Dual‐Process and Dual‐System Theories of Reasoning

Dual‐process theories hold that there are two distinct processing modes available for many cognitive tasks: one (type 1) that is fast, automatic and non‐conscious, and another (type 2) that is slow, controlled and conscious. Typically, cognitive biases are attributed to type 1 processes, which are held to be heuristic or associative, and logical responses to type 2 processes, which are characterised as rule‐based or analytical. Dual‐system theories go further and assign these two types of process to two separate reasoning systems, System 1 and System 2 – a view sometimes described as ‘the two minds hypothesis’. It is often claimed that System 2 is uniquely human and the source of our capacity for abstract and hypothetical thinking. This study is an introduction to dual‐process and dual‐system theories. It looks at some precursors, surveys key work in the fields of learning, reasoning, social cognition and decision making, and identifies some recent trends and philosophical applications.