The question
Introspection means looking inward at our own mental life. Can it tell us what caused a choice? Richard Nisbett and Timothy Wilson distinguish having a thought from knowing the process that produced it. Their question concerns access to that process. A person can know what they chose and still misread why they chose it. [1]
The method
This is a review and theoretical argument, not one large experiment. The authors draw on studies that compare people’s reports with evidence about what shaped their responses. Does the reported reason match what the study found? That is the key test. A fluent answer to “why?” is not enough. [1] One study asked 52 people to judge four identical pairs of nylon stockings. [2] The pair on the right was chosen far more often. [2] The example gives the larger question a clear form: a choice among identical goods can reflect something besides the product’s quality.
The findings
People can miss an influence, a change in their response, or the link between the two. [1] Nisbett and Wilson propose that people often draw on plausible theories to explain their behavior. We know what usually sounds like a good reason, then use that knowledge to account for a choice. The account may feel like a memory of how we decided. That feeling does not show direct access to the mental process. [1]
The limits
The authors do not claim that every report is wrong. When the true cause is clear and fits a plausible account, people can report it correctly. But a correct answer alone does not tell us how they reached it. [1] Later work gives reasons to keep using some kinds of report. In the abstract of their 1980 paper, K. Anders Ericsson and Herbert Simon outline a model of when such reports can be sound. That makes how you ask for the report important. Not all accounts of thought are equally weak. [3]