Will-Power in Children & Future Success | The Marshmallow Experiment by Stanford University’s Walter Mischel, PhD. This experiment (originally done in the 1970s) highlights how delayed gratification in children may predict life outcomes such as SAT scores, educational attainment, body mass index (BMI), social skills & substance abuse issues. Replication of this study on larger scales suggests that economic background, rather than willpower, better predicts children’s behavior & long-term success