Why do animals play? Well, why shouldn’t they? The real question is: Why does the existence of action carried out for the sheer pleasure of acting, the exertion of powers for the sheer pleasure of exerting them, strike us as mysterious? What does it tell us about ourselves that we instinctively assume that it is?

An alternative school of Darwinism emerged in Russia emphasizing cooperation, not competition, as the driver of evolutionary change. In 1902 this approach found a voice in a popular book, Mutual Aid: A Factor of Evolution , by naturalist and revolutionary anarchist pamphleteer Peter Kropotkin. In an explicit riposte to social Darwinists, Kropotkin... See more