To persuade someone to do (or not to do) something, suggest that she consider a possible negative outcome. Expecting regret can bring compliance.

Pretend you sell car insurance, and you urge a customer to buy a policy. It’s possible he will decline, even if he doesn’t have one already. He might not want to spend the money, or perhaps he has a knee-jerk reaction to someone pressuring him to buy something. But if you suggest that he look to the future and consider what it will face if he has an accident while uninsured, he is more likely to buy a policy from you. Why? Because he is thinking how much he might regret it if he doesn’t comply with your request.

“People do not spontaneously anticipate regret,” and when they do, they “use this anticipation to guide their decisions,” said Matthew Crawford, a University of Indiana psychologist, writing in the Journal of Experimental Social Psychology. Anticipating regret focuses a person’s attention on negative outcomes.