ABSTRACT
The earliest dual process theory which I specified in any detail is known as the heuristic-analytic theory. It was first published in journal article (Evans, 1984a) which caused little interest at the time. The theory became popular, however, following publication five years later of my book Bias in Human Reasoning (Evans, 1989) in which it was applied to a range of phenomena in the psychology of thinking, reasoning and decision making. In terms of more generic dual process theories (see Section 6) the terms heuristic and analytic refer to a distinction between Type 1 (fast, preconscious, automatic, high capacity) and Type 2 (slow, conscious, deliberative, low capacity), also sometimes attributed to System 1 and 2. It had a structure which is common (but not universal) in dual process theories of reasoning and decision making, which I later described as default-interventionist (Evans, 2007b). That is to say Type 1 processing occurs first and may or may not be intervened upon by later and more effortful Type 2 processing. We have already seen one application of the theory, in the case of the Wason selection task, in the study of Evans (1996) reproduced in Section 2.
