Never underestimate the power of positive thinking—even if it isn't your own. A new working paper from the Harvard Business School found that praise from friends and family not only makes us feel good, it actually improves our problem-solving skills.

Before the study, approximately half of the participants were instructed to email friends, family, or co-workers, and ask them to send in examples of different times they’d seen the participant at their best. When the participants arrived to begin the experiment, researchers gave them the letters their loved ones had written. Meanwhile, the other half were given no special encouragement. 

Some of the letters were incredibly touching. For instance, one read: 

I remember the time when you stayed up all night to make sure that I knew I was worth more than what my high school bullies would try to make me believe. Your compassion and words allowed me to feel loved in a world that is often cruel. You reminded me of my potential to be a great yet humble person. During those blinding moments, you showed me a lot more about myself that I might not have known until years later.

Researchers found that those who received the letters performed significantly better on the tests than those who didn’t. For example, both groups were asked to solve “the Duncker candle problem,” in which a candle must be mounted on a wall so that wax does not drip on the floor. Participants were given only the candle, a box of tacks, and a box of matches to complete the task. While 51 percent of the first group were able to solve the problem (by using the box of tacks as a platform for the candle), only 19 percent of the second group were successful. 

According to the researchers, the study illustrates the positive impact of “best-self activation” on problem-solving abilities: When people are reminded of a time in the past when they were at their best, they’re more likely to rise to the occasion once again. And while thinking back on proud moments can be helpful, the researchers found that best-self activations were most effective when they came from participants’ social networks. Positive memories from friends, family, and colleagues have a real impact on our ability to successfully perform tasks under pressure. So the next time you’re stressing out about a big project at work, it might help to turn to your friends for a few words of encouragement. And if you want to bring out the best in your employees or co-workers, remind them of a time they did a great job. 

[h/t: New York Magazine]