# Dual Process Theory
Dual Process Theory proposes that cognition operates through two distinct systems: **System 1** (fast, automatic, intuitive, effortless) and **System 2** (slow, deliberate, analytical, effortful). Popularized by [[Daniel Kahneman]] in *[[Thinking Fast and Slow (book)]]*, the framework explains why we make predictable errors—System 1 generates quick judgments that System 2 often accepts without scrutiny.
System 1 excels at pattern recognition, intuition, and routine decisions but produces systematic biases. System 2 can override System 1 but requires effort and is easily depleted. Most thinking is System 1; we only engage System 2 when surprised or when stakes are high. The theory influences [[Behavioral Economics]], [[Nudge Theory]], and understanding of cognitive biases.
## The Two Systems
| System 1 | System 2 |
|----------|----------|
| Fast, automatic | Slow, deliberate |
| Effortless | Effortful |
| Intuitive | Analytical |
| Prone to biases | Can override biases |
| Always on | Lazy, easily depleted |
## References
- Kahneman, Daniel. *[[Thinking Fast and Slow (book)]]* (2011)
- Stanovich, Keith. *Rationality and the Reflective Mind* (2011)
## Related
- [[Daniel Kahneman]]
- [[Intuition]]
- [[Cognitive Biases]]
- [[Heuristics]]
- [[Behavioral Economics]]
- [[Thinking Fast and Slow (book)]]