Being able to carefully perceive and distinguish the rich complexity in emotional experiences is a key component of psychological interventions. We review research in clinical, social, and health psychology that offers insights into the adaptive value of putting feelings into words with a high degree of complexity (i.e., emotion differentiation or emotional granularity). According to recent research, upon experiencing intense distress, individuals who experience their emotions with more granularity are less likely to resort to maladaptive self-regulatory strategies such as binge drinking, aggression, and self-injurious behavior; show less neural reactivity to rejection; and experience less severe anxiety and depressive disorders. These findings shed light on how negative emotions and stressful experiences can be transformed by people’s emotion-differentiation skill. Besides basic research suggesting that emotion differentiation is an important developmental process, evidence suggests that interventions designed to improve emotion differentiation can both reduce psychological problems and increase various strands of well-being.