The co-emergence of emotion vocabulary and organized emotion dynamics in childhood

Emotions change from one moment to the next. They have a duration from seconds to hours, and then transition to other emotions. Here we describe the early ontology of these key aspects of emotion dynamics. In five cross-sectional studies that combine parent surveys and ecological momentary assessment, we characterize how emotion duration and transitions change over the first five years of life, and how they relate to children’s language development. Over this developmental period, the duration of children’s emotions increased, and emotion transitions became increasingly organized by valence, such that children were more likely to transition between similarly valenced emotions. Children with these more mature emotion profiles also had larger vocabularies and produced labels for the tested emotions. These findings advance our understanding of emotion and communication by highlighting their intertwined nature in development and by charting how dynamic features of emotional experiences change over the first years of life.