Emotions play an important role in social interactions and as such, they are critical in creating engaging and believable characters that users can interact with.   Although there has been significant research on emotions, from a computational perspective, one area scarcely explored is the process of Emotional Contagion (EC). Emotional Contagion is the process through which a person's emotional state is influenced by other people's emotions. This process is especially important in group situations where the emotional states of individuals influence the behavior of others.   Our goal was to develop a computational model, based on the Emotional Contagion Scale (ECS), that would enrich group dynamics on virtual environments. This model supports agents with different susceptibilities to contagion, and also the influence of their extroversion personality trait and interpersonal relationships (intimacy and power difference) on the contagion process. It has been also included the process of emotional mood decay, as observed in humans. With these elements characterizing the agents at an individual level, this model can simulate a wide variety of social phenomena.   To evaluate the model, we developed a game prototype where the player (the main character) goes on a journey with two other characters (one with and another without our model).   The results suggest that players perceived differences in the emotional contagion susceptibility between those characters and considered the model-based agent significantly more enjoyable and friendlier.
['Joana Dimas', 'Gonçalo Duarte Garcia Pereira', 'Pedro Alexandre Santos', 'Rui Prada', 'Ana Paiva']
"I'm happy if you are happy.": a model for emotional contagion in game characters