Scott Barry Kaufman in Scientific American:
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% 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 limitations 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.