Confronted with a baby—or puppy—most adults can’t stop themselves from dissolving into baby talk: “WHO’S the cutest? It’s YOU! YES it IS!” We slow down, increase our pitch by nearly an octave, and milk each vowel for all it’s worth. And even if the baby can’t speak yet, we mimic the turn-taking of a conversation.

This “parentese” is found across cultures, and babies exposed to more of it at home seem to do better at acquiring their home language. But it’s not all about instinct: a paper published in PNAS this week suggests that parents can be trained to improve their parentese and that this training gives their babies’ language a boost.

Learning to baby talk

Why does more parentese go hand-in-hand with language acquisition? It’s an open question. Recordings from parents and children in their homes show a correlation—the more parentese there is, the more likely the babies are to be a little more advanced with their language abilities. But is the parentese itself actually helping? And if so, how? Or is there another factor at play that boosts them both?