The tendency to search for, interpret, favour, and recall information in ways that confirm one's pre-existing beliefs, while giving disproportionately less weight to disconfirming evidence.
In intelligence analysis
- Reporting that supports the working hypothesis is credited readily; contradicting reporting is discounted as unreliable or noisy.
- A leading hypothesis becomes self-reinforcing: each confirmatory item raises confidence without any genuine test against alternatives.
- Pairs with selective perception — information that conflicts with the model may never be registered at all.
Countermeasure
- Analysis of Competing Hypotheses (ACH) — list all plausible hypotheses and test all evidence against each, seeking evidence that distinguishes them rather than evidence that merely supports the favourite.
- Devil's Advocacy and red-teaming as explicit adversarial checks.
Related
- Cognitive Bias — the taxonomy this bias sits within
- Structured Analytic Techniques — ACH and related counters
- Groupthink — shared confirmation of a group view