Dual-process thinking (System 1 and System 2)
A model of thinking as two kinds of process: fast, automatic, associative intuition (System 1) and slow, effortful, rule-based reasoning (System 2). Most judgements are made by the first and endorsed after the fact by the second.
What drives it
Explains where biases come from (System 1 shortcuts) and when they get corrected (System 2 stepping in, given time, motivation and spare capacity). For identification, it explains why impressions of a face form within a fraction of a second (Todorov's work) and why they persist unless deliberately checked.
How it shows
Work
Snap verdicts on candidates in the first minutes, with the rest of the interview spent confirming them. Decisions made tired or rushed, later defended with elaborate reasoning. Executives whose gut is excellent in a familiar domain with fast feedback (Klein's expert intuition) and poor in an unfamiliar one.
Relationships
The instant read on a partner's friends at dinner. The reply fired off in an argument versus what you would say after a walk. Late-night messages.
Self
A System 1 judgement arrives without effort and feels obvious. Whether to trust it depends on whether the domain gives quick, clear feedback; judging strangers rarely does.
What tells it apart
Amygdala hijack: An amygdala hijack is a high-arousal emotional takeover with visible physical signs; System 1 judgement is usually calm, quick and unnoticed.
Emotional reasoning: Emotional reasoning treats a feeling as proof; dual-process is a broader architecture, and many System 1 errors are cold and unemotional, such as a numeric anchor.
A test
Write down your quick verdict, then build the strongest case against it; if the verdict survives the deliberate check it was good intuition, if not, System 1 was running unsupervised.
Questions to carry
- Where did the first impression come from, and how much of it survives the strongest case against it?
- Which of my snap judgements about a face or a voice did I later defend with reasons I found afterwards?
How strong the research is
moderate. The distinction between fast intuitive and slow deliberate processing is well supported, but whether there are two distinct systems is disputed (Keren and Schul, 2009; Melnikoff and Bargh, 2018), and some priming findings popularised alongside it have failed to replicate.
Where it comes from
Jonathan Evans, 1970s–1980s; Seymour Epstein, 1990s; Keith Stanovich and Richard West, 2000 (System 1 and 2 labels); Daniel Kahneman, 2011 (Thinking, Fast and Slow)
Sources
- Amos Tversky and Daniel Kahneman, Judgment under Uncertainty: Heuristics and Biases (1974)
- Daniel Kahneman, Thinking, Fast and Slow (2011)