Her most famous study, conducted in twelve different New York City schools along with Claudia Mueller, involved giving more than 400 fifth graders a relatively easy test consisting of nonverbal puzzles. After the children finished the test, the researchers told the students their score, and provided them with a single line of praise. Half of the kids were praised for their intelligence. “You must be smart at this,” the researcher said. The other students were praised for their effort: “You must have worked really hard.”
The students were then allowed to choose between two different subsequent tests. The first choice was described as a more difficult set of puzzles, but the kids were told that they’d learn a lot from attempting it. The other option was an easy test, similar to the test they’d just taken.
When Dweck was designing the experiment, she expected the different forms of praise to have a rather modest effect. After all, it was just one sentence. But it soon became clear that the type of compliment given to the fifth graders dramatically affected their choice of tests. When kids were praised for their effort, nearly 90 percent chose the harder set of puzzles. However, when kids were praised for their intelligence, most of them went for the easier test. What explains this difference? According to Dweck, praising kids for intelligence encourages them to “look” smart, which means that they shouldn’t risk making a mistake.