Credit: AP Photo / Dave Martin

Note: This piece was updated on March 22nd, 2019.

Have you ever taken an IQ test? Think about the results. Did you do well? You might have gotten a high score, but, often, intelligence doesn’t have anything to do with rationality. There is a marked difference between the two, although we often conflate them. We talk with York University associate professor Maggie Toplak and Boston University professor Carey Morewedge about why even smart people do irrational things.

Three Takeaways:

• Some of us are bad at making rational decisions because we’re “cognitive misers.” We don’t spend as much time thinking about decisions as we should. Of course, being a cognitive miser can be helpful (who wants to waste time choosing shampoo?) But saving time by not thinking about your 401(k) options? Not a great move.
• Socrates had it right when he said, “The only thing I know is that I know nothing.” We tend to make more irrational decisions when we’re overconfident.
• Believe it or not, you can become more rational if you practice. But it’s not that easy. We’re surrounded by biases that constantly drag down our rational thinking. That’s why, Morewedge says, employers often make poor choices when hiring.

More Reading:

• Want to know more about the difference between rationality and intelligence? The New York Times breaks down the history behind this research.
• Intelligence is great, but rational people might lead better lives, according to this study.
• Toplak, along with her co-researchers, Keith Stanovich and Richard West, wrote the Rationality Quotient: Toward A Test of Rational Thinking, where they outline a test for gauging rational thinking. The Comprehensive Assessment of Rational Thinking, or CART, asks users to complete a series of questions about theoretical scenarios regarding everything from frozen strawberries to teen smoking. See how rational you are and we’ll announce the test results on Facebook in the near future: