Contrary to 84pct of experts polled, children's delay of gratification times are increasing over the past 50 years in a fifth of a standard deviation increase in ability per decade, mirroring IQ gains seen over decades

Kids These Days! Increasing delay of gratification ability over the past 50 years in children. ohn Protzko. Intelligence, Volume 80, May–June 2020, 101451, https://doi.org/10.1016/j.intell.2020.101451

Highlights
• 50 years of administering the ‘Marshmallow Test’ shows children can delay gratification for longer, in over 30 studies
• 260 experts in cognitive development were polled before analysis to predict the result, 84% predicted incorrectly
• The magnitude of increase is 0.18 SDs per decade, nearly identical to secular gains in IQ, suggesting a possible common cause

Abstract: Have children's ability to delay gratification decreased since the past? We analyze the past 50 years of data on the Marshmallow test of delay of gratification; where children must wait to get two preferred treats of their choosing; if they cannot wait, they only get one. Here we provide comprehensive 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 children are getting worse or are no different than those of the past. Contrary to this prediction, we show delay of gratification times are increasing over the past 50 years, corresponding to a fifth of a standard deviation increase in ability per decade. This mirrors the magnitude of secular gains in IQ seen over decades.

Keywords: Self-regulationMetasciencePredictionFlynn effects