You've probably heard of Walter Mischel's marshmallow experiment before: Stanford researchers left kids alone in a room with a single marshmallow, promising that if the tyke could keep its hands off the sugary snack for up to 15 minutes, they'd get a second marshmallow.
According to a New Yorker article from last year, a child's ability to delay gratification and control his or her impulses was a solid predictor of how they would later fare on their SATs (better than I.Q.), as well as larger behavioral problems:
Once Mischel began analyzing the results, he noticed that low delayers, the children who rang the bell quickly, seemed more likely to have behavioral problems, both in school and at home. They got lower S.A.T. scores. They struggled in stressful situations, often had trouble paying attention, and found it difficult to maintain friendships. The child who could wait fifteen minutes had an S.A.T. score that was, on average, two hundred and ten points higher than that of the kid who could wait only thirty seconds.