Emotions in co-rumination: An evolutionary developmental perspective

Co-rumination is a developmental psychology concept that encompasses the social process of rehashing, speculation, mutual encouragement, and negative affect about a problem, originally described in Rose's (2002) observation in youths' same-sex friendships. The negative valence of the emotional content and verbal processing of a social problem are both integral to the construct, such that co-rumination facilitates trade-offs between intimacy and internalizing symptoms in same-sex friendships. Emotional contagion facilitates nonverbal communication in humans and has biological underpinnings that communicate emotional content and encourage synchrony between conspecifics. Co-rumination and associated processes may represent part of a suite of adaptations that facilitate alliance formation with non-kin. This chapter summarizes the recent literature on co-rumination, emotional contagion, empathy, and their biological underpinnings, and places these processes in the broader context of human sociality.