There is evidence that optimists experience better physical and mental health and a higher quality of life compared to pessimists. The benefits of optimism may even transmit to the next generation. Our aim is to study to what extent and how parental optimism shapes the lives of offspring. We hypothesize that optimistic parents are generally more effective in regulating their emotions and transmit these skills to the next generation. To test this hypothesis, we study whether parental optimism predicts more dyadic affective flexibility during interactions between parents and their young children (~ age 2.5). Parent-child dyadic affective flexibility refers to the ability of a parent and child to adjust to contextual demands by shifting between emotional states together and is an early precursor of adaptive emotion regulation. Data are used from a large-scale longitudinal cohort study. Parental optimism is assessed with the self-report Life Orientation Test (LOT-R). Videotaped observations of parent-child interactions during goal-directed tasks that include a frustration are used to code child and parent affect (negative externalizing, negative internalizing, neutral, interest, and positive) with an adapted version of the SPecific Affect (SPAFF) coding system. Dyadic affective flexibility is derived from state space grids in Mangold INTERACT. Videos are currently being coded and first results based on ~ 80 child-parent dyads will be presented and discussed at the symposium. If parent-child dyadic affective flexibility is indeed higher for more optimistic parents, this may indicate important advantages of optimism for the next generation. This presentation was part of the symposium ‘Innovations in measuring, understanding and improving emotion (regulation) dynamics across time)’.