The parallel processing model of belief bias: review and extensions

The idea that human behaviour is often influenced by competing processes that support unique responses is pervasive in psychological science. Its early origins can be found in Sigmund Freud’s belief that personality and behaviour derive from the constant interaction of conflicting conscious and unconscious psychological influences (see Frankish & Evans, 2009, for a comprehensive review of these ideas stretching all the way back to Plato). In modern psychology, such dual process theories have been developed to explain a whole range of psychological phenomena, including the operation of human memory (Jacoby, Toth, & Yonelinas, 1993), perceptual category learning (Ashby & Maddox, 2005), person perception (Chaiken & Trope, 1999), judgment and decision making (Epstein, 1994; Kahneman, 2011; Sloman, 1996), and reasoning (Evans & Over, 1996; Stanovich, 1999). In all cases, the presence of a conflict between competing responses is seen as diagnostic of dual processes at work.