In a nutshell, it is developing the capacity to experience and regulate emotions, form secure relationships, and explore and learn.[i] Positive social-emotional development provides a critical foundation for lifelong development and learning.
[i] ZERO TO THREE (2010). Tips for promoting social and emotional development. Washington, DC. Accessed from https://www.zerotothree.org/resources/225-tips-for-promoting-social-emotional-development.