Karl Groos was born. A professor of philosophy at the University of Basel in Switzerland, Groos developed an evolutionary theory of play that was years ahead of its time. In a number of landmark publications of the topic, most notably 'The Play of Animals' (1898) and 'The Play of Man' (1901), Groos argued that play provides an adaptive context in which children are able to acquire and develop the skills needed to prepare them for the tasks of life.

Writing about the biological significance of play, Groos famously stated that 'The very existence of youth is due in part to the necessity for play; the animal does not play because he is young, he has a period of youth because he must play.'