The Nonlinear Development of Emotion Differentiation: Granular Emotional Experience Is Low in Adolescence

People differ in how specifically they separate affective experiences into different emotion types-a skill called emotion differentiation or emotional granularity. Although increased emotion differentiation has been associated with positive mental health outcomes, little is known about its development. Participants ( N = 143) between the ages of 5 and 25 years completed a laboratory measure of negative emotion differentiation in which they rated how much a series of aversive images made them feel angry, disgusted, sad, scared, and upset. Emotion-differentiation scores were computed using intraclass correlations. Emotion differentiation followed a nonlinear developmental trajectory: It fell from childhood to adolescence and rose from adolescence to adulthood. Mediation analyses suggested that an increased tendency to report feeling emotions one at a time explained elevated emotion differentiation in childhood. Importantly, two other mediators (intensity of emotional experiences and scale use) did not explain this developmental trend. Hence, low emotion differentiation in adolescence may arise because adolescents have little experience conceptualizing co-occurring emotions.