{ "biases": [ { "slug": "anchoring", "name": "Anchoring", "family": "Anchoring", "evidence": "strong", "definition": "An initial number, even an irrelevant one, pulls later estimates towards it.", "psychology": "People rarely judge a number on its own terms. They start from whatever figure is in front of them and adjust, usually not far enough. In marketing, the first or largest number on screen sets the frame for everything after it.", "source": "Tversky & Kahneman (1974), Judgment under uncertainty: heuristics and biases.", "doi": [ "https://doi.org/10.1126/science.185.4157.1124" ], "url": "https://nudgeswipe.com/biases/anchoring/" }, { "slug": "reference-price", "name": "Reference price", "family": "Anchoring", "evidence": "strong", "definition": "A price is judged against a comparison price: a 'was' price, a monthly rate, a renewal rate.", "psychology": "Buyers judge a price as a gain or loss against the price they expect. A visible comparison price (a struck-through rate, a monthly equivalent) becomes that expectation. Unlike anchoring proper, the comparison is a real, relevant price.", "source": "Kalyanaram & Winer (1995), Empirical generalizations from reference price research.", "doi": [ "https://doi.org/10.1287/mksc.14.3.G161" ], "url": "https://nudgeswipe.com/biases/reference-price/" }, { "slug": "social-proof", "name": "Social proof", "family": "Social", "evidence": "strong", "definition": "When unsure, we look at what people like us do.", "psychology": "Descriptive norms (what most people do) shift behaviour, especially when the reference group feels similar. Logo strips, review counts and 'most popular' tags are commercial versions.", "source": "Goldstein, Cialdini & Griskevicius (2008), A room with a viewpoint.", "doi": [ "https://doi.org/10.1086/586910" ], "url": "https://nudgeswipe.com/biases/social-proof/" }, { "slug": "authority", "name": "Authority", "family": "Social", "evidence": "strong", "definition": "We defer to signals of expertise or official endorsement.", "psychology": "Cues of expertise (a 'Recommended' badge from the seller, an expert, a credential) lower the effort of deciding: someone who knows more has already chosen. The classic evidence comes from obedience studies; marketing uses mild versions.", "source": "Milgram (1963), Behavioral study of obedience.", "doi": [ "https://doi.org/10.1037/h0040525" ], "url": "https://nudgeswipe.com/biases/authority/" }, { "slug": "reciprocity", "name": "Reciprocity", "family": "Social", "evidence": "strong", "definition": "A favour received creates a felt obligation to return it.", "psychology": "Even a small unsolicited favour increases compliance with a later request, regardless of liking. Free tools, templates and samples work this way. It is strongest for unconditional gifts; a coupon that only pays out if you buy borrows the framing (mixed evidence).", "source": "Regan (1971), Effects of a favor and liking on compliance.", "doi": [ "https://doi.org/10.1016/0022-1031(71)90025-4" ], "url": "https://nudgeswipe.com/biases/reciprocity/" }, { "slug": "loss-aversion", "name": "Loss aversion", "family": "Risk", "evidence": "mixed", "definition": "Losses tend to loom larger than equivalent gains.", "psychology": "Framing an outcome as something you stand to lose (a streak, a discount) tends to motivate more than the same thing framed as a gain. How far this holds as a general law is debated, so treat it as a tendency, not a constant.", "source": "Kahneman & Tversky (1979), Prospect theory. Critique: Gal & Rucker (2018).", "doi": [ "https://doi.org/10.2307/1914185", "https://doi.org/10.1002/jcpy.1047" ], "url": "https://nudgeswipe.com/biases/loss-aversion/" }, { "slug": "regret-aversion", "name": "Regret aversion (risk reversal)", "family": "Risk", "evidence": "strong", "definition": "People avoid choices they expect to regret; removing the downside removes the regret.", "psychology": "Anticipated regret makes people delay or avoid decisions. A guarantee or long return window takes away the cost of being wrong. 'Risk reversal' is the marketing tactic; regret aversion is the bias underneath.", "source": "Simonson (1992), The influence of anticipating regret and responsibility on purchase decisions.", "doi": [ "https://doi.org/10.1086/209290" ], "url": "https://nudgeswipe.com/biases/regret-aversion/" }, { "slug": "endowment-effect", "name": "Endowment effect", "family": "Risk", "evidence": "strong", "definition": "We value things more once they feel like ours.", "psychology": "Owners demand more to give something up than buyers would pay for it. Trials, saved work and personalised setups can create a sense of ownership before purchase.", "source": "Kahneman, Knetsch & Thaler (1990), Experimental tests of the endowment effect.", "doi": [ "https://doi.org/10.1086/261737" ], "url": "https://nudgeswipe.com/biases/endowment-effect/" }, { "slug": "default-status-quo", "name": "Default effect / status quo bias", "family": "Choice architecture", "evidence": "strong", "definition": "People tend to stick with whatever is preselected or already happening.", "psychology": "Defaults carry effort, implied endorsement and inertia. Auto-renewal is the same family: the status quo continues unless you act.", "source": "Johnson & Goldstein (2003), Do defaults save lives? Meta-analysis: Jachimowicz et al. (2019). Status quo: Samuelson & Zeckhauser (1988).", "doi": [ "https://doi.org/10.1126/science.1091721", "https://doi.org/10.1017/bpp.2018.43" ], "url": "https://nudgeswipe.com/biases/default-status-quo/" }, { "slug": "choice-overload", "name": "Choice overload (simplification)", "family": "Choice architecture", "evidence": "mixed", "definition": "Too many options can stall a decision; simplifying can help.", "psychology": "Large assortments sometimes reduce purchase, but meta-analyses find the average effect is small and depends on context (complexity, clear preferences, time pressure).", "source": "Iyengar & Lepper (2000). Meta-analyses: Scheibehenne et al. (2010); Chernev et al. (2015).", "doi": [ "https://doi.org/10.1037/0022-3514.79.6.995", "https://doi.org/10.1016/j.jcps.2014.08.002" ], "url": "https://nudgeswipe.com/biases/choice-overload/" }, { "slug": "decoy-effect", "name": "Decoy effect", "family": "Choice architecture", "evidence": "mixed", "definition": "An inferior third option can make one of the other two look better.", "psychology": "An asymmetrically dominated option can shift choice towards its target, but the effect is weaker or absent when options are described pictorially or realistically.", "source": "Huber, Payne & Puto (1982). Limits: Frederick, Lee & Baskin (2014).", "doi": [ "https://doi.org/10.1086/208899", "https://doi.org/10.1509/jmr.12.0061" ], "url": "https://nudgeswipe.com/biases/decoy-effect/" }, { "slug": "zero-price-effect", "name": "Zero-price effect", "family": "Price", "evidence": "mixed", "definition": "'Free' is treated as more than just a lower price.", "psychology": "Moving a price to zero shifts choice more than an equal cut elsewhere. Evidence comes from a small number of mostly lab studies.", "source": "Shampanier, Mazar & Ariely (2007), Zero as a special price.", "doi": [ "https://doi.org/10.1287/mksc.1060.0254" ], "url": "https://nudgeswipe.com/biases/zero-price-effect/" }, { "slug": "price-framing", "name": "Price & attribute framing", "family": "Price", "evidence": "strong", "definition": "The same price or attribute feels different depending on how it's expressed.", "psychology": "Equivalent descriptions lead to different choices. A common pricing version is temporal framing: an annual price restated per week or per day feels smaller ('pennies-a-day').", "source": "Tversky & Kahneman (1981), The framing of decisions. Pennies-a-day: Gourville (1998).", "doi": [ "https://doi.org/10.1126/science.7455683", "https://doi.org/10.1086/209517" ], "url": "https://nudgeswipe.com/biases/price-framing/" }, { "slug": "mental-accounting", "name": "Mental accounting", "family": "Price", "evidence": "mixed", "definition": "People put money into mental buckets and treat it differently by bucket.", "psychology": "Credits, vouchers and 'savings' are spent differently from cash because they sit in different mental accounts. Field evidence on how reward labels are treated is thinner than the original theory.", "source": "Thaler (1985), Mental accounting and consumer choice. Also Thaler (1999), Mental accounting matters, https://doi.org/10.1002/(SICI)1099-0771(199909)12:3<183::AID-BDM318>3.0.CO;2-F", "doi": [ "https://doi.org/10.1287/mksc.4.3.199" ], "url": "https://nudgeswipe.com/biases/mental-accounting/" }, { "slug": "present-bias", "name": "Present bias", "family": "Time", "evidence": "strong", "definition": "Costs and rewards now weigh more than the same ones later.", "psychology": "People discount the future steeply in the short run, so '$1 now' or '£0 today' feels much more important than the later full price.", "source": "Laibson (1997), Golden eggs and hyperbolic discounting.", "doi": [ "https://doi.org/10.1162/003355397555253" ], "url": "https://nudgeswipe.com/biases/present-bias/" }, { "slug": "urgency", "name": "Urgency (deadline effect)", "family": "Time", "evidence": "strong", "definition": "A limited time to act prompts action now.", "psychology": "Deadlines stop people putting a decision off. Coupon research found more redemptions as the expiry date gets close, and people procrastinate more when there's no deadline. Urgency is about limited time; scarcity is about limited quantity.", "source": "Inman & McAlister (1994), Do coupon expiration dates affect consumer behavior? Also Shu & Gneezy (2010).", "doi": [ "https://doi.org/10.2307/3152229", "https://doi.org/10.1509/jmkr.47.5.933" ], "url": "https://nudgeswipe.com/biases/urgency/" }, { "slug": "scarcity", "name": "Scarcity", "family": "Time", "evidence": "mixed", "definition": "Things in limited quantity seem more valuable.", "psychology": "Items in short supply are rated as more desirable, especially when they become scarce. Effect sizes vary widely across studies. This is about quantity, not time.", "source": "Worchel, Lee & Adewole (1975), Effects of supply and demand on ratings of object value.", "doi": [ "https://doi.org/10.1037/0022-3514.32.5.906" ], "url": "https://nudgeswipe.com/biases/scarcity/" }, { "slug": "goal-gradient", "name": "Goal gradient (incl. endowed progress)", "family": "Motivation", "evidence": "strong", "definition": "Effort rises as people approach a goal, and a head start makes them more likely to finish.", "psychology": "Visible progress towards a reward accelerates effort near the end. Endowed progress, giving people a head start, also increases completion.", "source": "Kivetz, Urminsky & Zheng (2006). Endowed progress: Nunes & Drèze (2006).", "doi": [ "https://doi.org/10.1509/jmkr.43.1.39", "https://doi.org/10.1086/500480" ], "url": "https://nudgeswipe.com/biases/goal-gradient/" }, { "slug": "commitment-consistency", "name": "Commitment & consistency", "family": "Motivation", "evidence": "strong", "definition": "After a small commitment, people act to stay consistent with it.", "psychology": "Agreeing to a small request makes agreeing to a larger related one more likely (foot-in-the-door). Public or repeated commitments, like a streak, strengthen this.", "source": "Freedman & Fraser (1966), Compliance without pressure: the foot-in-the-door technique.", "doi": [ "https://doi.org/10.1037/h0023552" ], "url": "https://nudgeswipe.com/biases/commitment-consistency/" }, { "slug": "peak-end", "name": "Peak-end rule", "family": "Experience", "evidence": "strong", "definition": "Experiences are remembered by their peak and their ending.", "psychology": "People judge a past experience mostly by its most intense moment and how it ended, not its length. Onboarding, checkout and cancellation endings matter more than the middle.", "source": "Kahneman, Fredrickson, Schreiber & Redelmeier (1993), When more pain is preferred to less: adding a better end.", "doi": [ "https://doi.org/10.1111/j.1467-9280.1993.tb00589.x" ], "url": "https://nudgeswipe.com/biases/peak-end/" }, { "slug": "ikea-effect", "name": "IKEA effect", "family": "Experience", "evidence": "strong", "definition": "We value things more when we've helped make them.", "psychology": "People value products they assembled themselves more highly, provided they finish them.", "source": "Norton, Mochon & Ariely (2012), The IKEA effect: when labor leads to love.", "doi": [ "https://doi.org/10.1016/j.jcps.2011.08.002" ], "url": "https://nudgeswipe.com/biases/ikea-effect/" }, { "slug": "information-gap", "name": "Information gap (curiosity)", "family": "Experience", "evidence": "mixed", "definition": "A gap between what we know and want to know creates curiosity.", "psychology": "Curiosity rises when people notice a specific gap in their knowledge. In subject lines and headlines it can lift attention, but the evidence is mixed and it backfires when the payoff disappoints.", "source": "Loewenstein (1994), The psychology of curiosity.", "doi": [ "https://doi.org/10.1037/0033-2909.116.1.75" ], "url": "https://nudgeswipe.com/biases/information-gap/" }, { "slug": "friction", "name": "Friction (principle)", "family": "Principle", "evidence": "strong", "definition": "Not a bias: small hassles strongly change behaviour. Make the desired action easy.", "psychology": "The 'Easy' in the Behavioural Insights Team's EAST framework: removing steps and effort is often the strongest lever.", "source": "Behavioural Insights Team (2014), EAST: four simple ways to apply behavioural insights.", "doi": [ "https://www.bi.team/publications/east-four-simple-ways-to-apply-behavioural-insights/" ], "url": "https://nudgeswipe.com/biases/friction/" }, { "slug": "incentive", "name": "Incentive (principle)", "family": "Principle", "evidence": "strong", "definition": "Not a bias: a reward for doing something, such as a referral reward or sign-up discount.", "psychology": "Incentives change behaviour by paying for it. Referral rewards and sign-up or win-back discounts are incentives, because you only get them if you act. Reciprocity applies alongside only when one side receives a genuine, unconditional gift (for example, the friend in a give/get scheme). Referral-reward research finds that the size and split of the reward matter, especially between strong and weak ties.", "source": "Ryu & Feick (2007), A penny for your thoughts: referral reward programs and referral likelihood.", "doi": [ "https://doi.org/10.1509/jmkg.71.1.084" ], "url": "https://nudgeswipe.com/biases/incentive/" }, { "slug": "availability-heuristic", "name": "Availability heuristic", "family": "Judgement", "evidence": "strong", "definition": "We judge how likely or common something is by how easily examples come to mind.", "psychology": "Vivid stories, recent news and testimonials make outcomes feel more common than they are. Products show it in \"people like you just…\" feeds and case-study carousels.", "source": "Tversky & Kahneman (1973), Availability: A heuristic for judging frequency and probability.", "doi": [ "https://doi.org/10.1016/0010-0285(73)90033-9" ], "url": "https://nudgeswipe.com/biases/availability-heuristic/" }, { "slug": "confirmation-bias", "name": "Confirmation bias", "family": "Judgement", "evidence": "strong", "definition": "We look for, notice and remember evidence that fits what we already believe.", "psychology": "Users skim reviews and comparisons for support of the option they already lean towards; teams read A/B results the same way.", "source": "Wason (1960), On the Failure to Eliminate Hypotheses in a Conceptual Task.", "doi": [ "https://doi.org/10.1080/17470216008416717" ], "url": "https://nudgeswipe.com/biases/confirmation-bias/" }, { "slug": "overconfidence", "name": "Overconfidence", "family": "Judgement", "evidence": "strong", "definition": "We are more sure of our judgements than our accuracy justifies.", "psychology": "Customers overestimate how often they'll use a gym, a course or a subscription, so annual plans and long commitments look better than they turn out.", "source": "Fischhoff, Slovic & Lichtenstein (1977), Knowing with certainty: The appropriateness of extreme confidence.", "doi": [ "https://doi.org/10.1037/0096-1523.3.4.552" ], "url": "https://nudgeswipe.com/biases/overconfidence/" }, { "slug": "planning-fallacy", "name": "Planning fallacy", "family": "Judgement", "evidence": "strong", "definition": "We underestimate how long our own tasks will take, even when similar tasks ran late before.", "psychology": "Onboarding, setup and \"finish your profile\" flows feel quicker than they are, so people start and stall.", "source": "Buehler, Griffin & Ross (1994), Exploring the \"planning fallacy\": Why people underestimate their task completion times.", "doi": [ "https://doi.org/10.1037/0022-3514.67.3.366" ], "url": "https://nudgeswipe.com/biases/planning-fallacy/" }, { "slug": "optimism-bias", "name": "Optimism bias", "family": "Judgement", "evidence": "strong", "definition": "We think good things are more likely, and bad things less likely, to happen to us than to others.", "psychology": "People skip insurance, backups and cancellation planning because \"it won't happen to me\", and trust they'll remember to cancel a trial.", "source": "Weinstein (1980), Unrealistic optimism about future life events.", "doi": [ "https://doi.org/10.1037/0022-3514.39.5.806" ], "url": "https://nudgeswipe.com/biases/optimism-bias/" }, { "slug": "illusion-of-control", "name": "Illusion of control", "family": "Judgement", "evidence": "strong", "definition": "We overestimate how much we can influence outcomes that are largely down to chance.", "psychology": "Letting people pick numbers, spin, or \"choose your reward\" makes chance outcomes feel skill-based.", "source": "Langer (1975), The illusion of control.", "doi": [ "https://doi.org/10.1037/0022-3514.32.2.311" ], "url": "https://nudgeswipe.com/biases/illusion-of-control/" }, { "slug": "sunk-cost", "name": "Sunk cost effect", "family": "Risk", "evidence": "mixed", "definition": "We keep investing in something because of what we've already put in, not what we'll get.", "psychology": "Progress, streaks, saved data and \"you've already…\" messages make leaving feel like a waste of past effort.", "source": "Arkes & Blumer (1985), The psychology of sunk cost.", "doi": [ "https://doi.org/10.1016/0749-5978(85)90049-4" ], "url": "https://nudgeswipe.com/biases/sunk-cost/" }, { "slug": "certainty-effect", "name": "Certainty effect", "family": "Risk", "evidence": "strong", "definition": "We overweight outcomes that are certain compared with ones that are merely likely.", "psychology": "\"Guaranteed\", \"100% refund\" and \"you will get\" copy is worth more to people than a higher but uncertain payoff.", "source": "Kahneman & Tversky (1979), Prospect Theory: An Analysis of Decision under Risk.", "doi": [ "https://doi.org/10.2307/1914185" ], "url": "https://nudgeswipe.com/biases/certainty-effect/" }, { "slug": "ambiguity-aversion", "name": "Ambiguity aversion", "family": "Risk", "evidence": "strong", "definition": "We prefer known risks to unknown ones, even when the unknown might be better.", "psychology": "Unclear pricing, vague delivery dates and \"contact us\" plans put people off; clear numbers reassure.", "source": "Ellsberg (1961), Risk, Ambiguity, and the Savage Axioms.", "doi": [ "https://doi.org/10.2307/1884324" ], "url": "https://nudgeswipe.com/biases/ambiguity-aversion/" }, { "slug": "mere-exposure", "name": "Mere-exposure effect", "family": "Memory & attention", "evidence": "strong", "definition": "We tend to like things more the more often we've seen them.", "psychology": "Retargeting, repeated brand cues and consistent UI make a product feel familiar and trustworthy.", "source": "Zajonc (1968), Attitudinal effects of mere exposure.", "doi": [ "https://doi.org/10.1037/h0025848" ], "url": "https://nudgeswipe.com/biases/mere-exposure/" }, { "slug": "serial-position", "name": "Serial position effect", "family": "Memory & attention", "evidence": "strong", "definition": "We remember the first and last items in a list best.", "psychology": "The first and last plans, features or bullet points get the most attention; the middle blurs.", "source": "Murdock (1962), The serial position effect of free recall.", "doi": [ "https://doi.org/10.1037/h0045106" ], "url": "https://nudgeswipe.com/biases/serial-position/" }, { "slug": "von-restorff", "name": "Isolation (Von Restorff) effect", "family": "Memory & attention", "evidence": "strong", "definition": "An item that stands out from the rest is more likely to be noticed and remembered.", "psychology": "\"Most popular\" badges, a highlighted plan or a coloured button draw the eye in a row of similar items.", "source": "von Restorff (1933), Über die Wirkung von Bereichsbildungen im Spurenfeld.", "doi": [ "https://doi.org/10.1007/BF02409636" ], "url": "https://nudgeswipe.com/biases/von-restorff/" }, { "slug": "spacing-effect", "name": "Spacing effect", "family": "Principle", "evidence": "strong", "definition": "We remember better when practice is spread out over time rather than crammed.", "psychology": "Learning apps space reviews; drip onboarding emails introduce features over days rather than all at once.", "source": "Cepeda et al. (2006), Distributed practice in verbal recall tasks: A review and quantitative synthesis.", "doi": [ "https://doi.org/10.1037/0033-2909.132.3.354" ], "url": "https://nudgeswipe.com/biases/spacing-effect/" }, { "slug": "hicks-law", "name": "Hick's law", "family": "Principle", "evidence": "strong", "definition": "The time it takes to choose grows with the number and complexity of options.", "psychology": "Long menus, many plans and dense settings slow decisions; trimmed choices speed them.", "source": "Hick (1952), On the Rate of Gain of Information.", "doi": [ "https://doi.org/10.1080/17470215208416600" ], "url": "https://nudgeswipe.com/biases/hicks-law/" }, { "slug": "fitts-law", "name": "Fitts's law", "family": "Principle", "evidence": "strong", "definition": "The time to hit a target depends on its size and distance.", "psychology": "Big, close buttons get tapped; small, distant links get missed.", "source": "Fitts (1954), The information capacity of the human motor system in controlling the amplitude of movement.", "doi": [ "https://doi.org/10.1037/h0055392" ], "url": "https://nudgeswipe.com/biases/fitts-law/" }, { "slug": "working-memory-limits", "name": "Working-memory limits", "family": "Principle", "evidence": "strong", "definition": "We can hold only a few chunks of information in mind at once: about three to five, rather than Miller's often-quoted \"seven\".", "psychology": "Long codes, many plan details and multi-step instructions overload people; chunking helps.", "source": "Miller (1956), The magical number seven, plus or minus two: Some limits on our capacity for processing information.", "doi": [ "https://doi.org/10.1037/h0043158" ], "url": "https://nudgeswipe.com/biases/working-memory-limits/" }, { "slug": "cognitive-load", "name": "Cognitive load", "family": "Principle", "evidence": "strong", "definition": "Mental effort spent on processing a task leaves less capacity for learning or judging it.", "psychology": "Busy pages, jargon and many fields make people give up or default to the easiest option.", "source": "Sweller (1988), Cognitive Load During Problem Solving: Effects on Learning.", "doi": [ "https://doi.org/10.1207/s15516709cog1202_4" ], "url": "https://nudgeswipe.com/biases/cognitive-load/" }, { "slug": "change-blindness", "name": "Change blindness", "family": "Memory & attention", "evidence": "strong", "definition": "We often fail to notice large changes to a scene, especially across a break or page load.", "psychology": "Prices or terms that change between steps of a checkout often go unnoticed.", "source": "Simons & Levin (1997), Change blindness.", "doi": [ "https://doi.org/10.1016/S1364-6613(97)01080-2" ], "url": "https://nudgeswipe.com/biases/change-blindness/" }, { "slug": "inattentional-blindness", "name": "Inattentional blindness", "family": "Memory & attention", "evidence": "strong", "definition": "When focused on one thing, we can miss something unexpected in plain sight.", "psychology": "Users focused on a task miss banners, notices and side panels.", "source": "Simons & Chabris (1999), Gorillas in Our Midst: Sustained Inattentional Blindness for Dynamic Events.", "doi": [ "https://doi.org/10.1068/p281059" ], "url": "https://nudgeswipe.com/biases/inattentional-blindness/" }, { "slug": "aesthetic-usability", "name": "Aesthetic-usability effect", "family": "Experience", "evidence": "limited", "definition": "We perceive attractive designs as easier to use.", "psychology": "Polished visuals make people more forgiving of usability problems and more trusting of a product.", "source": "Kurosu & Kashimura (1995), Apparent usability vs. inherent usability.", "doi": [ "https://doi.org/10.1145/223355.223680" ], "url": "https://nudgeswipe.com/biases/aesthetic-usability/" }, { "slug": "processing-fluency", "name": "Processing fluency", "family": "Memory & attention", "evidence": "strong", "definition": "Information that's easy to process feels more true, likeable and familiar.", "psychology": "Clear fonts, simple names and plain copy make claims feel more credible.", "source": "Reber & Schwarz (1999), Effects of Perceptual Fluency on Judgments of Truth.", "doi": [ "https://doi.org/10.1006/ccog.1999.0386" ], "url": "https://nudgeswipe.com/biases/processing-fluency/" }, { "slug": "labor-illusion", "name": "Labour illusion", "family": "Experience", "evidence": "limited", "definition": "We value a service more when we can see the effort that goes into it.", "psychology": "\"Searching 400 airlines…\" progress screens make results feel more valuable than an instant answer.", "source": "Buell & Norton (2011), The Labor Illusion: How Operational Transparency Increases Perceived Value.", "doi": [ "https://doi.org/10.1287/mnsc.1110.1376" ], "url": "https://nudgeswipe.com/biases/labor-illusion/" }, { "slug": "pratfall-effect", "name": "Pratfall effect", "family": "Social", "evidence": "limited", "definition": "A small blunder can make a highly competent person more likeable.", "psychology": "Brands that admit a minor flaw (\"we're not the cheapest\") can seem more trustworthy.", "source": "Aronson, Willerman & Floyd (1966), The effect of a pratfall on increasing interpersonal attractiveness.", "doi": [ "https://doi.org/10.3758/BF03342263" ], "url": "https://nudgeswipe.com/biases/pratfall-effect/" }, { "slug": "halo-effect", "name": "Halo effect", "family": "Social", "evidence": "strong", "definition": "One positive trait colours our judgement of unrelated traits.", "psychology": "A beautiful design, a celebrity or an award makes people assume the product is good in other ways too.", "source": "Nisbett & Wilson (1977), The halo effect: Evidence for unconscious alteration of judgments.", "doi": [ "https://doi.org/10.1037/0022-3514.35.4.250" ], "url": "https://nudgeswipe.com/biases/halo-effect/" }, { "slug": "conformity", "name": "Conformity", "family": "Social", "evidence": "strong", "definition": "Under direct group pressure we may go along with a majority, even against what we can see is true (Asch-style conformity).", "psychology": "Distinct from social proof (copying others when unsure): conformity is giving in to a visible majority when you're not unsure. In products it shows up in live group settings, e.g. team votes and public polls where everyone sees how others voted.", "source": "Asch (1956), Studies of independence and conformity: I. A minority of one against a unanimous majority.", "doi": [ "https://doi.org/10.1037/h0093718" ], "url": "https://nudgeswipe.com/biases/conformity/" }, { "slug": "in-group-bias", "name": "In-group bias", "family": "Social", "evidence": "strong", "definition": "We favour people who belong to our own group, even when the groups are trivially defined.", "psychology": "Community labels (\"for designers\", member clubs) make offers feel like they're for \"people like us\".", "source": "Tajfel et al. (1971), Social categorization and intergroup behaviour.", "doi": [ "https://doi.org/10.1002/ejsp.2420010202" ], "url": "https://nudgeswipe.com/biases/in-group-bias/" }, { "slug": "similarity-liking", "name": "Similarity–liking", "family": "Social", "evidence": "strong", "definition": "We like people who are similar to us, including in their attitudes.", "psychology": "Testimonials and reps that match the customer's situation feel more persuasive.", "source": "Byrne (1961), Interpersonal attraction and attitude similarity.", "doi": [ "https://doi.org/10.1037/h0044721" ], "url": "https://nudgeswipe.com/biases/similarity-liking/" }, { "slug": "door-in-the-face", "name": "Door-in-the-face", "family": "Technique", "evidence": "strong", "definition": "After refusing a big request, we're more likely to agree to a smaller one.", "psychology": "Showing a premium plan first, then a \"lighter\" option, or a big donation ask followed by a smaller one.", "source": "Cialdini et al. (1975), Reciprocal concessions procedure for inducing compliance: The door-in-the-face technique.", "doi": [ "https://doi.org/10.1037/h0076284" ], "url": "https://nudgeswipe.com/biases/door-in-the-face/" }, { "slug": "thats-not-all", "name": "That's-not-all technique", "family": "Technique", "evidence": "strong", "definition": "Adding a bonus or discount before the person responds makes them more likely to accept.", "psychology": "\"But wait, we'll also add…\" bonuses in sales pages and checkout.", "source": "Burger (1986), Increasing compliance by improving the deal: The that's-not-all technique.", "doi": [ "https://doi.org/10.1037/0022-3514.51.2.277" ], "url": "https://nudgeswipe.com/biases/thats-not-all/" }, { "slug": "low-ball", "name": "Low-ball technique", "family": "Technique", "evidence": "strong", "definition": "Once committed to a deal, we often accept it even when the cost goes up.", "psychology": "A low headline price, then fees and add-ons at checkout after the decision is made.", "source": "Cialdini et al. (1978), Low-ball procedure for producing compliance: Commitment then cost.", "doi": [ "https://doi.org/10.1037/0022-3514.36.5.463" ], "url": "https://nudgeswipe.com/biases/low-ball/" }, { "slug": "reason-giving", "name": "Reason-giving (\"because\")", "family": "Technique", "evidence": "limited", "definition": "Requests that come with a reason are more often granted, even when the reason is thin.", "psychology": "\"Because\" explanations (\"we ask for your phone because…\") increase compliance.", "source": "Langer, Blank & Chanowitz (1978), The mindlessness of ostensibly thoughtful action: The role of \"placebic\" information in interpersonal interaction.", "doi": [ "https://doi.org/10.1037/0022-3514.36.6.635" ], "url": "https://nudgeswipe.com/biases/reason-giving/" }, { "slug": "reactance", "name": "Reactance", "family": "Social", "evidence": "strong", "definition": "When we feel our freedom is threatened, we push back and want the restricted thing more.", "psychology": "Hard-sell pop-ups and forced choices can backfire; \"you choose\" framing reduces pushback.", "source": "Clee & Wicklund (1980), Consumer Behavior and Psychological Reactance.", "doi": [ "https://doi.org/10.1086/208782" ], "url": "https://nudgeswipe.com/biases/reactance/" }, { "slug": "curse-of-knowledge", "name": "Curse of knowledge", "family": "Judgement", "evidence": "limited", "definition": "Once we know something, it's hard to imagine not knowing it.", "psychology": "Teams write onboarding and pricing pages full of jargon that new users don't understand.", "source": "Camerer, Loewenstein & Weber (1989), The Curse of Knowledge in Economic Settings: An Experimental Analysis.", "doi": [ "https://doi.org/10.1086/261651" ], "url": "https://nudgeswipe.com/biases/curse-of-knowledge/" }, { "slug": "dunning-kruger", "name": "Dunning–Kruger effect", "family": "Judgement", "evidence": "mixed", "definition": "People with low skill in an area tend to overestimate their ability.", "psychology": "Users rate their own expertise and pick advanced options they're not ready for.", "source": "Kruger & Dunning (1999), Unskilled and unaware of it: How difficulties in recognizing one's own incompetence lead to inflated self-assessments.", "doi": [ "https://doi.org/10.1037/0022-3514.77.6.1121" ], "url": "https://nudgeswipe.com/biases/dunning-kruger/" }, { "slug": "choice-supportive-bias", "name": "Choice-supportive bias", "family": "Judgement", "evidence": "limited", "definition": "After choosing, we remember the chosen option as better than it was.", "psychology": "Post-purchase emails that reinforce the choice (\"great pick\") keep people satisfied.", "source": "Mather & Johnson (2000), Choice-supportive source monitoring: Do our decisions seem better to us as we age?.", "doi": [ "https://doi.org/10.1037/0882-7974.15.4.596" ], "url": "https://nudgeswipe.com/biases/choice-supportive-bias/" }, { "slug": "cognitive-dissonance", "name": "Cognitive dissonance", "family": "Judgement", "evidence": "mixed", "definition": "Holding conflicting beliefs or actions is uncomfortable, so we adjust our attitudes to fit what we did.", "psychology": "After paying or committing, people justify the choice and become more loyal.", "source": "Festinger & Carlsmith (1959), Cognitive consequences of forced compliance.", "doi": [ "https://doi.org/10.1037/h0041593" ], "url": "https://nudgeswipe.com/biases/cognitive-dissonance/" }, { "slug": "effort-justification", "name": "Effort justification", "family": "Experience", "evidence": "limited", "definition": "We value things more when we've worked or suffered to get them.", "psychology": "Applications, waitlists and challenges make membership feel more valuable.", "source": "Aronson & Mills (1959), The effect of severity of initiation on liking for a group.", "doi": [ "https://doi.org/10.1037/h0047195" ], "url": "https://nudgeswipe.com/biases/effort-justification/" }, { "slug": "pain-of-paying", "name": "Pain of paying", "family": "Price", "evidence": "strong", "definition": "Paying feels unpleasant, and that pain depends on how and when we pay.", "psychology": "Prepaid plans, saved cards and one-click buy make payment feel lighter.", "source": "Prelec & Loewenstein (1998), The Red and the Black: Mental Accounting of Savings and Debt.", "doi": [ "https://doi.org/10.1287/mksc.17.1.4" ], "url": "https://nudgeswipe.com/biases/pain-of-paying/" }, { "slug": "credit-card-premium", "name": "Credit-card premium", "family": "Price", "evidence": "limited", "definition": "People may be willing to pay more when using a card than cash.", "psychology": "Card-on-file and digital wallets make spending feel abstract.", "source": "Prelec & Simester (2001), Always Leave Home Without It: A Further Investigation of the Credit-Card Effect on Willingness to Pay.", "doi": [ "https://doi.org/10.1023/A:1008196717017" ], "url": "https://nudgeswipe.com/biases/credit-card-premium/" }, { "slug": "left-digit-effect", "name": "Left-digit effect", "family": "Price", "evidence": "strong", "definition": "We judge prices largely by their first digit, so £2.99 feels much cheaper than £3.00.", "psychology": "Charm prices ending in .99 or .95 are common across retail and subscriptions.", "source": "Thomas & Morwitz (2005), Penny Wise and Pound Foolish: The Left‐Digit Effect in Price Cognition.", "doi": [ "https://doi.org/10.1086/429600" ], "url": "https://nudgeswipe.com/biases/left-digit-effect/" }, { "slug": "price-quality-heuristic", "name": "Price-quality heuristic", "family": "Price", "evidence": "limited", "definition": "We use price as a cue to quality, and a higher price can even make something taste better to us.", "psychology": "Premium pricing signals quality; discounts can make products feel lesser.", "source": "Plassmann et al. (2008), Marketing actions can modulate neural representations of experienced pleasantness.", "doi": [ "https://doi.org/10.1073/pnas.0706929105" ], "url": "https://nudgeswipe.com/biases/price-quality-heuristic/" }, { "slug": "compromise-effect", "name": "Compromise effect", "family": "Choice architecture", "evidence": "mixed", "definition": "We favour the middle option when choices range from low to high.", "psychology": "Three-tier pricing pages where the middle tier is the target.", "source": "Simonson (1989), Choice Based on Reasons: The Case of Attraction and Compromise Effects.", "doi": [ "https://doi.org/10.1086/209205" ], "url": "https://nudgeswipe.com/biases/compromise-effect/" }, { "slug": "partitioned-pricing", "name": "Partitioned pricing", "family": "Technique", "evidence": "strong", "definition": "Splitting a price into a base price plus surcharges can make the total seem lower.", "psychology": "Base price plus shipping, service or booking fees.", "source": "Morwitz, Greenleaf & Johnson (1998), Divide and Prosper: Consumers' Reactions to Partitioned Prices.", "doi": [ "https://doi.org/10.2307/3152164" ], "url": "https://nudgeswipe.com/biases/partitioned-pricing/" }, { "slug": "denomination-effect", "name": "Denomination effect", "family": "Price", "evidence": "limited", "definition": "We are less likely to spend money held in a large denomination than the same amount in smaller units.", "psychology": "Credits, points and small top-ups feel easier to spend than a large balance.", "source": "Raghubir & Srivastava (2009), The Denomination Effect.", "doi": [ "https://doi.org/10.1086/599222" ], "url": "https://nudgeswipe.com/biases/denomination-effect/" }, { "slug": "fresh-start-effect", "name": "Fresh start effect", "family": "Motivation", "evidence": "limited", "definition": "Temporal landmarks like New Year, a birthday or a Monday make us more likely to pursue goals.", "psychology": "Campaigns timed to January, Mondays or the start of a month.", "source": "Dai, Milkman & Riis (2014), The Fresh Start Effect: Temporal Landmarks Motivate Aspirational Behavior.", "doi": [ "https://doi.org/10.1287/mnsc.2014.1901" ], "url": "https://nudgeswipe.com/biases/fresh-start-effect/" }, { "slug": "implementation-intentions", "name": "Implementation intentions", "family": "Technique", "evidence": "strong", "definition": "Planning exactly when, where and how we'll act makes us more likely to follow through.", "psychology": "\"When do you want to practise?\" schedulers and calendar prompts.", "source": "Gollwitzer (1999), Implementation intentions: Strong effects of simple plans.", "doi": [ "https://doi.org/10.1037/0003-066X.54.7.493" ], "url": "https://nudgeswipe.com/biases/implementation-intentions/" }, { "slug": "temptation-bundling", "name": "Temptation bundling", "family": "Technique", "evidence": "limited", "definition": "Pairing something we should do with something we want to do helps us do the first.", "psychology": "Audiobooks only at the gym, rewards attached to habits.", "source": "Milkman, Minson & Volpp (2014), Holding the Hunger Games Hostage at the Gym: An Evaluation of Temptation Bundling.", "doi": [ "https://doi.org/10.1287/mnsc.2013.1784" ], "url": "https://nudgeswipe.com/biases/temptation-bundling/" }, { "slug": "overjustification", "name": "Overjustification effect", "family": "Motivation", "evidence": "mixed", "definition": "External rewards can reduce our intrinsic motivation for an activity we already enjoyed.", "psychology": "Points and badges for things people did for fun can make them stop when rewards end.", "source": "Lepper, Greene & Nisbett (1973), Undermining children's intrinsic interest with extrinsic reward: A test of the \"overjustification\" hypothesis.", "doi": [ "https://doi.org/10.1037/h0035519" ], "url": "https://nudgeswipe.com/biases/overjustification/" }, { "slug": "licensing-effect", "name": "Licensing effect", "family": "Self & identity", "evidence": "mixed", "definition": "After doing something good, we feel licensed to indulge or behave less well.", "psychology": "Eco or health \"points\" can be followed by indulgent purchases.", "source": "Khan & Dhar (2006), Licensing Effect in Consumer Choice.", "doi": [ "https://doi.org/10.1509/jmkr.43.2.259" ], "url": "https://nudgeswipe.com/biases/licensing-effect/" }, { "slug": "identity-labelling", "name": "Identity labelling", "family": "Self & identity", "evidence": "mixed", "definition": "Describing a behaviour as part of who we are (\"be a voter\") can motivate it.", "psychology": "\"Join the readers who…\", \"become a member\" copy.", "source": "Bryan et al. (2011), Motivating voter turnout by invoking the self.", "doi": [ "https://doi.org/10.1073/pnas.1103343108" ], "url": "https://nudgeswipe.com/biases/identity-labelling/" }, { "slug": "choice-blindness", "name": "Choice blindness", "family": "Judgement", "evidence": "limited", "definition": "We can fail to notice when what we get is not what we chose, and still justify it.", "psychology": "Swapped options at checkout or changed defaults may not be noticed.", "source": "Johansson et al. (2005), Failure to Detect Mismatches Between Intention and Outcome in a Simple Decision Task.", "doi": [ "https://doi.org/10.1126/science.1111709" ], "url": "https://nudgeswipe.com/biases/choice-blindness/" }, { "slug": "affect-heuristic", "name": "Affect heuristic", "family": "Judgement", "evidence": "strong", "definition": "Our feelings about something shape our judgement of its risks and benefits.", "psychology": "Warm imagery makes a product feel low-risk and high-benefit.", "source": "Finucane et al. (2000), The affect heuristic in judgments of risks and benefits.", "doi": [ "https://doi.org/10.1002/(SICI)1099-0771(200001/03)13:1<1::AID-BDM333>3.0.CO;2-S" ], "url": "https://nudgeswipe.com/biases/affect-heuristic/" }, { "slug": "identifiable-victim", "name": "Identifiable victim effect", "family": "Social", "evidence": "mixed", "definition": "We tend to help one named person more than many statistical victims.", "psychology": "Charities and campaigns lead with one person's story.", "source": "Small, Loewenstein & Slovic (2007), Sympathy and callousness: The impact of deliberative thought on donations to identifiable and statistical victims.", "doi": [ "https://doi.org/10.1016/j.obhdp.2006.01.005" ], "url": "https://nudgeswipe.com/biases/identifiable-victim/" }, { "slug": "hot-cold-empathy-gap", "name": "Hot–cold empathy gap", "family": "Time", "evidence": "strong", "definition": "In a calm state we underestimate how much hunger, anger or desire will change our choices, and vice versa.", "psychology": "Late-night shopping, hungry-hour food delivery promos.", "source": "Loewenstein (2005), Hot-cold empathy gaps and medical decision making.", "doi": [ "https://doi.org/10.1037/0278-6133.24.4.S49" ], "url": "https://nudgeswipe.com/biases/hot-cold-empathy-gap/" }, { "slug": "projection-bias", "name": "Projection bias", "family": "Time", "evidence": "limited", "definition": "We assume our future preferences will match our current ones.", "psychology": "People buy subscriptions or gear based on today's enthusiasm.", "source": "Loewenstein, O'Donoghue & Rabin (2003), Projection Bias in Predicting Future Utility.", "doi": [ "https://doi.org/10.1162/003355303322552784" ], "url": "https://nudgeswipe.com/biases/projection-bias/" }, { "slug": "diversification-bias", "name": "Diversification bias", "family": "Choice architecture", "evidence": "strong", "definition": "When choosing several items at once, we pick more variety than we'll actually want.", "psychology": "Bundle builders and \"mix your box\" offers.", "source": "Read & Loewenstein (1995), Diversification bias: Explaining the discrepancy in variety seeking between combined and separated choices.", "doi": [ "https://doi.org/10.1037/1076-898X.1.1.34" ], "url": "https://nudgeswipe.com/biases/diversification-bias/" }, { "slug": "focusing-illusion", "name": "Focusing illusion", "family": "Judgement", "evidence": "limited", "definition": "Whatever we focus on seems more important than it is.", "psychology": "Feature-focused ads make one attribute seem decisive.", "source": "Schkade & Kahneman (1998), Does Living in California Make People Happy? A Focusing Illusion in Judgments of Life Satisfaction.", "doi": [ "https://doi.org/10.1111/1467-9280.00066" ], "url": "https://nudgeswipe.com/biases/focusing-illusion/" }, { "slug": "negativity-bias", "name": "Negativity bias", "family": "Risk", "evidence": "strong", "definition": "Bad events and information affect us more than equally good ones.", "psychology": "Negative reviews and warnings carry more weight than praise.", "source": "Baumeister et al. (2001), Bad is Stronger than Good.", "doi": [ "https://doi.org/10.1037/1089-2680.5.4.323" ], "url": "https://nudgeswipe.com/biases/negativity-bias/" }, { "slug": "distinction-bias", "name": "Distinction bias", "family": "Choice architecture", "evidence": "limited", "definition": "Comparing options side by side makes small differences seem bigger than they will feel in use.", "psychology": "Spec comparison tables exaggerate minor differences.", "source": "Hsee & Zhang (2004), Distinction Bias: Misprediction and Mischoice Due to Joint Evaluation.", "doi": [ "https://doi.org/10.1037/0022-3514.86.5.680" ], "url": "https://nudgeswipe.com/biases/distinction-bias/" }, { "slug": "less-is-better", "name": "Less-is-better effect", "family": "Choice architecture", "evidence": "limited", "definition": "A lower-value option can be valued more when judged alone than a higher-value one.", "psychology": "A full small box can seem better than a half-full large one.", "source": "Hsee (1998), Less is better: when low-value options are valued more highly than high-value options.", "doi": [ "https://doi.org/10.1002/(SICI)1099-0771(199806)11:2<107::AID-BDM292>3.0.CO;2-Y" ], "url": "https://nudgeswipe.com/biases/less-is-better/" }, { "slug": "unit-bias", "name": "Unit bias", "family": "Choice architecture", "evidence": "limited", "definition": "We treat one unit as the right amount, whatever its size.", "psychology": "Portion and package size shape consumption.", "source": "Geier, Rozin & Doros (2006), Unit Bias.", "doi": [ "https://doi.org/10.1111/j.1467-9280.2006.01738.x" ], "url": "https://nudgeswipe.com/biases/unit-bias/" }, { "slug": "ostrich-effect", "name": "Ostrich effect", "family": "Risk", "evidence": "limited", "definition": "We avoid information we expect to be unpleasant.", "psychology": "People avoid checking account balances or usage.", "source": "Karlsson, Loewenstein & Seppi (2009), The ostrich effect: Selective attention to information.", "doi": [ "https://doi.org/10.1007/s11166-009-9060-6" ], "url": "https://nudgeswipe.com/biases/ostrich-effect/" }, { "slug": "barnum-effect", "name": "Barnum effect", "family": "Self & identity", "evidence": "strong", "definition": "We accept vague, general descriptions as accurate about ourselves.", "psychology": "Personality quizzes and \"your type\" results.", "source": "Forer (1949), The fallacy of personal validation: a classroom demonstration of gullibility.", "doi": [ "https://doi.org/10.1037/h0059240" ], "url": "https://nudgeswipe.com/biases/barnum-effect/" }, { "slug": "illusory-truth", "name": "Illusory truth effect", "family": "Memory & attention", "evidence": "strong", "definition": "Repeated statements feel more true, whether or not they are.", "psychology": "Repeated slogans and claims become believable.", "source": "Hasher, Goldstein & Toppino (1977), Frequency and the conference of referential validity.", "doi": [ "https://doi.org/10.1016/S0022-5371(77)80012-1" ], "url": "https://nudgeswipe.com/biases/illusory-truth/" }, { "slug": "marketing-placebo", "name": "Marketing placebo effect", "family": "Price", "evidence": "limited", "definition": "Marketing such as price can change how well a product actually works for us.", "psychology": "Discounted products may be experienced as less effective.", "source": "Shiv, Carmon & Ariely (2005), Placebo Effects of Marketing Actions: Consumers May Get What They Pay For.", "doi": [ "https://doi.org/10.1509/jmkr.2005.42.4.383" ], "url": "https://nudgeswipe.com/biases/marketing-placebo/" }, { "slug": "scope-insensitivity", "name": "Scope insensitivity", "family": "Judgement", "evidence": "limited", "definition": "Our willingness to pay or help barely changes with the size of the problem.", "psychology": "Donation and offset asks barely change with the scale shown.", "source": "Kahneman & Knetsch (1992), Valuing public goods: The purchase of moral satisfaction.", "doi": [ "https://doi.org/10.1016/0095-0696(92)90019-S" ], "url": "https://nudgeswipe.com/biases/scope-insensitivity/" }, { "slug": "rhyme-as-reason", "name": "Rhyme-as-reason effect", "family": "Memory & attention", "evidence": "limited", "definition": "Rhyming statements can seem more accurate than non-rhyming ones.", "psychology": "Slogans that rhyme stick and persuade.", "source": "McGlone & Tofighbakhsh (2000), Birds of a Feather Flock Conjointly (?): Rhyme as Reason in Aphorisms.", "doi": [ "https://doi.org/10.1111/1467-9280.00282" ], "url": "https://nudgeswipe.com/biases/rhyme-as-reason/" }, { "slug": "self-reference-effect", "name": "Self-reference effect", "family": "Self & identity", "evidence": "strong", "definition": "We remember information better when it relates to ourselves.", "psychology": "Personalised copy (\"your plan\", \"your savings\").", "source": "Rogers, Kuiper & Kirker (1977), Self-reference and the encoding of personal information.", "doi": [ "https://doi.org/10.1037/0022-3514.35.9.677" ], "url": "https://nudgeswipe.com/biases/self-reference-effect/" }, { "slug": "name-letter-effect", "name": "Name-letter effect", "family": "Self & identity", "evidence": "limited", "definition": "We tend to prefer the letters in our own name.", "psychology": "Personalised names in emails and products.", "source": "Nuttin (1985), Narcissism beyond Gestalt and awareness: The name letter effect.", "doi": [ "https://doi.org/10.1002/ejsp.2420150309" ], "url": "https://nudgeswipe.com/biases/name-letter-effect/" }, { "slug": "social-comparison", "name": "Social comparison", "family": "Social", "evidence": "strong", "definition": "We evaluate ourselves by comparing with others.", "psychology": "Leaderboards and \"you're ahead of 80% of users\" messages.", "source": "Festinger (1954), A Theory of Social Comparison Processes.", "doi": [ "https://doi.org/10.1177/001872675400700202" ], "url": "https://nudgeswipe.com/biases/social-comparison/" }, { "slug": "mere-measurement", "name": "Mere-measurement effect", "family": "Technique", "evidence": "limited", "definition": "Being asked about our intentions can change our behaviour.", "psychology": "Surveys asking \"do you plan to buy?\" can raise purchases.", "source": "Morwitz, Johnson & Schmittlein (1993), Does Measuring Intent Change Behavior?.", "doi": [ "https://doi.org/10.1086/209332" ], "url": "https://nudgeswipe.com/biases/mere-measurement/" } ] }