Laughter happens thirty times more often around other people than alone, and this film asks why that matters. In London, neuroscientist Sophie Scott explains her research into laughter as a social behavior that builds relationships and lowers stress, with lab scenes showing how contagious it really is. A research team at Alpen-Adria-Universität Klagenfurt studies how humor changes the dynamic between therapist and patient, finding it can ease symptoms rather than just lighten the mood. German doctor and TV presenter Eckart von Hirschhausen appears through his foundation Humor hilft heilen, which runs workshops training hospital nursing staff to use humor in everyday interactions with patients, not by telling jokes but by softening tense moments. The documentary moves between these settings, letting scientists, therapists, and hospital workers describe what they have observed firsthand, and builds a picture of laughter as a measurable social and physiological tool rather than mere entertainment.