In his classic 1923 essay, "Intelligence as the Tests Test It", Edwin Boring wrote "Intelligence is what the tests test." Almost a century of research later, we know that this definition is far too narrow. As long as a test is sufficiently cognitively complex and taps into enough diverse content, you can get a rough snapshot of a person's general cognitive ability—and general cognitive ability predicts a wide range of important outcomes in life, including academic achievement, occupational performance, health and longevity.
But what about happiness? Prior studies have been mixed about this, with some studies showing no relationship between individual IQ and happiness, and other studies showing that those in the lowest IQ range report the lowest levels of happiness compared to those in the highest IQ group. In one study, however, the unhappiness of the lowest IQ range was reduced by 50 percent once income and mental health issues were taken into account. The authors concluded that "interventions that target modifiable variables such as income (e.g., through enhancing education and employment opportunities) and neurotic symptoms (e.g., through better detection of mental health problems) may improve levels of happiness in the lower IQ groups."
One major limitation of these prior studies, however, is that they all rely on a single measure of happiness, notably life satisfaction. Modern day researchers now have measures to assess a much wider array of indicators of well-being, including autonomy, personal growth, positive relationships, self-acceptance, mastery, and purpose and meaning in life.
Enter a new study conducted by Ana Dimitrijevic and colleagues, in which they attempted to assess the relationship between multiple indicators of intelligence and multiple indicators of well-being. They relied on the following definition of intelligence: "the ability to understand complex ideas, to adapt effectively to the environment, to learn from experience, to engage in various forms of reasoning, and to overcome obstacles by taking thought." This definition covers several more specific notions of intelligence, such as emotional intelligence.
The researchers administered a battery of intelligence and well-being measures to 288 adults employed within various departments of a large dairy production company in Belgrade. What did they find?
Intelligence and Well-Being
The researchers found that both IQ and emotional intelligence were independently correlated with well-being.* IQ was positively correlated with personal relationships, self-acceptance, personal growth, mastery and purpose in life.** Emotional intelligence was correlated with the same well-being measures, but was additionally related to a sense of autonomy in life.
Zooming in on the IQ test, the most predictive subscale for well-being was a measure of non-verbal fluid reasoning, which requires pattern detection and abstract reasoning (constructing generalizable principles from minimal information). Some people argue that this form of reasoning is strongly related to general intelligence.
Once socioeconomic status (SES) was taken into account (reflecting higher education and income), however, there was no relationship between IQ and well-being. According to the researchers, this suggests that IQ leads "to greater contentment with oneself and life primarily by enabling one to acquire the social status and financial means which ensure better opportunities and quality of life." Of course, this does not mean that IQ is simply a measure of SES; IQ was positively correlated with well-being. However, it does suggest that the extent to which IQ is related to happiness depends to a large extent on the opportunities (e.g., financial, educational) you have to utilize your IQ.
What about emotional intelligence? The emotional intelligence tests that were most predictive of well-being were the two higher, more "strategic" branches—Understanding and Managing Emotions. The person who scores higher in these facets of emotional intelligence are better able to comprehend the emotional signals coming from others, and to regulate and manage their own and others' emotions so as to further their own and others' personal and social goals.
Emotional intelligence had a direct effect on well-being, and this association remained strong even after controlling for SES. What's more, of the two measures of intelligence—IQ and emotional intelligence—emotional intelligence was the strongest predictor of well-being, outweighing not only IQ, but also a person's SES and age. This finding suggests that emotional intelligence—particularly the capacity to manage one's emotions toward optimal personal goal attainment—is a form of intelligence that can help people live a more fulfilled life regardless of their economic circumstances.
Why Is Intelligence Associated with Well-Being?
I think intelligence matters for a fulfilling life for a number of reasons. For one, a higher IQ is a gateway to better education. Those with higher IQ scores are much more likely to score well on standardized tests of achievement, and academic performance is often the first hurdle necessary to continue up the ladder of occupational opportunities.
Also relevant here is the association between IQ and openness to experience. Those with a higher IQ tend to score higher in a number of facets of openness to experience, including intellectual engagement, intellectual creativity, introspection, ingenuity, intellectual depth and imagination. This tendency for deeper cognitive processing is critical for dealing with a lot of life's up and downs. While trauma is inevitable in life, research shows that we can grow from our traumas if we have a healthy form of rumination in which we reflect on the deeper meaning of the event and can use that cognitive processing to perceive greater opportunities for ourselves and others.
Regarding emotional intelligence, since having a fulfilling life often requires accomplishing the goals you have set out for yourself, it makes sense that being able to manage your emotions in the service of a larger goal will be associated with well-being and self-actualization.
Perhaps the most important analysis will turn out to be how IQ and emotional intelligence interact. There is some evidence that in certain contexts, emotional intelligence can amplify the effectiveness of a high IQ, and high emotional intelligence can even compensate for a lower IQ. Future research should definitely look more closely at the interaction between these two important aspects of human intelligence.
Of course, it's possible that the findings operate in reverse causation, and being happier increases intellectual skills. Most likely, both directions are at play in the correlations found in the study. Clearly more research will need to look at the association between intelligence and well-being over time.
At any rate, I'm pleased to see that this line of research is being conducted. I believe a great responsibility we have as a society is to ensure that all people—regardless of their IQ score—are able to self-actualize and lead a life of self-acceptance, autonomy, meaning and positive social relationships.
* It should be noted that IQ and emotional intelligence were moderately correlated with each other. This suggests that both tests are tapping into a common set of processes (e.g., executive functioning, working memory, etc.), even though IQ and emotional intelligence also involve a partially different set of skills.
** The researchers provided this more detailed analysis of well-being upon my request.