Intelligence tests used to make Bob Sternberg a little sick. “The school psychologist would come into the room and give us these group IQ tests. And I would freeze up, especially when I heard other kids turning the page and I was still on the first or second problem.” As a result, Sternberg routinely bombed his IQ tests. But his fourth-grade teacher didn’t believe the numbers, and she con- vinced Sternberg not to believe them either.
His teacher was right. Sternberg grew up to be an insightful, influential researcher and—ironically—a world-renowned expert on intelligence, first as a psy- chology professor at Yale University and now as the dean of arts and sciences at Tufts University. Throughout his career, he has explored the question of what intelli- gence is, where it comes from, and how people can get more of it. But Sternberg’s own trajectory reminds us that the correlation between IQ scores and life success is far from 1.00.
IQ tests are designed to measure intelligence, but do they? For that matter, what is intelligence? More than a decade ago, 52 experts offered a multifaceted definition of this term: “the ability to reason, plan, solve problems, think abstractly, compre- hend complex ideas, learn quickly and learn from experience”. This is a complex definition, but we may need further complications, because, in this, we’ll consider proposals that would expand this definition by taking into account important talents excluded from the experts’ conceptualization. We’ll also look at proposals that would subdivide the definition, so that we end up speak- ing about different types, and different aspects, of intelligence.
These points should make it clear that, after a century of research in this domain, there’s still room for debate about what intelligence is and how it should be defined. Despite these complications, we’ll see that in the last century, researchers have made enormous progress in identifying the intellectual and motivational components that contribute to IQ scores, and also have learned an enormous amount about the roots of these components. To understand this progress, we need some historical context: Researchers first set out to measure intelligence 100 years ago, and much of what we’ve learned—and many of the questions that remain—can be traced directly to these early efforts. Let’s begin our story, therefore, at the beginning, in France in the opening years of the 20th century.