The Marshmallow Test does not reliably predict adult functioning

Jessica F. Sperber, Deborah Lowe Vandell, Greg J. Duncan, Tyler W. Watts, Delay of gratification and adult outcomes: The Marshmallow Test does not reliably predict adult functioning. Child Development, 00, 1-15. 29 July 2024 https://doi.org/10.1111/cdev.14129

Abstract: This study extends the analytic approach conducted by Watts et al. (2018) to examine the long-term predictive validity of delay of gratification. Participants (n = 702; 83% White, 46% male) completed the Marshmallow Test at 54 months (1995–1996) and survey measures at age 26 (2017–2018). Using a preregistered analysis, Marshmallow Test performance was not strongly predictive of adult achievement, health, or behavior. ...