What's your reading speed?

In the 1960s, a Stanford researcher named Walter Mischel conducted an experiment with four-year-olds that would become one of the most cited studies in psychology. He placed a marshmallow on a table in front of each child and told them: if they could wait fifteen minutes without eating it, they would receive a second marshmallow as a reward. Some children grabbed the treat immediately. Others struggled heroically, covering their eyes, turning away, or singing songs to distract themselves. What Mischel found over the following decades was striking: the children who had waited scored higher on their SATs, had better health outcomes, and reported greater satisfaction in their relationships. The ability to delay gratification, it seemed, was one of the most powerful predictors of success in nearly every domain of life. But the story doesn't end there. Later researchers revisited the data and found that the results were far more nuanced than originally reported. Family background, income, and the reliability of the adults in a child's environment all played a significant role. A child who had learned not to trust that the second marshmallow would ever arrive had a rational reason to eat the first one immediately.