The Emotion Understanding and Regulation (EUR) study is a longitudinal research design with three timepoints that followed children from the preschool period through school age. For this study, children participated with both their mothers and their fathers at separate timepoints. Children’s teachers also completed questionnaires at the second timepoint. The EUR study assesses children’s emotion expression and regulation in tasks designed to elicit both positive and negative emotions. All timepoints of this study also included parent-child emotion discourse tasks, so we could better understand the ways parents are talking to their children about both positive and negative emotions.