Then, the two groups are asked to do a second, seemingly unrelated task—basically a kind of logic puzzle where they have to trace out a complicated geometric pattern without raising their pencil. Unbeknownst to them, the puzzle can’t be solved. The scientists are curious how long they’ll persist at a difficult task. So the cookie-eaters try again and again, for an average of 19 minutes, before they give up. But the radish-eaters—they only last an average of 8 minutes. What gives?
The answer may surprise you: They ran out of self-control. Psychologists have discovered that self-control is an exhaustible resource. And I don’t mean self-control only in the sense of turning down cookies or alcohol, I mean a broader sense of self-supervision—any time you’re paying close attention to your actions, like when you’re having a tough conversation or trying to stay focused on a paper you’re writing. This helps to explain why, after a long hard day at the office, we’re more likely to snap at our spouses or have one drink too many—we’ve depleted our self-control.
And here’s why this matters for change: In almost all change situations, you’re substituting new, unfamiliar behaviors for old, comfortable ones, and that burns self-control. Let’s say I present a new morning routine to you that specifies how you’ll shower and brush your teeth. You’ll understand it and you might even agree with my process. But to pull it off, you’ll have to supervise yourself very carefully. Every fiber of your being will want to go back to the old way of doing things. Inevitably, you’ll slip. And if I were uncharitable, I’d see you going back to the old way and I’d say, You’re so lazy. Why can’t you just change?