In a classic experiment with preschoolers, walter mischel gave children a choice to eat one marshmallow now or two marshmallows when he returned a few minutes later. mischel was testing in the children. cognitive reasoning intuitive reasoning the capacity to delay gratification moral reasoning

Mischel was testing the capacity to delay gratification.
Delayed gratification refers to the ability to resist the initial temptation to take a reward immediately, and rather wait a bit to get an even better reward later. So, he wanted to see if children would eat one marshmallow immediately or wait a bit for him to return so that they can eat two marshmallows instead of just one.