What IQ Tests Really Measure

Students taking a test

Kids who score highly on IQ tests will, on average, do better in conventional measures of success. Is that because they are more intelligent?

Is it an example of what Malcolm Gladwell so eloquently points out in Outliers — where people showing even a trace advantage over others are constantly reinforced as being smart, given more opportunities, etc.

Or is something else at play?

The controversial 1990’s book “The Bell Curve” contended that genetic differences were one reason certain ethnic groups scored lower. In 2009, another book on the subject, “Intelligence and How to Get It” by Richard Nisbett, a psychologist at the University of Michigan, Ann Arbor, argued that differences in IQ scores largely disappear when researchers control for social and economic factors.

New research concludes that IQ scores are partly a measure of how motivated a child is to do well on the test. “While subjects taking such tests are usually instructed to try as hard as they can, previous research has shown that not everyone makes the maximum effort. A number of studies have found that subjects who are promised monetary rewards for doing well on IQ and other cognitive tests score significantly higher.” Incentives increase IQ scores — but do they increase native intelligence or only our motivation?

This is where psychology professor Carol Dweck enters the picture. She argues the secret to raising smart kids is not to tell your kids they are smart because that impacts motivation. According to Dweck, people’s self-theories about intelligence have a profound influence on their motivation to learn. More than three decades of research shows that a focus on effort—not on intelligence or ability—is key to success in school and in life. If you know a Type-A parent, chances are they have a well-thumbed copy of Dweck’s book Mindset: the new psychology of success on their night-stand beside Amy Chua’s Why Chinese Mothers are Superior book. 

A brief summary of Dweck, as I understand it, goes something like this: What people think about their own intelligence has wide-ranging consequences. If you think you’re naturally smart, you won’t work hard (motivation). If you think you’re smart because you work hard, you’ll continue to work hard. Thinking that intelligence is unchangeable (you’re naturally smart and don’t have to work hard) means that you avoid difficult challenges because failure might cause a loss in the appearance of intelligence.

Dweck says “One very common thing is that often very brilliant children stop working because they’re praised so often that it’s what they want to live as—brilliant—not as someone who ever makes mistakes.” This she says “really stunts their motivation. Parents and teachers say they now understand how to prevent that—how to work with low-achieving students to motivate them and high-achieving students to maximise their efforts.” The point is to praise children’s efforts, not their intelligence.

Bottom line: Both intelligence and personality matter. I’m not sure if intelligence can be changed but you can certainly reach your potential through effort.

H/T Marginal Revolution for getting me started.  The Farnam Street Blog serves candy for your brain.