Serve and return: the core interaction

Baby serves, you return — like a game of tennis

The Harvard Center on the Developing Child calls the back-and-forth between a young child and a caring adult "serve and return" — comparing it to a lively game of tennis. Your baby "serves" with a babble, a gesture, a cry, or a look, and you "return" with eye contact, words, or a hug.

These responsive exchanges are described as essential to how a young brain's architecture gets built — they help build and strengthen neural connections that support communication and social skills, and lay a foundation for later, more complex thinking. When responses are consistently inconsistent, harmful, or simply absent, the brain's architecture does not develop as expected.