Consider the Opposite

Minutes

Deliberately generate the reasons your current judgment might be wrong before acting on it, which measurably reduces confirmation-driven error in a way that merely trying to be fair does not.

How to do it

  1. 1State your current conclusion in one sentence, including how confident you are.
  2. 2Ask: "If the opposite were true, what would I expect to see?" List at least three observations that would fit the opposite conclusion.
  3. 3Ask whether any of those observations are already in front of you and you discounted them.
  4. 4Ask how you would evaluate this same evidence if it supported the other side. If you would call it weak there, it is weak here.
  5. 5Re-state your conclusion and confidence. Movement of even a little is the point; the technique is not meant to reverse every belief.

What to say

  • “Suppose I am wrong about this. What is the best evidence I would then be ignoring?”
  • “If someone I disagreed with brought me this study, what would I say about its sample size?”

When to use it

  • •Evaluating a study, article, or statistic that confirms what you already believed.
  • •Hiring, investing, or diagnostic judgments where first impressions are strong.
  • •Before sharing political content that makes your side look good and the other side look foolish.

Counters

Confirmation Bias ExploitationBelief PerseveranceCherry PickingCard StackingHostile Media EffectNaive RealismOverconfidence EffectIllusory CorrelationAnecdotal FallacyMisleading VividnessNutpickingHasty Generalization

Evidence and how strong it is

Lord, Lepper & Preston (1984) found that instructing people to "consider the opposite" eliminated biased assimilation of mixed evidence on capital punishment, while instructing them to "be unbiased" did nothing; Hirt & Markman (1995) showed that generating any plausible alternative, not only the exact opposite, produces the debiasing. Reviews of debiasing (Larrick 2004) rate it among the few reliably effective cognitive strategies. Evidence strength: moderate to strong across several decades of lab studies. Effects amount to substantially reducing bias rather than abolishing it, and they depend on the person actually generating specific alternatives rather than nodding at the instruction.

Cautions
  • Generating too many alternatives can backfire: when listing reasons feels difficult, people conclude the alternative must be unlikely (Sanna, Schwarz & Stocker 2002). Aim for two or three good ones.
  • The technique corrects reasoning; it does not settle facts. After considering the opposite, go and check.
  • Do not use it as a performance of open-mindedness in a debate; it is a private tool for your own judgment.
  1. Lord, C. G., Lepper, M. R., & Preston, E. (1984). Considering the Opposite: A Corrective Strategy for Social Judgment. Journal of Personality and Social Psychology, 47(6), 1231-1243 · link
    The founding experiments: consider-the-opposite instructions removed biased assimilation where "be unbiased" instructions failed.
  2. Hirt, E. R., & Markman, K. D. (1995). Multiple Explanation: A Consider-an-Alternative Strategy for Debiasing Judgments. Journal of Personality and Social Psychology, 69(6), 1069-1086
    Evidence that generating any plausible alternative outcome, not only the opposite, debiases judgment.
  3. Sanna, L. J., Schwarz, N., & Stocker, S. L. (2002). When Debiasing Backfires: Accessible Content and Accessibility Experiences in Debiasing Hindsight. Journal of Experimental Psychology: Learning, Memory, and Cognition, 28(3), 497-502
    The caution that asking for many alternatives can backfire because difficulty of generation is read as implausibility.
  4. Larrick, R. P. (2004). Debiasing. In D. J. Koehler & N. Harvey (Eds.), Blackwell Handbook of Judgment and Decision Making (pp. 316-337). Blackwell
    Review placing consider-the-opposite among the cognitive debiasing strategies with the best evidence.
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