The CHATTER Project is a study of the factors that contribute to everyday communication and emotion socialization processes between parents and their one- and two-year-old toddlers. We aim to recruit an ethnically and socioeconomically diverse sample of toddlers and their families. The study includes daylong audio-recordings of parent-toddler emotional and verbal communication, a qualitative interview or parents’ emotion socialization beliefs, goals, and practices, and parent-report measures of toddler characteristics (i.e., temperament, language ability), parent characteristics (e.g., stress, mental health symptoms, emotion regulation), and parenting behaviors.