If you have a student, colleague, or friend who’s always late and leaves you waiting, here’s a technique that may change their behavior. The day before your next scheduled meeting together, just ask, “Will you be late tomorrow?”

Most people can’t bring themselves to answer yes to that question. But just considering the question at all makes them examine what they’re doing and consider what kind of behavior they want to model. Psychologists call this “self-persuasion,” and it’s surprisingly effective.

We’re more likely to persuade ourselves to change than we are to be persuaded.