Is the Marshmallow Test a Good Measure of the Capacity to Delay Gratification?

Abstract

Children’s wait time in the marshmallow test is commonly interpreted as a measure of their capacity to delay gratification. However, children’s motivation to demonstrate the capacity to delay gratification in this task is contingent on them initially preferring and pursuing delayed rewards and understanding the mutually exclusive relation between the two possible rewards. By failing to sufficiently measure delay-discounted reward preferences, or whether children properly understand and trust the choices presented to them, standard approaches to the marshmallow test risk conflating children’s understanding of the task and their resulting reward preferences with their capacity to delay gratification. This paper discusses how reward preferences and subsequent wait time in the marshmallow test can be influenced by variation in how children (i) understand delays, (ii) understand reward contingencies, and (iii) trust in the reward contingencies presented to them. We discuss how variance in each of these factors impacts reward preferences and how methodological approaches to the marshmallow test give rise to the reliance on assumed understanding and trust. We present evidence against assuming universal understanding and trust in children, highlight the implications of accepting these assumptions, and provide novel methodological recommendations for less conflated measures of delay maintenance behavior. Overall, we suggest that the marshmallow test’s capacity to answer meaningful questions about delay maintenance behavior be furthered by implementing more rigorous methodological approaches.