Physiology of laughter thumb|alt=Three quarter length portrait of sixty-year-old man, balding, with white hair and long white bushy beard, with heavy eyebrows shading his eyes looking thoughtfully into the distance, wearing a wide lapelled jacket.|Charles Darwin in his later years In 1872, Charles Darwin published one of the first "comprehensive and in many ways remarkably accurate description of laughter in terms of respiration, vocalization, facial action and gesture and posture" (Laughter). In this early study Darwin raises further questions about who laughs and why they laugh; the myriad responses since then illustrate the complexities of this behaviour. To understand laughter in humans and other primates, the science of gelotology (from the Greek '', meaning laughter) has been established; it is the study of laughter and its effects on the body from both a psychological and physiological perspective. While jokes can provoke laughter, laughter cannot be used as a one-to-one marker of jokes because there are multiple stimuli to laughter, humour being just one of them. The other six causes of laughter listed are social context, ignorance, anxiety, derision, acting apology, and tickling. As such, the study of laughter is a secondary albeit entertaining perspective in an understanding of jokes.
Physiology of laughter thumb|alt=Three quarter length portrait of sixty-year-old man balding with white hair and long white bushy beard with heavy eyebrows shading his eyes looking thoughtfully into the distance wearing a wide lapelled jacket|Charles Darwin in his later years In 1872 Charles Darwin published one of the first "comprehensive and in many ways remarkably accurate description of laughter in terms of respiration vocalization facial action and gesture and posture" (Laughter) In this early study Darwin raises further questions about who laughs and why they laugh; the myriad responses since then illustrate the complexities of this behaviour To understand laughter in humans and other primates the science of gelotology (from the Greek '' meaning laughter) has been established; it is the study of laughter and its effects on the body from both a psychological and physiological perspective While jokes can provoke laughter laughter cannot be used as a one-to-one marker of jokes because there are multiple stimuli to laughter humour being just one of them The other six causes of laughter listed are social context ignorance anxiety derision acting apology and tickling As such the study of laughter is a secondary albeit entertaining perspective in an understanding of jokes