Science-- there's something for everyone

Friday, October 19, 2012

Marshmallow test notwithstanding, children are more rational than we thought


You’ve probably heard about the ‘marshmallow test’ for impulse control. Briefly, young children are given one marshmallow and told that if they can delay eating it for a few minutes, they’ll get a second marshmallow. The original experiment was conducted in the 60’s at Stanford University, but cognitive scientists and parents have been repeating the experiment ever since. Here's an example you might enjoy.




Why such interest in whether kids can resist a marshmallow? When those children were revisited later in life, the ones who had been able to delay gratification at age four seemed to have some huge advantages. For example, they had higher SAT scores and suffered from less substance abuse. Apparently, being able to postpone eating a tasty treat as a preschooler has implications for one’s success in life. Or does it? Not so fast.

Celeste Kidd, Holly Palmeri and Richard Aslin of the University of Rochester repeated the marshmallow test, but with a twist. This time, prior to giving children their first marshmallow, they set up scenarios where a facilitator was seen as either ‘reliable’ or ‘unreliable’. Children were offered a handful of crayons or stickers for a project and told that if they could wait, the staffer would go and fetch a much better collection of materials. For one group of kids, the adult did indeed return with some particularly enticing supplies (reliable).  For the second group of children, the adult came back empty handed (unreliable), explaining that there weren’t any more materials after all. After two experiences with the adult being either reliable or unreliable, the kids were presented with their marshmallows and the real test began.

The kids who had been paired with a reliable facilitator were able to wait an average of four times longer than the children who had been twice disappointed by an unreliable adult. This difference may have been underestimated by the fact that each test was terminated after 15 minutes, by which point only one out of fourteen children in the unreliable group but nine out fourteen in the reliable group still had their marshmallow. In other words, many of the kids in the reliable group might have been willing to wait far longer.

While young children clearly have difficulty with impulse control, this study contradicts the view that differences in that control are purely innate. Instead, the data suggest that the majority of young children use a rational process to decide whether or not to wait for a reward. After all, if you can’t trust someone to bring you a second marshmallow, you might as well go ahead and eat the one in front of you.

The University of Rochester researchers explain:



Celeste Kidd, Holly Palmeri, & Richard N. Aslin (2012). Rational snacking: Young children’s decision-making on the marshmallow task is moderated by beliefs about environmental reliability Cognition DOI: 10.1016/j.cognition.2012.08.004