Consider the opposite
Actively argue the case against your first conclusion before accepting it.
Key takeaways
- What it is: Actively argue the case against your first conclusion before accepting it.
- Why it works: Confirmation bias makes System 1 retrieve only evidence that fits the conclusion it already reached. Deliberately asking "what would make this wrong?" forces retrieval of disconfirming evidence, counteracting the one-sided search that produces overconfidence.
- Evidence: Backed by randomized trials / meta-analyses.
- Avoid: Generating a token counter-argument you never believed, then dismissing it. The exercise only works if you genuinely try to build the opposing case.
Why it works
Confirmation bias makes System 1 retrieve only evidence that fits the conclusion it already reached. Deliberately asking "what would make this wrong?" forces retrieval of disconfirming evidence, counteracting the one-sided search that produces overconfidence.
How to do it
- 1State your conclusion, then ask: "Suppose this is wrong — why?"
- 2List concrete reasons and evidence that point the other way.
- 3Only then re-weigh; the goal is calibration, not flipping for its own sake.
What the evidence says
RCT / meta-analysis"Consider the opposite" is one of the better-supported debiasing techniques, shown in experiments to reduce overconfidence and hindsight and confirmation effects.
Honest caveat: It reduces but does not eliminate bias, and it costs effort — people drop it under time pressure.
- — Lord, Lepper & Preston (1984), considering the opposite reduces biased assimilation, J. Personality & Social Psychology
Common mistake
Generating a token counter-argument you never believed, then dismissing it. The exercise only works if you genuinely try to build the opposing case.
IX Coach plays a structured devil’s advocate, surfacing the strongest counter-case to a conclusion you are leaning toward.
Practice this with IX Coach →