inclined to cooperate with strangers and contribute to public goods. Evolutionary biologists and economists often categorize these actions as prosocial behaviors. Finding a rational explanation for why humans evolved into such cooperative animals has long challenged researchers across multiple disciplines.

One proposed explanation centers on human intelligence. Some theorists suggest that cognitive ability improves logical reasoning and the capacity to understand the perspectives of others. These mental skills naturally foster ethical reasoning, which can ultimately lead to a sense of altruism.

Other researchers propose that intelligent individuals often achieve higher incomes and better social standing. This wealth could lower the personal financial cost of giving away money or time. Up until now, evidence linking intelligence to prosocial behavior has mostly come from brief laboratory games or surveys where people report their own habits.

To find concrete answers, economists Mikael Elinder and Oscar Erixson analyzed a massive set of Swedish administrative records. They wanted to see if objective measures of intelligence predicted documented, real world prosocial behaviors. The researchers focused on three specific actions: charitable giving, voting, and the ownership of environmentally friendly cars.

The researchers first analyzed data from over 1.2 million Swedish men and about 3,000 Swedish women. All of these individuals took a standardized cognitive test during their military enlistment process between 1969 and 1997. This exam evaluated logical, verbal, spatial, and technical abilities on a nine point scale.

The researchers then matched these historical test scores with modern government records. They looked at tax registries from 2012 to 2015 to track charitable donations. Because Swedish charities automatically report donations to the government for tax purposes, the data minimizes biases related to a person’s financial literacy or their willingness to fill out tax forms.

To measure political participation, the researchers examined electoral rolls for the 2009 European Parliament election. By using validated voter turnout data, the team avoided the common problem of people lying about their voting habits in surveys. Finally, they consulted a national vehicle database to identify households that owned cars powered by electricity, ethanol, or natural gas.

Individuals with higher cognitive scores were much more likely to engage in all three prosocial behaviors. Men with the highest cognitive scores were more than five times as likely to donate to charity compared to men with the lowest scores. A one standard deviation increase in intelligence matched a 40 percent relative increase in the likelihood of charitable giving.

The same bump in test scores corresponded to a 31 percent increase in voting. It also matched a 14 percent increase in eco-friendly car ownership. The data from the female participants revealed very similar positive trends for voting and charity, showing that the effect was not limited to men.

When looking at specific types of intelligence, the researchers noticed that logical and verbal reasoning were the strongest predictors of prosocial action. These two traits are widely considered the best indicators of general fluid intelligence. Fluid intelligence is the ability to think abstractly and solve novel problems.

Observing a link in the general population does not prove that intelligence directly causes prosocial behavior. People with high cognitive scores often grow up in wealthy families or specific neighborhoods that might actively encourage civic duties. To account for these shared background variables, Elinder and Erixson conducted a second analysis using a large sample of 5,786 twin pairs.

Because twins typically share the same upbringing, home environment, and a large portion of their genetics, comparing siblings helps account for many confounding factors and better isolate the effect of intelligence. The researchers looked at twin pairs where one sibling scored higher on the enlistment cognitive test than the other. They also controlled for general personality traits evaluated during the military interviews, such as emotional stability and sociality.

The researchers found that the smarter twin was consistently more likely to vote and donate to charity. The associations decreased in size by about half compared to the massive population sample. A one standard deviation increase in cognitive ability among twins matched a 26 percent increase in charitable giving and a 13 percent increase in voting.

The link to eco-friendly car ownership also dropped to a 13 percent increase. This twin based approach indicates that unobserved family factors account for some of the population wide trend. However, those family factors do not entirely explain the connection between cognitive ability and prosocial habits.

Elinder and Erixson then ran a third analysis to test specific lifestyle variables that might bridge the gap between intelligence and behavior. A person’s intelligence influences their life trajectory, which could in turn dictate their civic engagement. The researchers factored in differences in education, total income, marriage status, the presence of children, and the municipality of residence.

Education explained a noticeable portion of the link between cognitive scores and civic habits. This aligns with the idea that schools help transmit prosocial values or develop a person’s ethical awareness. Individuals who spend more years in the educational system often learn to prioritize community well being.

Income did not act as a major mediator. Smarter individuals were not simply donating or buying eco-friendly cars just because they had more money to spare. When accounting for all these lifestyle variables, the direct mathematical link between intelligence and owning an eco-friendly car was not statistically significant.

However, the direct connection to voting and charitable giving held firm even after adjusting for education and income. The researchers interpreted this as evidence of a profound, direct tie between intelligence and certain types of cooperation. General intelligence appears to influence these behaviors independently of a person’s life circumstances.

Finally, the researchers looked at survey responses from a separate sample of about 600 men. These men had previously reported their own feelings of altruism on a numerical scale, along with their patience and risk preferences. The researchers matched these survey answers to the men’s military enlistment cognitive scores.

Individuals with higher cognitive abilities expressed a higher degree of personal altruism, with a one standard deviation increase in cognitive ability associated with a 0.16 standard deviation increase in self-reported altruism. This self reported data is in line with the behavioral records found in the national registries. While the survey results cannot firmly distinguish between different mechanisms, they are consistent with the theory that cognitive ability influences prosocial behavior through ethical reasoning and altruism.

While the twin analysis helps control for many background factors, the findings do not guarantee a strict cause and effect relationship in every scenario. The study relies heavily on data from Swedish men born between 1951 and 1979. The exact percentages might vary across different cultures, age groups, or time periods.

Additionally, the research defines prosocial behavior through three specific financial and political actions. People with lower cognitive scores might be equally cooperative in ways that do not show up in tax or vehicle registries, such as volunteering or helping neighbors physically. Future research will need to explore how other cognitive functions, like empathy and the ability to read emotions, interact with general intelligence to shape human cooperation.

The study, “An inquiry into the relationship between intelligence and prosocial behaviour: Evidence from Swedish population registers,” was authored by Mikael Elinder and Oscar Erixson.