You've no doubt heard of Walter Mischel's Marshmallow Test and its followup study, which examined the relationship between delayed gratification (the ability to resist the temptation to eat a marshmallow right away with the promise of more if you succeed) and overall life success. Celeste Kidd, a U Rochester doctoral candidate, has published a paper in Cognition challenging Mischel's findings, arguing that children from more unpredicatable circumstances may choose the single marshmallow because they have a rational basis for suspecting that the experimenter is lying to them about the additional marshmallows that await them if they follow instructions.
The Marshmallow Test is sometimes used to suggest that people are poor because they have low self-control; Kidd's paper implies that poor people behave wisely when they grab opportunities as they present themselves, because they are often lied to when it comes to promises of greater rewards down the road.
Celeste Kidd adds:
The video discusses a study we recently did at the University of Rochester that revisits the original 'marshmallow task' experiments from Stanford in the 1960's. Our results suggest children's waiting during the marshmallow task might actually result from a rational decision-making process–not just a deficiency in self-control.
In the Stanford experiments, most children–75% of 3- to 5-year-olds in one study–appeared unable to resist the temptation of an immediate low-value reward (one marshmallow now) over a future high-value one (two marshmallows after 15 minutes). There's a popular misconception about these studies, though, which is that waiting for the second marshmallow is always the right thing to do. In fact, there are a lot of situations in which waiting is a bad idea. If you're skeptical that a second marshmallow will ever become available–or you believe there's a risk that your first marshmallow might be taken away–you should enjoy the smaller reward right away.
In our study, we preceded marshmallow-task testing with evidence that the experimenter running the study was either reliable or unreliable. Children who believed the experimenter was reliable then waited about four times longer before eating the marshmallow than those who thought she was unreliable (12 minutes vs. 3 minutes). These results suggest that children engage in very sensible decision-making that considers environmental reliability. They may also provide an alternative explanation for why marshmallow wait-times correlate with later life success–successful people grow up in reliable situations. Broadly, the study illustrates that children build a model of the reliability of others' behavior–and use this model to inform their decisions.