Laugh (laughter)

Characteristics and production

Physiologically, laughter is produced by coordinated action of the respiratory system, the larynx and facial muscles. A typical laugh consists of a series of short, audible breaths with variable pitch and intensity. People describe different qualities of laughter—such as chuckles, giggles, snorts, guffaws and cackles—based on loudness, duration and the part of the vocal tract that predominates. Some people emphasize throat sounds; others use the nasal passages or more vocalized tones.

Forms, writing and representation

In writing and online communication, laughter is represented in many ways. Traditional transcriptions include "ha ha," "heh," "hehe," or "haha," while abbreviations such as "LOL" (laughing out loud) are common in digital messages. Performers, writers and actors use different types of laugh to convey character: a timid giggle differs from a loud guffaw or a sardonic snort. For information about the sound of laughter as a vocal phenomenon, see vocal sound.

Development and history

Human infants begin to laugh early in life, typically within the first few months; an often-cited age range is around three to four months. Early laughter may start as an expression of surprise or an involuntary vocal reaction, and it quickly becomes a powerful social cue that elicits responsive smiles and mirroring from caregivers. Cultural practices influence when and how people laugh, but the capacity to laugh appears to be widespread across human societies.

Social functions, benefits and examples

Laughter plays several social and psychological roles. It helps build and maintain social bonds, signals shared understanding, reduces tension in awkward situations, and can act as a nonverbal form of communication. Many people report that laughter reduces stress temporarily, increases feelings of connection, and may raise pain tolerance. Laughter also features in organized activities such as comedy, group entertainment and therapeutic settings. Common everyday triggers include jokes, playful teasing, unexpected situations and physical tickling—people often laugh when they hear a joke or are tickled.

Contagion, culture and notable facts

Laughter is notably contagious: hearing someone laugh often provokes laughter in listeners, a phenomenon linked to social mirroring and empathy. Television and online platforms have amplified this effect; for example, clips of laughing infants or comic moments circulate widely on sites such as YouTube. Public figures have sometimes reacted visibly to such clips—an often-cited anecdote describes a royal visit to Google headquarters where the monarch and the Duke of Edinburgh were reported to laugh together at a video.

Distinctions and disorders

Not all laughter is a sign of genuine amusement. "Nervous laughter" can accompany fear or discomfort, and pathological conditions such as pseudobulbar affect produce inappropriate or involuntary episodes of laughing and crying. In clinical and social contexts it is important to distinguish spontaneous, socially motivated, and neurologically driven laughter to understand underlying causes and responses.

Types (summary)

• Giggle: light, high-pitched, often associated with amusement or nervousness.
• Chuckle: quiet, restrained laugh.
• Guffaw: loud, hearty laugh.
• Snort or cackle: laughter with notable nasal or harsh sounds.