While many, indeed most preschoolers who managed to delay…
While many, indeed most preschoolers who managed to delay gratification on the Marshmallow Test continued to show good self-control for decades to come, self-control steadily decreased for some, whereas others who rang the bell soon showed the opposite pattern over the years, increasing their self-regulation as they matured.
— from The Heart in the Cockpit (Emotion/Awe/Anxiety/Regret/Empathy) · Marshmallow Test: Why Self-Control is the Engine of Success by Walter Mischel