gelotology
The study of humour and laughter, and its effects on the body.
uncountable
Let's not develop a cult of laughology (though the study of laughter in medicine has already been christened gelotology from the Greek root meaning "laughter.") Humor is an important and documented adjunct in the life of both the well and the unwell, but as a therapy it rarely can stand alone.
Where it comes from
From Ancient Greek γέλωτος (gélōtos) (the genitive of γέλως (gélōs, “laughter”)) + English -logy (suffix denoting the study of a particular subject), coined by the anthropologist and linguist Edith Trager with participation from the American psychiatrist William F. Fry, Jr. (1924–2014) in March 1964.
Adapted from the Wiktionary entry gelotology (CC BY-SA 4.0).