'Sleeping on It' Won't Help You Make a Better Decision

Whether a major life change or a decision on how to handle a tricky work conflict, common advice is to simply “sleep on it,” because making a decision in the morning somehow allows you to make the better choice. But apparently that's not the case.

According to a new study published in the Journal of Behavioral Decision Making. Harvard Business School marketing professor Uma Karmarkar, University of Massachusetts-Amherst psychology professor Rebecca Spencer, and Stanford Graduate School of Business marketing professor Baba Shiv, looked into the sleep-centered expression by asking graduate students to choose between four similar laptop bags, then studying their final choice after either a night of sleep or a day without sleep.

Those who slept on their decisions were able to remember more positive qualities about all the bags in general, but they felt less certain about their final choice of bag than those who hadn’t slept. Although sleep offers a number of physiological benefits, improving your decision-making ability is not one of them.

“Nothing about sleeping on it makes your feel better,” says Karmarkar in a Harvard Business School release. “If you are trying to make people feel more confident about and rule out options, there could be some benefit to stepping away for a period, but not necessarily sleeping on it.”

The study focused on a relatively impersonal subject (laptop bags) and used a relatively homogenous participant group (graduate students). Although there were a couple obvious limitations to the study, it still might be worth considering making important future decisions without “sleeping on it.”