The marshmallow test, redone with ten times as many children, found that a four-year-old's willpower mostly stopped predicting teenage success once family background was taken into account

The famous experiment seemed to show that a child who could resist one treat for two grew up to do better in life. A 2018 conceptual replication with a larger, more representative sample found a much weaker link, most of it explained by the home a child came from.