The Stanford marshmallow experiment was a study on delayed gratification in 1972 led by psychologist Walter Mischel, a professor at Stanford University. In this study, a child was offered a choice between one small but immediate reward, or two small rewards if they waited for a period of time. During this time, the researcher left the room for about 15 minutes and then returned. The reward was either a marshmallow or pretzel stick, depending on the child's preference. In follow-up studies, the researchers found that children who were able to wait longer for the preferred rewards tended to have better life outcomes, as measured by SAT scores, educational attainment, body mass index, and other life measures. A replication attempt with a sample from a more diverse population, over 10 times larger than the original study, ed only half the effect of the original study. The replication suggested that economic background, rather than willpower, explained the other half.
