In 1984, researcher James Flynn published a paper demonstrating that students’ measured IQ scores on standardized tests had been steadily increasing in several parts of the world since at least the 1930s. There has been much debate about why this is the case and what it means. Flynn’s own hypothesis is that it represents an increase in individual’s ability to perform abstract problem solving, likely due to increased exposure to abstract problem solving in formal educational settings.
There’s an interesting pre-print paper, Kids these days, that attempts to do the same thing for a common psychological experiment to determine children’s ability to delay gratification. In the marshmallow experiment, children are left alone with a reward such as a marshmallow or cookie. The children are told that if they don’t eat the reward for a short period of time, they will receive a larger reward–such as two cookies–when the researcher returns.
The interesting thing is that the study found that children today are better at delaying gratification in the marshmallow test today than they were in previous generations.
Here we provide the first evidence on whether children’s ability to delay gratification has truly been decreasing, as theories of technology or a culture of instant gratification have predicted. Before analyzing the data, we polled 260 experts in cognitive development, 84% of who believed kids these days are getting worse or are no different. Contrary to this prediction, kids these days are better able to delay gratification than they were in the past, corresponding to a fifth of a standard deviation increase in ability per decade.
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Overall, contrary to not only popular wisdom, but also expert prediction, kids these days are better at delaying gratification on the marshmallow test—and they are getting better. Each year, all else equal, corresponds to an increase in ability to delay gratification by another six seconds. This represents a little over a minute per decade; given the sample average standard deviation (SD = 5.858 seconds) this is a little less than a fifth of a standard deviation per decade (effect size = .18S Ds). What is notable about this is it corresponds to the fifth of a standard deviation per decade observed in increases in IQ (Flynn, 1984)