Dual Process Theory

What is dual process theory?

Dual-process theories distinguish relatively automatic responses from reasoning that requires deliberate mental effort. They are a family of models, rather than one theory of two separate brain systems.

In Evans and Stanovich’s account, Type 1 processes generate default responses autonomously. Type 2 processing draws heavily on working memory and supports hypothetical thinking: considering possibilities and, sometimes, revising an initial response.

The popular names “System 1” and “System 2” are useful shorthand. They should not turn into two little characters in the head, one fast and foolish, the other slow and wise. The useful question is how a judgment was made and whether further reasoning would help.

Dual processing example

Consider this illustrative problem: a notebook and a pen cost $12 together, and the notebook costs $10 more than the pen. What does the pen cost? An immediate answer might be $2, obtained by subtracting $10 from $12. Checking that answer exposes a problem: a $2 pen would require a $12 notebook, giving a $14 total. A $1 pen and an $11 notebook satisfy both conditions.

If someone first produces the quick answer and then deliberately checks the two conditions, that sequence illustrates an autonomous response followed by effortful reasoning. The example does not claim that everyone gives the same first answer. A quick answer can be correct, and a deliberate check can contain mistakes.

Source: Dual-Process Theories of Higher Cognition: Advancing the Debate.