Let me say from the start, that I’m deeply suspicious of the Marshmallow Test.
This is the simple test administered to young children that purports to measure the impulse control of four-year old children. Basically, the testers give the children a single marshmallow. The children are then told that they may eat the marshmallow immediately. If the children wait, however, they will be given a second marshmallow.
The results apparently have dramatic predictive ability. From economist Arnold Kling's blog:
Who would ever guess that a brief observation of a four-year old alone with a marshmallow would be an excellent predictor of college entrance exam scores — twice as good a predictor as IQ test scores?
In one of the most amazing developmental studies ever conducted, Walter Mischel of Stanford created a simple test of the ability of four year old children to control impulses and delay gratification. Children were taken one at a time into a room with a one-way mirror. They were shown a marshmallow. The experimenter told them he had to leave and that they could have the marshmallow right then, but if they waited for the experimenter to return from an errand, they could have two marshmallows. One marshmallow was left on a table in front of them. Some children grabbed the available marshmallow within seconds of the experimenter leaving. Others waited up to twenty minutes for the experimenter to return.
In a follow-up study (Shoda, Mischel & Peake, 1990), children were tested at 18 years of age and comparisons were made between the third of the children who grabbed the marshmallow (the "impulsive") and the third who delayed gratification in order to receive the enhanced reward ("impulse controlled").
The third of the children who were most impulsive at four years of age scored an average of 524 verbal and 528 math. The impulse controlled students who scored 610 verbal and 652 math! This astounding 210 point total score difference on the SAT was predicted on the basis of a single observation at four years of age! The 210 point difference is as large as the average differences between that of economically advantaged versus disadvantaged children and is larger than the difference between children from families with graduate degrees versus children whose parents did not finish high school! At four years of age gobbling a marshmallow now v. waiting for two later is twice as good a predictor of later SAT scores than is IQ. Poor impulse control is also a better predictor of later delinquency than is IQ (Block, 1995).
Economists tend to see this as a measure of time preference. Some say it is an indicator of general intelligence. I’ve heard investors talk about this as a test of whether someone has the character to be an investor for the long-term. Even short-term traders have told me it is a good test of the ability to see a strategy through.
I’m not convinced. The first thing that raises a red flag with me is that the marshmallow test better predicts SAT scores than IQ tests. Now, SATs are basically IQ tests. But IQ tests are actually better predictors of general intelligence than SAT scores. This means that both the marshmallow test and the SAT are testing for something in addition to intelligence.
What is it that they are testing? I think it’s compliance with rules set by authorities. The kids who do not eat the marshmallow are not exercising "self-control." They are submitting to outside control. Similarly, I suspect that those who follow instructions carefully probably are able to outperform their IQs on the SATs.
It actually makes sense for the SAT to test for compliant personalities. The SAT is supposed to test for college aptitude, not just general intelligence. Following rules and obeying authority is a critical skill for success not just in educational settings, but in our increasingly rigid society. Conformity to the rules set by authorities and trust that promised rewards will be delivered are probably very important to success.
To put it slightly differently, the SAT seems to be prejudiced against high IQ non-conformists and those skeptical of authority—the kids who didn’t wait for the marshamallow.
To put it in an overly simplistic and very contemporary context: the marshmallow eaters are the political equivalent of the Tea Partiers; the delayers are the folks voting for the incumbents of either party.
Watch this irresistibly cute video, which we picked up from Business Insider, and tell me who you like better: the little red-haired girl who gobbles the marshmallow or the blond kid who obeys the rules and then stuffs his face?