{"data":{"biases":[{"id":"variable-ratio-reinforcement","name":"Variable Ratio Reinforcement","domain":"motivation","mechanism":"Rewards delivered after an unpredictable number of responses produce the highest and most extinction-resistant response rates of any reinforcement schedule.","replication_status":"robust","typical_effect_size":"Very large and highly reliable across species","confidence":0.91,"caveats":["This is the mechanism underlying slot machines and loot boxes. It is the single highest-risk item in this corpus.","Regulated as gambling in several jurisdictions when tied to monetary spend.","Applying it to engagement metrics reliably produces compulsive use rather than value."],"countermeasures":["Track time spent against value received.","Impose external session limits."],"exploitation_risk":90,"canonical_source":{"authors":"Ferster, C. B., & Skinner, B. F.","year":1957,"title":"Schedules of Reinforcement","venue":"Appleton-Century-Crofts"},"related_effects":[]},{"id":"cognitive-load","name":"Cognitive Load","domain":"cognition","mechanism":"Working memory is sharply limited. Load imposed by presentation (extraneous load) competes with load intrinsic to the task, and once total load exceeds capacity, performance and completion collapse rather than degrade gently.","replication_status":"robust","typical_effect_size":"Large for learning and task-completion outcomes","confidence":0.9,"caveats":["Reducing extraneous load is nearly always safe. Reducing intrinsic load means removing genuine information, which can mislead."],"countermeasures":["Slow down and externalise the decision when a page feels overwhelming."],"exploitation_risk":10,"canonical_source":{"authors":"Sweller, J.","year":1988,"title":"Cognitive Load During Problem Solving: Effects on Learning","venue":"Cognitive Science, 12(2), 257-285","doi":"10.1207/s15516709cog1202_4"},"related_effects":["millers-law","choice-overload","processing-fluency"]},{"id":"confirmation-bias","name":"Confirmation Bias","domain":"cognition","mechanism":"Information is sought, weighted, and remembered in ways that favour an existing belief, and disconfirming evidence is subjected to harsher scrutiny than confirming evidence.","replication_status":"robust","typical_effect_size":"Large and pervasive","confidence":0.9,"caveats":["Applies to your own A/B test interpretation as much as to your audience.","Not reduced by intelligence or expertise; expertise often strengthens it by supplying better counter-arguments."],"countermeasures":["Actively seek the strongest disconfirming evidence before concluding.","Pre-register what result would change your mind."],"exploitation_risk":35,"canonical_source":{"authors":"Wason, P. C.","year":1960,"title":"On the Failure to Eliminate Hypotheses in a Conceptual Task","venue":"Quarterly Journal of Experimental Psychology, 12(3), 129-140","doi":"10.1080/17470216008416717"},"related_effects":["availability-heuristic","overconfidence"]},{"id":"survivorship-bias","name":"Survivorship Bias","domain":"cognition","mechanism":"Analysis restricted to surviving cases systematically distorts conclusions, because the failures that would contradict the pattern have been removed from the sample.","replication_status":"robust","typical_effect_size":"Can invert conclusions entirely rather than merely bias them","confidence":0.9,"caveats":["Directly undermines \"successful companies do X\" reasoning, including most growth advice.","Your own customer testimonials are a survivorship-biased sample by construction — churned users do not write them."],"countermeasures":["Ask what happened to the cases that are not in the sample.","Seek the failure population explicitly."],"exploitation_risk":30,"canonical_source":{"authors":"Brown, S. J., Goetzmann, W., Ibbotson, R. G., & Ross, S. A.","year":1992,"title":"Survivorship Bias in Performance Studies","venue":"Review of Financial Studies, 5(4), 553-580","doi":"10.1093/rfs/5.4.553"},"related_effects":["base-rate-neglect","availability-heuristic","confirmation-bias"]},{"id":"anchoring","name":"Anchoring","domain":"decision","mechanism":"An initially presented number becomes the reference point for subsequent numeric judgement. Adjustment away from it is insufficient, so the final estimate stays biased toward the anchor even when the anchor is known to be arbitrary or irrelevant.","replication_status":"robust","typical_effect_size":"d≈0.5 to 1.0 depending on anchor extremity","confidence":0.88,"caveats":["Attenuates but does not vanish with domain expertise.","Implausibly extreme anchors can trigger reactance and reverse the effect.","Requires the judgement to be genuinely uncertain; a buyer who knows the market price is barely moved."],"countermeasures":["Consider the opposite: actively generate reasons the anchor is wrong.","Evaluate against an independently sourced market rate before viewing the offer."],"exploitation_risk":35,"canonical_source":{"authors":"Tversky, A., & Kahneman, D.","year":1974,"title":"Judgment under Uncertainty: Heuristics and Biases","venue":"Science, 185(4157), 1124-1131","doi":"10.1126/science.185.4157.1124"},"related_effects":["framing-effect","decoy-effect","left-digit-effect"]},{"id":"negativity-bias","name":"Negativity Bias","domain":"emotion","mechanism":"Negative information is weighted more heavily than equivalently intense positive information in attention, memory, and judgement.","replication_status":"robust","typical_effect_size":"Large and pervasive across domains","confidence":0.88,"caveats":["Explains why a single negative review outweighs several positive ones, and why unresolved complaints are disproportionately costly.","Fear-based marketing exploits this and reliably damages brand trust over time."],"countermeasures":["Weight positive evidence deliberately to offset the asymmetry."],"exploitation_risk":40,"canonical_source":{"authors":"Baumeister, R. F., Bratslavsky, E., Finkenauer, C., & Vohs, K. D.","year":2001,"title":"Bad Is Stronger Than Good","venue":"Review of General Psychology, 5(4), 323-370","doi":"10.1037/1089-2680.5.4.323"},"related_effects":["loss-aversion","availability-heuristic"]},{"id":"hyperbolic-discounting","name":"Hyperbolic Discounting","domain":"decision","mechanism":"Future rewards are discounted steeply in the near term and shallowly later, so preferences reverse as a deadline approaches. A choice made calmly in advance is reversed in the moment.","replication_status":"robust","typical_effect_size":"Large and consistent across domains","confidence":0.88,"caveats":["Explains why annual plans convert worse than monthly despite better value — the cost is immediate and the saving is distant.","Also explains why free trials work: the cost is deferred past the discounting horizon.","Exploiting it to obscure long-term cost is precisely what negative-option rules target."],"countermeasures":["Compute total cost over the full commitment before deciding.","Pre-commit while calm rather than deciding at the deadline."],"exploitation_risk":45,"canonical_source":{"authors":"Ainslie, G.","year":1975,"title":"Specious Reward: A Behavioral Theory of Impulsiveness and Impulse Control","venue":"Psychological Bulletin, 82(4), 463-496","doi":"10.1037/h0076860"},"related_effects":["loss-aversion","default-effect"]},{"id":"ambiguity-aversion","name":"Ambiguity Aversion","domain":"decision","mechanism":"Known risks are preferred to unknown ones, even when the unknown option has equal or better expected value. Missing information is treated as adverse.","replication_status":"robust","typical_effect_size":"Large and highly reliable","confidence":0.88,"caveats":["The best argument for publishing pricing. A hidden price is read as a bad price.","Also explains why vague trust badges underperform specific, verifiable claims."],"countermeasures":["Distinguish \"unknown\" from \"bad\" — ask rather than assume."],"exploitation_risk":15,"canonical_source":{"authors":"Ellsberg, D.","year":1961,"title":"Risk, Ambiguity, and the Savage Axioms","venue":"Quarterly Journal of Economics, 75(4), 643-669","doi":"10.2307/1884324"},"related_effects":["loss-aversion","status-quo-bias"]},{"id":"planning-fallacy","name":"Planning Fallacy","domain":"decision","mechanism":"Task completion time is systematically underestimated because planning focuses on the specific successful path and neglects the distribution of similar past outcomes.","replication_status":"robust","typical_effect_size":"Large; underestimates of 30-50% are routine","confidence":0.88,"caveats":["Persists even among people who know about it and who have personally missed similar estimates before.","Relevant to your own roadmap as much as to how you present setup time to customers."],"countermeasures":["Take the outside view: how long did comparable past tasks actually take?","Estimate from a reference class, not from the plan."],"exploitation_risk":20,"canonical_source":{"authors":"Buehler, R., Griffin, D., & Ross, M.","year":1994,"title":"Exploring the \"Planning Fallacy\": Why People Underestimate Their Task Completion Times","venue":"Journal of Personality and Social Psychology, 67(3), 366-381","doi":"10.1037/0022-3514.67.3.366"},"related_effects":["overconfidence","base-rate-neglect"]},{"id":"social-proof","name":"Social Proof","domain":"social","mechanism":"Under uncertainty, the behaviour of similar others is used as evidence about the correct action, because imitation is a cheap and usually reliable inference.","replication_status":"robust","typical_effect_size":"Field effects commonly 5-30% behaviour change","confidence":0.87,"caveats":["Strength scales with perceived similarity of the referent group, not with raw numbers.","Advertising low adoption backfires: it communicates the opposite norm.","Fabricated counts, fake testimonials, and invented \"12 people viewing\" widgets are unlawful commercial practices in the EU and actionable under FTC rules."],"countermeasures":["Ask whether the referent group actually shares your constraints."],"exploitation_risk":40,"canonical_source":{"authors":"Cialdini, R. B.","year":1984,"title":"Influence: The Psychology of Persuasion","venue":"Harper Business"},"related_effects":["authority","unity"]},{"id":"illusory-truth","name":"Illusory Truth Effect","domain":"cognition","mechanism":"Repeated statements are judged more likely to be true than novel ones, because familiarity is misread as evidence of prior verification. The effect operates even when the person knows the correct answer.","replication_status":"robust","typical_effect_size":"d≈0.4 meta-analytically; persists across delays","confidence":0.87,"caveats":["Works on statements the person could evaluate correctly if prompted — knowing better is not protective.","This is the mechanism behind misinformation persistence. Using it to make a weak claim feel true is deception, not marketing.","Repeating a *correction* can paradoxically entrench the original claim if the falsehood is restated in the process."],"countermeasures":["Check the source of a familiar-feeling claim rather than trusting the feeling.","Track whether you believe something because of evidence or because of exposure."],"exploitation_risk":55,"canonical_source":{"authors":"Hasher, L., Goldstein, D., & Toppino, T.","year":1977,"title":"Frequency and the Conference of Referential Validity","venue":"Journal of Verbal Learning and Verbal Behavior, 16(1), 107-112","doi":"10.1016/S0022-5371(77)80012-1"},"related_effects":["processing-fluency","mere-exposure","availability-heuristic"]},{"id":"processing-fluency","name":"Processing Fluency","domain":"cognition","mechanism":"Ease of mental processing is misattributed to properties of the stimulus itself, so material that is easier to read is judged more true, more familiar, and more likeable.","replication_status":"robust","typical_effect_size":"Small to moderate, but extremely broad in scope","confidence":0.86,"caveats":["Fluency raises believability regardless of accuracy, which is why clear writing carries an ethical obligation to be correct.","Excessive simplification can reduce perceived expertise for technical audiences."],"countermeasures":["Judge claims on evidence, not on how effortless they were to read."],"exploitation_risk":15,"canonical_source":{"authors":"Reber, R., Winkielman, P., & Schwarz, N.","year":1998,"title":"Effects of Perceptual Fluency on Affective Judgments","venue":"Psychological Science, 9(1), 45-48","doi":"10.1111/1467-9280.00008"},"related_effects":["mere-exposure","cognitive-load"]},{"id":"base-rate-neglect","name":"Base Rate Neglect","domain":"decision","mechanism":"Specific, vivid case information dominates judgement while background frequency is underweighted, producing badly calibrated probability estimates.","replication_status":"robust","typical_effect_size":"Large; attenuates when frequencies are presented as natural counts","confidence":0.86,"caveats":["Substantially reduced by expressing probabilities as natural frequencies (\"8 in 1,000\") instead of percentages.","Directly relevant to how you present conversion statistics and testimonial evidence."],"countermeasures":["Ask for the denominator before accepting any rate."],"exploitation_risk":30,"canonical_source":{"authors":"Kahneman, D., & Tversky, A.","year":1973,"title":"On the Psychology of Prediction","venue":"Psychological Review, 80(4), 237-251","doi":"10.1037/h0034747"},"related_effects":["availability-heuristic","confirmation-bias"]},{"id":"framing-effect","name":"Framing Effect","domain":"decision","mechanism":"Logically equivalent descriptions of the same outcome produce different preferences, because gains and losses are evaluated against a reference point rather than in absolute terms. Gain frames encourage risk aversion; loss frames encourage risk seeking.","replication_status":"robust","typical_effect_size":"d≈0.5, large in the classic Asian-disease paradigm","confidence":0.85,"caveats":["Effect size shrinks substantially with numerate audiences and with joint (side-by-side) evaluation.","Loss framing raises attention but also raises anxiety and can suppress conversion for considered purchases."],"countermeasures":["Restate the offer in the opposite frame before deciding."],"exploitation_risk":30,"canonical_source":{"authors":"Tversky, A., & Kahneman, D.","year":1981,"title":"The Framing of Decisions and the Psychology of Choice","venue":"Science, 211(4481), 453-458","doi":"10.1126/science.7455683"},"related_effects":["loss-aversion","anchoring"]},{"id":"authority","name":"Authority","domain":"social","mechanism":"Signals of legitimate expertise or position shift compliance, because deferring to credible expertise is normally an efficient shortcut around costly evaluation.","replication_status":"robust","typical_effect_size":"Large for compliance with legitimate authority","confidence":0.85,"caveats":["Depends on perceived legitimacy in the relevant domain; borrowed authority from an unrelated field is easily detected and backfires.","Displaying certifications or affiliations you do not hold is fraud, not persuasion."],"countermeasures":["Verify the credential is real and relevant to this specific claim."],"exploitation_risk":35,"canonical_source":{"authors":"Milgram, S.","year":1963,"title":"Behavioral Study of Obedience","venue":"Journal of Abnormal and Social Psychology, 67(4), 371-378","doi":"10.1037/h0040525"},"related_effects":["social-proof"]},{"id":"reactance","name":"Psychological Reactance","domain":"motivation","mechanism":"A perceived threat to behavioural freedom produces motivational arousal to restore it, often by doing the opposite of what is urged. This is the ceiling on persuasive pressure.","replication_status":"robust","typical_effect_size":"Moderate to large where the freedom threat is explicit","confidence":0.85,"caveats":["The single most important brake on every other effect in this corpus. Aggressive application of scarcity, urgency, or social proof triggers it and reverses the intended direction.","Stronger in individualist cultures and among people with high trait autonomy.","Phrases that restore choice (\"but it is up to you\") measurably reduce it."],"countermeasures":["Notice whether you are refusing on the merits or refusing to be pushed."],"exploitation_risk":5,"canonical_source":{"authors":"Brehm, J. W.","year":1966,"title":"A Theory of Psychological Reactance","venue":"Academic Press"},"related_effects":["scarcity","social-proof","commitment-consistency"]},{"id":"halo-effect","name":"Halo Effect","domain":"social","mechanism":"A salient positive attribute biases evaluation of unrelated attributes, without the evaluator being aware the transfer occurred.","replication_status":"robust","typical_effect_size":"Moderate to large","confidence":0.85,"caveats":["Why visual polish raises perceived reliability and security — attributes the design cannot actually speak to.","Cuts both ways: one visible defect drags unrelated judgements down with it."],"countermeasures":["Evaluate each attribute against evidence specific to it."],"exploitation_risk":35,"canonical_source":{"authors":"Nisbett, R. E., & Wilson, T. D.","year":1977,"title":"The Halo Effect: Evidence for Unconscious Alteration of Judgments","venue":"Journal of Personality and Social Psychology, 35(4), 250-256","doi":"10.1037/0022-3514.35.4.250"},"related_effects":["processing-fluency","authority"]},{"id":"overconfidence","name":"Overconfidence","domain":"decision","mechanism":"Confidence in judgements exceeds their accuracy, appearing as overestimation of performance, overplacement relative to others, and excessive precision in interval estimates.","replication_status":"robust","typical_effect_size":"Large for precision; direction of overplacement varies with task difficulty","confidence":0.85,"caveats":["Moore & Healy show the three forms dissociate — on hard tasks people often *under*place themselves while remaining overprecise.","Do not treat \"people are overconfident\" as a single uniform effect."],"countermeasures":["Widen every interval estimate; calibration training measurably helps.","Track prediction accuracy over time."],"exploitation_risk":20,"canonical_source":{"authors":"Moore, D. A., & Healy, P. J.","year":2008,"title":"The Trouble with Overconfidence","venue":"Psychological Review, 115(2), 502-517","doi":"10.1037/0033-295X.115.2.502"},"related_effects":["planning-fallacy","confirmation-bias","dunning-kruger"]},{"id":"status-quo-bias","name":"Status Quo Bias","domain":"decision","mechanism":"Disproportionate preference for the current state, arising from anticipated regret being greater for action than for inaction.","replication_status":"robust","typical_effect_size":"Moderate to large, increases with number of alternatives","confidence":0.84,"caveats":["Strengthens as options multiply, compounding with choice overload."],"countermeasures":["Ask whether you would choose the status quo if starting fresh today."],"exploitation_risk":25,"canonical_source":{"authors":"Samuelson, W., & Zeckhauser, R.","year":1988,"title":"Status Quo Bias in Decision Making","venue":"Journal of Risk and Uncertainty, 1(1), 7-59","doi":"10.1007/BF00055564"},"related_effects":["default-effect","loss-aversion","sunk-cost-fallacy"]},{"id":"reciprocity","name":"Reciprocity","domain":"social","mechanism":"Receiving an unrequested benefit creates a felt obligation to return it, sustained by strong and near-universal social norms against free-riding.","replication_status":"robust","typical_effect_size":"Moderate to large; roughly doubles compliance in classic field studies","confidence":0.84,"caveats":["The gift must feel genuine and unconditional. An obvious quid pro quo triggers reactance instead.","Personalisation and unexpectedness matter more than monetary value."],"countermeasures":["Distinguish a genuine gift from an opening move in a sales sequence."],"exploitation_risk":30,"canonical_source":{"authors":"Regan, D. T.","year":1971,"title":"Effects of a Favor and Liking on Compliance","venue":"Journal of Experimental Social Psychology, 7(6), 627-639","doi":"10.1016/0022-1031(71)90025-4"},"related_effects":["commitment-consistency"]},{"id":"sunk-cost-fallacy","name":"Sunk Cost Fallacy","domain":"decision","mechanism":"Prior irrecoverable investment increases willingness to continue, because abandoning would make the earlier expenditure feel wasted, despite being irrelevant to the forward-looking decision.","replication_status":"robust","typical_effect_size":"d≈0.5","confidence":0.83,"caveats":["Deliberately engineering sunk cost to suppress cancellation is a retention dark pattern and an FTC enforcement target."],"countermeasures":["Evaluate only forward costs and benefits; treat prior spend as gone."],"exploitation_risk":55,"canonical_source":{"authors":"Arkes, H. R., & Blumer, C.","year":1985,"title":"The Psychology of Sunk Cost","venue":"Organizational Behavior and Human Decision Processes, 35(1), 124-140","doi":"10.1016/0749-5978(85)90049-4"},"related_effects":["ikea-effect","status-quo-bias"]},{"id":"unity","name":"Unity (Shared Identity)","domain":"social","mechanism":"Influence rises sharply when the source is perceived as sharing an identity with the target — not merely similar to them, but of the same group. Even arbitrary group assignment produces measurable ingroup favouritism.","replication_status":"robust","typical_effect_size":"Ingroup favouritism is large and reliable, even with minimal groups","confidence":0.83,"caveats":["The underlying minimal-group finding is robust; Cialdini’s specific \"unity\" packaging is a later synthesis rather than an independently tested construct.","Claiming an identity you do not hold is detected quickly and inverts the effect into distrust.","Requires genuine shared category membership, not demographic targeting dressed up as kinship."],"countermeasures":["Ask whether the claimed shared identity is verifiable."],"exploitation_risk":40,"canonical_source":{"authors":"Tajfel, H., Billig, M. G., Bundy, R. P., & Flament, C.","year":1971,"title":"Social Categorization and Intergroup Behaviour","venue":"European Journal of Social Psychology, 1(2), 149-178","doi":"10.1002/ejsp.2420010202"},"related_effects":["social-proof","authority"]},{"id":"availability-heuristic","name":"Availability Heuristic","domain":"decision","mechanism":"Probability is judged by the ease with which instances come to mind, so vivid, recent, or emotionally charged events are systematically overweighted.","replication_status":"robust","typical_effect_size":"Moderate","confidence":0.82,"caveats":["Manufacturing vivid fear to sell a remedy is a well-known deceptive pattern."],"countermeasures":["Seek base rates before trusting a vivid anecdote."],"exploitation_risk":45,"canonical_source":{"authors":"Tversky, A., & Kahneman, D.","year":1973,"title":"Availability: A Heuristic for Judging Frequency and Probability","venue":"Cognitive Psychology, 5(2), 207-232","doi":"10.1016/0010-0285(73)90033-9"},"related_effects":["negativity-bias"]},{"id":"peak-end-rule","name":"Peak-End Rule","domain":"memory","mechanism":"Retrospective evaluation of an experience is driven largely by its most intense moment and its ending, while duration is substantially neglected.","replication_status":"robust","typical_effect_size":"Large for retrospective evaluation","confidence":0.82,"caveats":["Governs remembered experience, not experienced utility. A genuinely long ordeal with a pleasant ending is still an ordeal.","Using it to paper over a bad core experience produces good survey scores and bad retention."],"countermeasures":["Evaluate the whole experience deliberately, not just how it ended."],"exploitation_risk":25,"canonical_source":{"authors":"Kahneman, D., Fredrickson, B. L., Schreiber, C. A., & Redelmeier, D. A.","year":1993,"title":"When More Pain Is Preferred to Less: Adding a Better End","venue":"Psychological Science, 4(6), 401-405","doi":"10.1111/j.1467-9280.1993.tb00589.x"},"related_effects":["serial-position-effect"]},{"id":"commitment-consistency","name":"Commitment and Consistency","domain":"social","mechanism":"After a small public or effortful commitment, people act consistently with it, because inconsistency threatens self-concept and social standing.","replication_status":"robust","typical_effect_size":"d≈0.3 to 0.5 for foot-in-the-door","confidence":0.8,"caveats":["The initial request must be small enough to be accepted, and large enough to feel like a choice.","Requires genuine voluntariness; coerced commitments do not generalise."],"countermeasures":["Re-evaluate the current request on its own terms, ignoring prior steps."],"exploitation_risk":40,"canonical_source":{"authors":"Freedman, J. L., & Fraser, S. C.","year":1966,"title":"Compliance without Pressure: The Foot-in-the-Door Technique","venue":"Journal of Personality and Social Psychology, 4(2), 195-202","doi":"10.1037/h0023552"},"related_effects":["sunk-cost-fallacy","endowed-progress"]}],"total":36,"excluded_failed":12,"corpus_version":"2026-07"},"_meta":{"request_id":"req_f95f5ff9ca8947a2a51c918208025037","product":"psych/biases","version":"1.0.0","receipt_id":null,"cost":{"quoted":0,"charged":0,"currency":"USD","display":"0.000000"},"cache":{"hit":true,"age_s":41285},"provenance":{"sourcing_class":"B","upstream":["internal:psych-corpus@2026-07"],"fetched_at":"2026-10-13T11:53:06.089Z","license":"proprietary"},"freshness":{"as_of":"2026-07","staleness_s":41285},"confidence":1}}