From The First Idea:
Through a field study, we have been able to show that the early capacities are mastered for the first time (and then continue to be further developed) during specific, predicted time intervals. [pp. 54]
No, I haven’t chased down the study yet and, no, I haven’t determined what these time periods are. I’m not done reading it. They argue that Piaget was kind of right, but that it wasn’t ringing the bell that led to causality. It was “I smile and Mother smiles back”, an emotionally laden lesson.
If they are right, then it makes sense that people with high “Emotional Quotient” would be more successful.