The term 'brainwashing' was born in the crucible of war. Not as one might expect, the Second World War - though it was retrospectively applied to Nazi techniques - but the Korean War. Some emerged from prisoner of war camps as, apparently, converted Communists. Unnerved by their behaviour the US began to investigate what their CIA operative Edward Hunter had in 1950 publicly christened 'brainwashing'.

The word itself, according to Hunter, is a translation of the Chinese concept of xi-nao or hsi-nao, a colloquial rendering of szu-hsiang-kai-tsao ('thought reform'). However the concept of hsi-nao, 'heart washing' or 'cleansing the mind' using meditation, is much older than Communism. Hunter claims that it dates to the time of Meng K'o, a fourth-century BC Confucian thinker.