In an article in Psychological Science, researchers from NYU and UC Irvine report their replication and extension of the famous March Mellow test. The report shows strong bivariate correlations between a child’s ability to delay gratification just before entering school and both adolescent achievement and socioemotional behaviors.
They found a bivariate correlation that was only half the size of those reported in the original studies. The correlation reduced two thirds in the presence of controls for family background, early cognitive ability, and home environment. So was the later success related to their ability to delay, or were both success and that ability related to the background?