Across languages and cultures, caregivers tend to have one thing in common: they speak to babies in a happy, sing-song way that they would never use with adults. This type of speech, sometimes called “infant-directed speech,” “baby talk,” or “motherese,” is a particularly exaggerated form of emotionally expressive speech. In a recent study, researchers found that toddlers respond to this emotionally expressive speech in different ways, and these varied responses are linked with their social, linguistic, and cognitive abilities.