The Data Detective: Ten Easy Rules to Make Sense of Statistics

by Tim Harford

A bat and ball cost $1.10, and the bat costs a dollar more than the ball. How much does the ball cost? and: A lake contains a patch of lily pads which doubles in size each day. If it takes 48 days for the patch to cover the entire lake, how long would it take for the patch to cover half of the lake?[*] Many people get the answers to these questions wrong the first time they hear them, but what’s required to reach the correct solution isn’t intelligence or mathematical training, but pausing for a moment to double-check your gut reaction. Shane Frederick points out that noticing your initial error is usually all that’s necessary to solve the problem.[24] The cognitive reflection questions invite us to leap to the wrong conclusion without thinking. But so, too, do inflammatory memes or tub-thumping speeches. That’s why we need to be calm. And that is also why so much persuasion is designed to arouse us—our lust, our desire, our sympathy, or our anger. When was the last time Donald Trump, or for that matter Greenpeace, tweeted something designed to make you pause in calm reflection? Today’s persuaders don’t want you to stop and think. They want you to hurry up and feel. Don’t be rushed.