The second marshmallow Baseball T-Shirt

The Stanford marshmallow experiment was a series of studies on delayed gratification in the late 1960s. In these studies, a child was given a marshmallow immediately and, if the child waited for 15 minutes without eating the marshmallow, a second one would be given. During the waiting time the tester left the room. 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.