Ripples of Emotion: Unraveling the Dynamics of Emotion Flows and User Engagement in Online Healthcare Communities

Online healthcare communities are an important source of peer support for individuals managing chronic illnesses, mental health challenges, and stigmatized health conditions. Emotional interactions are central to this support, and yet their effects may extend well beyond the original conversation. Our study examines how emotional experiences accumulate over time by analyzing 65,740 reply interactions in an online HIV community. We find that emotional exchanges generate lasting ripple effects across the community. Users who receive more positive sentiment are more likely to remain active in writing replies and express positive sentiment in later interactions, whereas receiving more negative sentiment is associated with lower participation and less positive expression. We also find that users’ own emotional expressions shape how others subsequently respond to them: Positive expressions are associated with more replies and more positive responses, whereas negative expressions are associated with fewer and less positive responses. These effects extend across users, threads, topics, and local social clusters and are especially strong for feeling-oriented messages. The findings suggest that community managers should monitor emotional patterns at the community level, not only within individual conversations, and consider interventions that encourage constructive emotional exchanges while preventing negative emotional dynamics from becoming self-reinforcing.