Dual-process theories of reasoning: Contemporary issues and developmental applications

In this paper, I discuss the current state of theorising about dual processes in adult performance on reasoning and decision making tasks, in which Type 1 intuitive processing is distinguished from Type 2 reflective thinking. I show that there are many types of theory some of which distinguish modes rather than types of thinking and that assumptions about underlying cognitive architecture vary. I show that some dual-system theories have been replaced recently by the idea that we have two or more distinct ‘minds’ with different evolutionary histories. I also present the most recent formulation of my own account of dual processing within hypothetical thinking theory, at a level more easily applied to performance on specific tasks. I then consider implications for cognitive development, pointing out that while Type 2 thinking is clearly linked to the development of cognitive ability, it combines and competes with multiple Type 1 processing systems which persist in adult cognition, each of which could have their own developmental time course. Hence, while dual-process theories can and should inspire much research and theory in cognitive development, the derivation of predictions for cognitive development is far from straightforward.