A form of paradoxical therapy in which the patient or client is enjoined to practise the very behaviour that needs to be eliminated. The US psychologist Knight Dunlap (1873–1949) introduced it in an article entitled ‘A revision of the Fundamental Law of Habit Formation’ in the journal Science in 1928, in which he reported: ‘The first opportunity which occurred for the testing of this method lay in an idiosyncrasy of my own in typewriting. For some years I have been annoyed, when typing rapidly, by an occasional transposition of the letters of a word, the word “the” being especially troublesome, so that in reading over a manuscript of my own typing I would sometimes find two, three or more of these transpositions into “hte.” … I now proceeded to try the typing of “hte” voluntarily, as a means of destroying it. I set to work deliberately and wrote about half a page, single spaced, of the “hte” combination, with the futuric thought that this was a “word” that I would not write in the future (unless deliberately or voluntarily). Somewhat over a week later, I followed this with a second “practice period,” writing less than a third of a page. This was over three months ago. Since that time I have typed many pages, some rapidly, but have not found on reading them over a single case of “hte”!’ (vol. 67, p. 361). Dunlap developed his theory further in an article in Scientific Monthly in 1930 and in a book entitled Habits: Their Making and Unmaking (1932, pp. 94–6, 163–4, 313–14). See also paradoxical intention.