Dual-Process Theory
The idea that thinking comes in two modes — fast instinct and slow deliberation — now borrowed to describe two kinds of AI model.
Definition
Dual-process theory is the psychology idea, popularized by Daniel Kahneman, that human thinking runs in two modes: System 1, which is fast, automatic, and intuitive, like recognizing a face or sensing that something is off; and System 2, which is slow, effortful, and deliberate, like working through a long calculation. AI has borrowed the vocabulary heavily. Models that reason step by step before answering are described as doing System 2 thinking, while decision models that return an instant judgment with no visible deliberation are marketed as 'System One' models. The analogy is loose — these systems do not actually work the way human cognition does — but it has become common shorthand for the tradeoff between speed and deliberation.