Distrust easy fluency
Treat "this feels obviously right" as a flag to check, not a signal to proceed.
Why it works
Cognitive ease — when information is fluent, familiar, or repeated — is read by System 1 as truth and competence. Smooth, confident-feeling conclusions are therefore often under-examined. Deliberately introducing a little disfluency (slowing down, writing it out) re-engages System 2’s scrutiny.
How to do it
- When a claim feels instantly and effortlessly true, treat the ease itself as suspicious.
- Slow the input: read it again, restate it in your own words, ask for the source.
- Distinguish "I’ve heard this a lot" from "this is well supported."
Evidence
Processing fluency reliably increases judged truth and confidence (the "illusory truth" effect, the mere-repetition effect), demonstrated across many experiments. (rct)
Fluency is usually a fine guide for routine judgments; the cost of distrusting it everywhere is paralysis. Reserve scrutiny for consequential claims.
Sources
- Hasher, Goldstein & Toppino (1977), illusory truth / frequency-validity effect
- Alter & Oppenheimer (2009), review of fluency effects on judgment
Common mistake
Mistaking familiarity for verification — concluding something is true because you’ve encountered it repeatedly rather than because it’s been checked.
Practice this with IX Coach
More practices for Thinking, Fast and Slow, Made Usable
- Notice which system is driving
Before deciding, ask whether this is a System 1 (snap) or System 2 (effortful) problem.
- Slow down for high-stakes, irreversible decisions
Match deliberation to the cost of being wrong: spend System 2 where reversal is hard.
- Consider the opposite
Actively argue the case against your first conclusion before accepting it.
- Take the outside view (base rates)
Estimate using the track record of similar cases, not the vivid details of your own.
- Watch for anchoring
Recognize when an arbitrary first number is silently dragging your estimate.