laugh

Laughter is a physical response consisting of a series of vocalized exhalations and body movements that typically occur in reaction to humor or social cues. It is a universal human behavior, though its expression and triggers vary across cultures. Laughter can accompany a range of emotions, from amusement and joy to relief, nervousness, or social tension, and it is often contagious within groups.

Physiologically, laughter involves coordinated activity of respiratory, facial, and laryngeal muscles. The form of laughter that includes genuine facial muscle engagement is often described as Duchenne laughter, characterized by movements around the mouth and eyes, while non-Duchenne laughter may occur as a social signal without full facial involvement. Laughter can be spontaneous or voluntary, and its initiation involves cognitive appraisal of humorous or rewarding stimuli processed by multiple brain regions.

Functionally, laughter serves social purposes: it strengthens bonds, defuses awkward situations, signals affiliative intent, and can influence perceptions of status. Cultural norms shape what is considered appropriate laughter and when it is expected or discouraged. Types of laughter range from loud, hearty bursts to quiet giggles, snorts, or chortles, each with differing social connotations.

Health and well-being: research reports mixed but generally positive associations between laughter and mood, stress reduction, and perceived pain tolerance. Laughter therapy or humor interventions have been explored as complementary approaches in health care, though results vary by study design and individual differences. Laughter is not a cure, but it can contribute to short-term psychological relief and social connectedness.