Dual processing theory
IB Psychology· Cognitive approach· 11 min read
1. Core concept
Dual-processing theory says thinking runs on two systems. System 1 is fast, automatic, intuitive and effortless; System 2 is slow, deliberate, analytic and effortful. Everyday judgements lean on System 1, which is efficient but prone to systematic biases; System 2 can override it but is easily 'lazy'. The model explains why capable people still make predictable reasoning errors.
2. Key studies
IB Psychology answers must be supported by named studies. Learn these to cite as evidence:
Tversky & Kahneman (1981)
People reversed their risk preferences depending on whether identical outcomes were framed as gains or losses. — The framing effect shows fast, intuitive System-1 processing overriding consistent, rational choice.
3. Evaluation (AO3)
Strength — unifying and predictive — One model organises many separate biases and predicts when errors appear (under time pressure, low effort).
Limitation — a metaphor, not two brain systems — 'Two systems' is a useful simplification; the sharp dichotomy is debated and may overstate how separate the processes really are.
4. Scope
5. Common Pitfalls
Wrong move:
Describing a bias (anchoring, framing) without presenting the dual-processing model it belongs to.
Why:
A frequently penalised misconception in IB Psychology exams.
Correct move:
For thinking-and-decision-making questions the dual-processing model is the core answer; the biases are the supporting evidence for it.
Going deeper
- Anchoring biasanchoring is a System-1 bias explained by this model (COG_1).
- Confirmation biasconfirmation bias likewise reflects System-1 processing (COG_5).