In the realm of early childhood education, we often refer to “developmental domains,” the areas of development that occur simultaneously as children mature: physical, cognitive, social, and emotional. The domains are interconnected, meaning that development in one domain impacts the others, so you cannot really say that one domain is “more important” than any other. An effective early childhood curriculum promotes development across all domains.
However, one could argue that the emotional domain has the biggest overall impact on cognitive and social development. Research shows that healthy emotional development directly affects behavior, social relationships, and academic achievement. The connection between emotional and physical development is a little less obvious, but as children age, emotional development can certainly impact dietary and exercise habits, for better or for worse.
Source: Child Care Education Institute