From BOLD Blog: Starting in the late 1960s, researchers conducted an experiment offering young children a choice between one marshmallow at the present or two in the future; it was later discovered that children who chose the latter option achieved more academic success, had fuller social lives, and experienced better health outcomes as adults. While the findings have often been interpreted to mean that self-control improves academic, social, and health outcomes, new evidence suggests that the outcomes have more to do with socioeconomic status.
“Children in more stable life circumstances have been given strong evidence that waiting pays off. Those better life circumstances, then, could be causally responsible for the positive later life outcomes associated with long waiting on the marshmallow test. We have a considerable amount of empirical evidence in support of this account. Unstable home environments lead to worse grades, lower test scores, more overeating, more substance abuse, more acting out. Of course a child with more parental support and resources is going to do better on their SATs—they’re likely attending a better school, don’t need to work a job, and more likely to have their parents hire them a tutor.
If children’s behavior in the marshmallow test reflects the expectations that they’ve formed throughout their lives, the longitudinal correlations should not be taken to mean that self-control is the ‘engine of success.’ We should not waste time and grant money trying to train self-control, nor should we commit to the implicit judgment behind these studies—that kids who fail to wait for the second marshmallow are inferior.”