In daily life, individuals frequently see others experience success, good luck, and happiness. Yet, people don't always share others' happiness or celebrate their good fortune. Even in close relationships, individuals can't always relate to their partners' successes or fully share their excitement. In several ongoing projects, we are examining potential barriers to positive empathy – such as stress, loneliness, and low self-esteem. We are also implementing interventions that will overcome these barriers and boost positive empathy in close relationships, as well as encourage the development of positive empathy in young children. Critically, we measure the impact of these interventions on the empathizer's own well-being and social functioning. We predict that experiencing positive empathy more frequently and intensely will improve empathizers' mental health and enhance their social relationships.