What's the best strategy for making a tough decision?

The stock answer--or one of them--is to sleep on it. Sleep is supposed to help us make better decisions, eliminating end-of-day decision fatigue. Sleep has been shown to make people more creative, more attentive, less risky in their behavior, and less subject to their emotions. Indeed, there are a dozen articles on Inc.com alone that urge leaders who are stuck on a decision to put it aside until morning.

Now a new study shows that sleep may not do much to help us be more confident in our decision making. Instead, participants in the study, asked to postpone a decision until morning, were less certain in their choice, not more so. Uma Karmarkar, an assistant professor of business administration at Harvard Business School, and one of the researchers of the study, told Harvard's Working Knowledge newsletter, "Nothing about sleeping on it makes you feel better [about the decision you made], and it might make you feel worse."

The big caveat about the study is that the participants were asked to choose between four options that didn't differ that much, and their choices didn't have dire consequences. Even after the study was completed, there was no "right" or "wrong" answer that was suddenly revealed.

In some cases, that's a lot like life: We often spend way too much energy trying to decide between two (or more) options that are only slightly different, but just different enough to cause us plenty of grief. It would be hard to test for the other extreme, and put study participants in a situation that would have dire consequences for those who made poor decisions.

What we have, instead, are a group of graduate students who were asked to choose between four laptop bags. They were all of similar quality, but had different features. Some students chose a bag right away, and then were asked to sleep on their decision. Others were sent away for 12 hours before choosing. The students weren't told the study was about sleep, and anyone who took a mid-day nap was dropped from the study.

When those who had slept were then asked how confident they were in their choice, they said they were less confident, compared with those who didn't sleep between seeing the bags and choosing one. Students were better able to recall the positive features of the bags after sleeping, so it's possible that everything looked rosy, making it harder to rule out one bag or the other.