# Nudgeswipe

> Annotated teardowns of real products and marketing (pricing pages, paywalls, onboarding, homepages, emails), each tagged with the behavioural bias it uses, the psychology behind it, how to apply it, and an ethics watch-out. Sources are linked and dated. Outcomes are not public unless stated.

120 teardowns and 95 biases. Every bias page gives a plain definition, the original study, an evidence rating (strong, mixed or limited), the honest use and the dark-pattern line. Every teardown says what the brand did, which bias it uses, why it nudges, what to copy and what to watch out for.

How to cite: say a brand *uses* a tactic; Nudgeswipe does not claim it worked. Results are not public unless a teardown links a source. Please credit Nudgeswipe and keep the source links.

## Key pages
- [Teardown library](https://nudgeswipe.com/#library)
- [Bias directory](https://nudgeswipe.com/biases/)
- [About and methods](https://nudgeswipe.com/about/)
- [Advertise (newsletter sponsorship, founding rates)](https://nudgeswipe.com/advertise/)
- [Full text for LLMs](https://nudgeswipe.com/llms-full.txt)

## Agent access
- MCP server (Streamable HTTP, read-only, no auth): https://nudgeswipe.com/api/mcp. Tools: search_teardowns, get_teardown, list_biases, get_bias
- JSON: https://nudgeswipe.com/api/teardowns.json, https://nudgeswipe.com/api/biases.json, https://nudgeswipe.com/api/teardowns/{slug}.json

## Teardowns
- [The Economist prices a year by the week, and preselects it](https://nudgeswipe.com/examples/economist-per-week-price-preselected-annual/): The Economist, Pricing, Price & attribute framing
- [Nuts.com counts the deadline down in the subject line](https://nudgeswipe.com/examples/nuts-com-deadline-countdown-emails/): Nuts.com, Email, Urgency (deadline effect)
- [Lacoste turns a points multiplier into a weekend deadline](https://nudgeswipe.com/examples/lacoste-members-week-triple-points-email/): Lacoste, Email, Urgency (deadline effect)
- [Duolingo explains its own streak in behavioural terms](https://nudgeswipe.com/examples/duolingo-streak-loss-aversion/): Duolingo, Product / retention, Loss aversion
- [LinkedIn turns profile completion into a meter](https://nudgeswipe.com/examples/linkedin-profile-strength-meter/): LinkedIn, Onboarding, Goal gradient (incl. endowed progress)
- [Slack shows the full price struck through next to the intro price](https://nudgeswipe.com/examples/slack-strikethrough-intro-price/): Slack, Pricing, Reference price
- [Notion labels one plan "Recommended" and leads with logos](https://nudgeswipe.com/examples/notion-recommended-business-plan/): Notion, Pricing, Authority
- [Mailchimp preselects a free trial of its Standard plan](https://nudgeswipe.com/examples/mailchimp-preselected-free-trial/): Mailchimp, Pricing, Default effect / status quo bias
- [Spotify leads with "£0" and spells out the price after](https://nudgeswipe.com/examples/spotify-two-months-for-zero/): Spotify, Pricing, Zero-price effect
- [Shopify makes starting cost $1 a month](https://nudgeswipe.com/examples/shopify-one-dollar-intro/): Shopify, Pricing, Present bias
- [Apple anchors trade-in value at the top of a range](https://nudgeswipe.com/examples/apple-trade-in-upper-bound/): Apple, Product page, Anchoring
- [IKEA takes the regret out of buying furniture](https://nudgeswipe.com/examples/ikea-365-day-returns/): IKEA, Checkout / policy, Regret aversion (risk reversal)
- [DIFF gives the abandoned cart two one-click routes back to checkout](https://nudgeswipe.com/examples/diff-eyewear-cart-misses-you/): DIFF Eyewear, Email, Friction (principle)
- [The North Face keeps its abandoned-cart email to one job](https://nudgeswipe.com/examples/the-north-face-cart-today-outdoors-tomorrow/): The North Face, Email, Friction (principle)
- [Evelyn & Bobbie sends the abandoned cart from a named fit expert](https://nudgeswipe.com/examples/evelyn-bobbie-fit-expert-cart-email/): Evelyn & Bobbie, Email, Authority
- [DELTA's welcome email leads with 100,000 customers](https://nudgeswipe.com/examples/delta-welcome-100000-customers/): DELTA, Email, Social proof
- [Flow frames its welcome discount as a thank-you](https://nudgeswipe.com/examples/flow-welcome-thanks-discount/): Flow, Email, Reciprocity
- [Sharper Image calls its restocked weather station a bestseller](https://nudgeswipe.com/examples/sharper-image-back-in-stock-bestseller/): Sharper Image, Email, Social proof
- [Tea Forté makes referral a two-way gift, and offers a snooze](https://nudgeswipe.com/examples/tea-forte-give-20-get-20/): Tea Forté, Email, Incentive (principle)
- [Nanit gives the friend five times what the referrer gets](https://nudgeswipe.com/examples/nanit-referral-friend-gets-more/): Nanit, Email, Incentive (principle)
- [RSPCA asks for 2 minutes, then offers a bigger ask](https://nudgeswipe.com/examples/rspca-two-minutes-then-do-more/): RSPCA, Email, Commitment & consistency
- [Dorai puts the deadline in three words and the exact cut-off in the small print](https://nudgeswipe.com/examples/dorai-sale-ends-tonight-did-you-shop/): Dorai Home, Email, Urgency (deadline effect)
- [Calm's trial email states the renewal date, price and how to cancel](https://nudgeswipe.com/examples/calm-trial-start-renewal-disclosure/): Calm, Email, Default effect / status quo bias
- [Calm ends a cancelled trial without guilt or a hard sell](https://nudgeswipe.com/examples/calm-trial-cancelled-graceful-ending/): Calm, Email, Peak-end rule
- [Uniqlo's win-back gives a $10 voucher with a $100 threshold](https://nudgeswipe.com/examples/uniqlo-hello-again-win-back/): Uniqlo, Email, Incentive (principle)
- [MORI points lapsed parents to "where most parents start"](https://nudgeswipe.com/examples/mori-where-most-parents-start/): MORI, Email, Social proof
- [OFFICE sells trainers with customers' own outfits](https://nudgeswipe.com/examples/office-fits-of-the-season-ugc/): OFFICE, Email, Social proof
- [Sakuto opens a question in the subject line and answers it in the first line](https://nudgeswipe.com/examples/sakuto-ever-wondered-damascus/): Sakuto Knives, Email, Information gap (curiosity)
- [Rest turns choosing bedding into a series of two-option questions](https://nudgeswipe.com/examples/rest-this-bed-or-that-bed-quiz/): Rest, Email, Choice overload (simplification)
- [Musicbed values its free trial at $177 and explains the renewal](https://nudgeswipe.com/examples/musicbed-177-worth-free-trial/): Musicbed, Email, Zero-price effect
- [Jane Iredale gives a $38 'value' gift with a $100 order](https://nudgeswipe.com/examples/jane-iredale-free-full-size-gift/): Jane Iredale, Email, Zero-price effect
- [Castlery frames referral as "a new beginning for them, a little thank-you for you"](https://nudgeswipe.com/examples/castlery-refer-both-get-100/): Castlery, Email, Incentive (principle)
- [The Guardian asks readers to give back for journalism they already read free](https://nudgeswipe.com/examples/guardian-reader-funded-support-ask/): The Guardian, Pricing, Reciprocity
- [Trainline replaces a list of Railcards with three questions](https://nudgeswipe.com/examples/trainline-railcard-finder-questions/): Trainline, Onboarding, Choice overload (simplification)
- [The FT dates its offer and starts at $1](https://nudgeswipe.com/examples/ft-limited-time-offers-dated/): Financial Times, Pricing, Urgency (deadline effect)
- [PureGym pairs a £0 joining fee with "ends Monday"](https://nudgeswipe.com/examples/puregym-zero-joining-fee-ends-monday/): PureGym, Homepage banner, Zero-price effect
- [Octopus leads with Which? and 891,063 reviews](https://nudgeswipe.com/examples/octopus-which-recommended-reviews/): Octopus Energy, Homepage, Authority
- [Netflix documents a three-step cancel and "That's it!"](https://nudgeswipe.com/examples/netflix-cancel-in-three-steps/): Netflix, Help / support (policy), Friction (principle)
- [Spotify's cancel article says you keep your playlists](https://nudgeswipe.com/examples/spotify-cancel-keep-your-playlists/): Spotify, Help / support (policy), Regret aversion (risk reversal)
- [Monzo sells budgeting as labelled Pots](https://nudgeswipe.com/examples/monzo-pots-salary-sorter/): Monzo, Homepage, Mental accounting
- [Starling ties budget Spaces to virtual cards](https://nudgeswipe.com/examples/starling-spaces-and-service-survey/): Starling Bank, Homepage, Mental accounting
- [Klaviyo leads with 'Start with a free plan' and lists the caps](https://nudgeswipe.com/examples/klaviyo-free-plan-limits-up-front/): Klaviyo, Pricing page, Zero-price effect
- [HubSpot shows Starter at $7 against $20, for a limited time](https://nudgeswipe.com/examples/hubspot-starter-strikethrough-limited-time/): HubSpot, Pricing page, Reference price
- [Zapier frames annual billing as 'Save 33%'](https://nudgeswipe.com/examples/zapier-pay-yearly-save-33/): Zapier, Pricing page, Price & attribute framing
- [Linear's pricing: 'Free for everyone' and 40,000 companies](https://nudgeswipe.com/examples/linear-free-for-everyone-40000-companies/): Linear, Pricing page, Social proof
- [Duolingo Super shows a three-step trial timeline](https://nudgeswipe.com/examples/duolingo-super-trial-reminder-timeline/): Duolingo, App onboarding / trial, Default effect / status quo bias
- [Booking.com Genius: levels you keep 'for life'](https://nudgeswipe.com/examples/booking-genius-levels-yours-for-life/): Booking.com, Loyalty page, Goal gradient (incl. endowed progress)
- [Gymshark rotates five offers in one top banner](https://nudgeswipe.com/examples/gymshark-rotating-incentive-banner/): Gymshark, Homepage banner, Incentive (principle)
- [Headspace preselects annual and shows it per month](https://nudgeswipe.com/examples/headspace-annual-preselected-monthly-equivalent/): Headspace, Pricing page, Default effect / status quo bias
- [Ocado uses Tesco's prices as its reference](https://nudgeswipe.com/examples/ocado-price-matched-to-tesco/): Ocado, Homepage, Reference price
- [Duolingo puts one giant "Get started" in front of everything](https://nudgeswipe.com/examples/duolingo-homepage-two-buttons-one-promise/): Duolingo, Homepage, Friction (principle)
- [Airbnb shows the total price and a "Guest favourite" badge on every card](https://nudgeswipe.com/examples/airbnb-total-price-and-guest-favourite/): Airbnb, Homepage, Social proof
- [Uber lets you "See prices" before you sign up](https://nudgeswipe.com/examples/uber-homepage-see-prices-before-sign-up/): Uber, Homepage, Friction (principle)
- [Booking.com answers "what if I change my mind?" before you search](https://nudgeswipe.com/examples/booking-com-free-cancellation-and-reviews-reassurance/): Booking.com, Homepage, Regret aversion (risk reversal)
- [Netflix leads with "Starts at US$8.99" and asks only for an email](https://nudgeswipe.com/examples/netflix-starts-at-cheapest-plan-email-first/): Netflix, Homepage / sign-up, Friction (principle)
- [Amazon frames the Prime trial as "30 days, on us"](https://nudgeswipe.com/examples/amazon-prime-30-days-on-us/): Amazon, Paywall / trial, Zero-price effect
- [Notion lets named founders and leaders make its case](https://nudgeswipe.com/examples/notion-homepage-customer-quotes-from-founders/): Notion, Homepage, Authority
- [YouTube Premium promises a reminder 7 days before the free month ends](https://nudgeswipe.com/examples/youtube-premium-trial-reminder-7-days/): YouTube, Paywall / trial, Zero-price effect
- [Strava turns its free trial into a three-step timeline](https://nudgeswipe.com/examples/strava-trial-timeline-today-2-days-30-days/): Strava, Paywall / trial, Regret aversion (risk reversal)
- [The New York Times strikes through $7.50 to sell All Access at $1 a week](https://nudgeswipe.com/examples/nyt-all-access-1-a-week-intro-price/): The New York Times, Paywall / pricing, Reference price
- [Canva puts a generous free plan first and a "Save from 16%" yearly toggle on top](https://nudgeswipe.com/examples/canva-pricing-free-plan-first-yearly-toggle/): Canva, Pricing page, Price & attribute framing
- [Dropbox badges its team plan "Best value" and defaults to yearly billing](https://nudgeswipe.com/examples/dropbox-best-value-badge-on-team-plan/): Dropbox, Pricing page, Default effect / status quo bias
- [GitHub opens its pricing page with a "risk-free" 30-day trial](https://nudgeswipe.com/examples/github-pricing-risk-free-30-day-trial/): GitHub, Pricing page, Regret aversion (risk reversal)
- [Grammarly says "$0 payment today" and promises a reminder 2 days before the trial ends](https://nudgeswipe.com/examples/grammarly-zero-payment-today-reminder/): Grammarly, Pricing page, Zero-price effect
- [NordVPN shows "Save 69%" on a 2-year plan, with the renewal price in small print](https://nudgeswipe.com/examples/nordvpn-save-69-intro-vs-renewal/): NordVPN, Pricing page, Reference price
- [Todoist puts "347K+ ★★★★★ reviews" above its plans](https://nudgeswipe.com/examples/todoist-reviews-count-and-free-forever-start/): Todoist, Pricing page, Social proof
- [Trello makes the free plan concrete: "Free for up to 10 collaborators"](https://nudgeswipe.com/examples/trello-free-for-10-collaborators/): Trello, Pricing page, Zero-price effect
- [Airtable marks its Team plan "Most popular" between Free and Business](https://nudgeswipe.com/examples/airtable-most-popular-team-plan/): Airtable, Pricing page, Social proof
- [Squarespace stacks an undated 20% code on top of a free trial](https://nudgeswipe.com/examples/squarespace-limited-time-20-off-code/): Squarespace, Pricing page, Incentive (principle)
- [ChatGPT puts an $8 step between Free and $20 Plus](https://nudgeswipe.com/examples/chatgpt-pricing-ladder-free-go-plus/): ChatGPT, Pricing page, Reference price
- [Monzo sells paid plans as "a bit more you", from £3 a month](https://nudgeswipe.com/examples/monzo-plans-from-3-a-month-bit-more-you/): Monzo, Pricing page, Price & attribute framing
- [Babbel runs a live countdown on a 20% "Lifetime" code](https://nudgeswipe.com/examples/babbel-countdown-timer-lifetime-code/): Babbel, Homepage banner, Urgency (deadline effect)
- [Deliveroo Plus sells a subscription as "free delivery"](https://nudgeswipe.com/examples/deliveroo-plus-savour-the-savings/): Deliveroo, Subscription page, Mental accounting
- [Asana labels its entry plan "Free forever" for one or two people](https://nudgeswipe.com/examples/asana-pricing-free-forever-for-two/): Asana, Pricing page, Zero-price effect
- [Calendly explains who needs a paid seat, and who doesn't](https://nudgeswipe.com/examples/calendly-always-free-plan-and-seat-explainer/): Calendly, Pricing page, Friction (principle)
- [Audible offers Prime members $0.99 a month for 4 months, plus a $20 credit](https://nudgeswipe.com/examples/audible-99-cents-for-4-months-prime-offer/): Audible, Homepage banner, Price & attribute framing
- [Perplexity stacks "LIMITED TIME" bonus credits on top of annual-billed prices](https://nudgeswipe.com/examples/perplexity-pro-limited-time-bonus-credits/): Perplexity, Pricing page, Incentive (principle)
- [Claude leads with the annual-discount price and spells out the monthly one beside it](https://nudgeswipe.com/examples/claude-pricing-annual-discount-shown-first/): Claude (Anthropic), Pricing page, Price & attribute framing
- [GitHub Copilot labels its $100 Max plan "BEST VALUE" by multiples of Pro credits](https://nudgeswipe.com/examples/github-copilot-four-tiers-best-value-max/): GitHub Copilot, Pricing page, Authority
- [Google sells Gemini plans as "2x" and "4x" the free usage](https://nudgeswipe.com/examples/google-ai-plans-usage-multiples/): Google Gemini, Pricing page, Price & attribute framing
- [Lovable frames the yearly plan as "2 months free" and starts with "No credit card needed"](https://nudgeswipe.com/examples/lovable-yearly-two-months-free-toggle/): Lovable, Pricing page, Price & attribute framing
- [Revolut prices each plan against a much bigger "worth £… a year" figure](https://nudgeswipe.com/examples/revolut-plans-worth-in-annual-benefits/): Revolut, Pricing page, Anchoring
- [Wise sells against hidden exchange-rate markups with "the mid-market rate"](https://nudgeswipe.com/examples/wise-pricing-other-providers-hide-fees/): Wise, Pricing page, Reference price
- [Chip leads with app-store ratings and the FSCS protection limit](https://nudgeswipe.com/examples/chip-app-ratings-and-fscs-protection/): Chip, Homepage, Social proof
- [Klarna leads with "120m users" and a Trustpilot score](https://nudgeswipe.com/examples/klarna-uk-120m-users-trust-stats/): Klarna, Homepage, Social proof
- [Club Pret: £5 a month for half price on up to five drinks a day](https://nudgeswipe.com/examples/club-pret-half-price-coffee-five-a-day/): Pret A Manger, Subscription page, Mental accounting
- [NOW strikes through £7.99 for £4.99, with a 6-month minimum term](https://nudgeswipe.com/examples/now-entertainment-saver-6-month-minimum/): NOW, Homepage, Reference price
- [The Times sells a puzzles-only side door: "£1 for your first 3 months"](https://nudgeswipe.com/examples/times-puzzles-1-pound-for-3-months/): The Times, Subscribe page, Zero-price effect
- [BT states each future price rise in pounds next to the deal](https://nudgeswipe.com/examples/bt-full-fibre-price-rises-in-pounds/): BT, Broadband deals page, Price & attribute framing
- [Currys promises "Found it cheaper? We'll match it" and shows the 29.9% APR](https://nudgeswipe.com/examples/currys-price-match-and-flexpay-apr/): Currys, Homepage, Regret aversion (risk reversal)
- [Argos puts its delivery fees in the header, next to "A year of fast delivery with Argos Plus"](https://nudgeswipe.com/examples/argos-delivery-fees-and-argos-plus/): Argos, Homepage, Partitioned pricing
- [Peloton App: "Try 30 days free", then from £12.99 a month](https://nudgeswipe.com/examples/peloton-app-uk-30-days-free/): Peloton, App page, Zero-price effect
- [LinkedIn Premium splits visitors into "Advance your career" or "Grow your business" before any price](https://nudgeswipe.com/examples/linkedin-premium-two-free-trial-paths/): LinkedIn Premium, Premium landing page, Choice overload (simplification)
- [Noom asks "See if you qualify" rather than "Buy"](https://nudgeswipe.com/examples/noom-see-if-you-qualify/): Noom, Homepage, Commitment & consistency
- [ZOE leads with first-name member quotes and "world-leading science"](https://nudgeswipe.com/examples/zoe-member-stories-daily30/): ZOE, Homepage, Social proof
- [Uber One sells a £4.99 membership on "£0 Delivery Fee" and credits paid back as a percentage](https://nudgeswipe.com/examples/uber-one-zero-delivery-fee-membership/): Uber One, Membership page, Zero-price effect
- [Jet2holidays leads with a "£60pp deposit" and lists what is included](https://nudgeswipe.com/examples/jet2holidays-60pp-deposit-number-one-operator/): Jet2holidays, Homepage, Pain of paying
- [lastminute.com runs a ticking "Ends in" countdown over its "Only here" deals](https://nudgeswipe.com/examples/lastminute-deals-countdown-only-here/): lastminute.com, Homepage, Urgency (deadline effect)
- [MoneySuperMarket attaches "Earn £15" to a quote and promises to price-match and more](https://nudgeswipe.com/examples/moneysupermarket-supersaveclub-rewards/): MoneySuperMarket, Homepage, Incentive (principle)
- [Compare the Market leads with "Save up to £566" and footnotes that 51% could achieve it](https://nudgeswipe.com/examples/compare-the-market-save-up-to-51-percent/): Compare the Market, Homepage, Anchoring
- [Uswitch gives its reasons ("That's why more people come to us") under a TrustScore](https://nudgeswipe.com/examples/uswitch-reasons-and-trustscore/): Uswitch, Homepage, Reason-giving ("because")
- [EE prints each future price rise in pounds and pence under the headline monthly price](https://nudgeswipe.com/examples/ee-price-rises-in-pounds-and-pence/): EE, Homepage, Partitioned pricing
- [Three leads with "Save up to £1035" on trade-in and dates its price rises](https://nudgeswipe.com/examples/three-save-up-to-with-trade-in/): Three, Homepage, Anchoring
- [Sky frames Ultimate TV as "less than £1 a day" and bundles brand-name streamers](https://nudgeswipe.com/examples/sky-ultimate-tv-less-than-1-a-day/): Sky, Homepage, Price & attribute framing
- [Moonpig pairs a "FREE CARD with any bouquet" with 30% off the first card](https://nudgeswipe.com/examples/moonpig-free-card-with-bouquet/): Moonpig, Homepage, Zero-price effect
- [ElevenLabs strikes through $6 to show "First month 83% off" until 18 October](https://nudgeswipe.com/examples/elevenlabs-first-month-83-off-until/): ElevenLabs, Pricing page, Reference price
- [Runway translates credits into seconds of video and frames annual billing as "Save $84/year"](https://nudgeswipe.com/examples/runway-credits-translated-to-seconds/): Runway, Pricing page, Mental accounting
- [Suno's free plan is a list of "No…" lines; Pro is "MOST POPULAR", Premier "BEST VALUE"](https://nudgeswipe.com/examples/suno-free-plan-lists-what-you-dont-get/): Suno, Pricing page, Loss aversion
- [Replit shows "$20 $18 / month, billed annually" and bundles model credit into the price](https://nudgeswipe.com/examples/replit-billed-annually-price-shown-struck/): Replit, Pricing page, Price & attribute framing
- [Bolt promises "Unused tokens roll over" and a "Save up to 28%" annual toggle](https://nudgeswipe.com/examples/bolt-unused-tokens-roll-over/): Bolt, Pricing page, Loss aversion
- [v0 gives "$2 of free daily credits on login" and a one-time $5 for new users](https://nudgeswipe.com/examples/v0-daily-credits-on-login/): v0 (Vercel), Pricing page, Incentive (principle)
- [Oddbox leads with "68,000+ TONNES RESCUED" and promises you can "switch, swap or stop at any time"](https://nudgeswipe.com/examples/oddbox-tonnes-rescued-switch-swap-stop/): Oddbox, Homepage, Affect heuristic
- [Zopa lines up "14 times winner at the British Bank Awards" above its app features](https://nudgeswipe.com/examples/zopa-award-strip/): Zopa, Homepage, Authority
- [Trading 212 shows a sample "Your earnings" widget from share lending, under a risk warning](https://nudgeswipe.com/examples/trading-212-sample-earnings-widget/): Trading 212, Homepage, Availability heuristic
- [Descript tags its middle "Creator" plan "MOST POPULAR" with a struck monthly price](https://nudgeswipe.com/examples/descript-annual-saving-most-popular/): Descript, Pricing page, Compromise effect
- [Freetrade repeats "FREE" three times and leans on FCA and IG Group](https://nudgeswipe.com/examples/freetrade-free-isa-free-pension/): Freetrade, Homepage, Zero-price effect
- [Global Work & Travel frames its Early Bird as a way to "skip" a price increase](https://nudgeswipe.com/examples/global-work-travel-skip-the-price-increase/): Global Work & Travel, Email, Loss aversion
- [Ski.com counts down "4 days left" to an Epic Pass price rise](https://nudgeswipe.com/examples/ski-com-days-left-before-epic-pass-increase/): Ski.com, Email, Urgency (deadline effect)
- [The Tight Spot asks "Why pay more later?" with old and new Wolford prices side by side](https://nudgeswipe.com/examples/the-tight-spot-wolford-why-pay-more-later/): The Tight Spot, Email, Loss aversion
- [Baloo Living says its linen "should cost more", then adds "soon it will"](https://nudgeswipe.com/examples/baloo-living-linen-should-cost-more/): Baloo Living, Email, Price-quality heuristic

## Biases
- [Anchoring](https://nudgeswipe.com/biases/anchoring/): An initial number, even an irrelevant one, pulls later estimates towards it. (strong evidence)
- [Reference price](https://nudgeswipe.com/biases/reference-price/): A price is judged against a comparison price: a 'was' price, a monthly rate, a renewal rate. (strong evidence)
- [Social proof](https://nudgeswipe.com/biases/social-proof/): When unsure, we look at what people like us do. (strong evidence)
- [Authority](https://nudgeswipe.com/biases/authority/): We defer to signals of expertise or official endorsement. (strong evidence)
- [Reciprocity](https://nudgeswipe.com/biases/reciprocity/): A favour received creates a felt obligation to return it. (strong evidence)
- [Loss aversion](https://nudgeswipe.com/biases/loss-aversion/): Losses tend to loom larger than equivalent gains. (mixed evidence)
- [Regret aversion (risk reversal)](https://nudgeswipe.com/biases/regret-aversion/): People avoid choices they expect to regret; removing the downside removes the regret. (strong evidence)
- [Endowment effect](https://nudgeswipe.com/biases/endowment-effect/): We value things more once they feel like ours. (strong evidence)
- [Default effect / status quo bias](https://nudgeswipe.com/biases/default-status-quo/): People tend to stick with whatever is preselected or already happening. (strong evidence)
- [Choice overload (simplification)](https://nudgeswipe.com/biases/choice-overload/): Too many options can stall a decision; simplifying can help. (mixed evidence)
- [Decoy effect](https://nudgeswipe.com/biases/decoy-effect/): An inferior third option can make one of the other two look better. (mixed evidence)
- [Zero-price effect](https://nudgeswipe.com/biases/zero-price-effect/): 'Free' is treated as more than just a lower price. (mixed evidence)
- [Price & attribute framing](https://nudgeswipe.com/biases/price-framing/): The same price or attribute feels different depending on how it's expressed. (strong evidence)
- [Mental accounting](https://nudgeswipe.com/biases/mental-accounting/): People put money into mental buckets and treat it differently by bucket. (mixed evidence)
- [Present bias](https://nudgeswipe.com/biases/present-bias/): Costs and rewards now weigh more than the same ones later. (strong evidence)
- [Urgency (deadline effect)](https://nudgeswipe.com/biases/urgency/): A limited time to act prompts action now. (strong evidence)
- [Scarcity](https://nudgeswipe.com/biases/scarcity/): Things in limited quantity seem more valuable. (mixed evidence)
- [Goal gradient (incl. endowed progress)](https://nudgeswipe.com/biases/goal-gradient/): Effort rises as people approach a goal, and a head start makes them more likely to finish. (strong evidence)
- [Commitment & consistency](https://nudgeswipe.com/biases/commitment-consistency/): After a small commitment, people act to stay consistent with it. (strong evidence)
- [Peak-end rule](https://nudgeswipe.com/biases/peak-end/): Experiences are remembered by their peak and their ending. (strong evidence)
- [IKEA effect](https://nudgeswipe.com/biases/ikea-effect/): We value things more when we've helped make them. (strong evidence)
- [Information gap (curiosity)](https://nudgeswipe.com/biases/information-gap/): A gap between what we know and want to know creates curiosity. (mixed evidence)
- [Friction (principle)](https://nudgeswipe.com/biases/friction/): Not a bias: small hassles strongly change behaviour. Make the desired action easy. (strong evidence)
- [Incentive (principle)](https://nudgeswipe.com/biases/incentive/): Not a bias: a reward for doing something, such as a referral reward or sign-up discount. (strong evidence)
- [Availability heuristic](https://nudgeswipe.com/biases/availability-heuristic/): We judge how likely or common something is by how easily examples come to mind. (strong evidence)
- [Confirmation bias](https://nudgeswipe.com/biases/confirmation-bias/): We look for, notice and remember evidence that fits what we already believe. (strong evidence)
- [Overconfidence](https://nudgeswipe.com/biases/overconfidence/): We are more sure of our judgements than our accuracy justifies. (strong evidence)
- [Planning fallacy](https://nudgeswipe.com/biases/planning-fallacy/): We underestimate how long our own tasks will take, even when similar tasks ran late before. (strong evidence)
- [Optimism bias](https://nudgeswipe.com/biases/optimism-bias/): We think good things are more likely, and bad things less likely, to happen to us than to others. (strong evidence)
- [Illusion of control](https://nudgeswipe.com/biases/illusion-of-control/): We overestimate how much we can influence outcomes that are largely down to chance. (strong evidence)
- [Sunk cost effect](https://nudgeswipe.com/biases/sunk-cost/): We keep investing in something because of what we've already put in, not what we'll get. (mixed evidence)
- [Certainty effect](https://nudgeswipe.com/biases/certainty-effect/): We overweight outcomes that are certain compared with ones that are merely likely. (strong evidence)
- [Ambiguity aversion](https://nudgeswipe.com/biases/ambiguity-aversion/): We prefer known risks to unknown ones, even when the unknown might be better. (strong evidence)
- [Mere-exposure effect](https://nudgeswipe.com/biases/mere-exposure/): We tend to like things more the more often we've seen them. (strong evidence)
- [Serial position effect](https://nudgeswipe.com/biases/serial-position/): We remember the first and last items in a list best. (strong evidence)
- [Isolation (Von Restorff) effect](https://nudgeswipe.com/biases/von-restorff/): An item that stands out from the rest is more likely to be noticed and remembered. (strong evidence)
- [Spacing effect](https://nudgeswipe.com/biases/spacing-effect/): We remember better when practice is spread out over time rather than crammed. (strong evidence)
- [Hick's law](https://nudgeswipe.com/biases/hicks-law/): The time it takes to choose grows with the number and complexity of options. (strong evidence)
- [Fitts's law](https://nudgeswipe.com/biases/fitts-law/): The time to hit a target depends on its size and distance. (strong evidence)
- [Working-memory limits](https://nudgeswipe.com/biases/working-memory-limits/): We can hold only a few chunks of information in mind at once: about three to five, rather than Miller's often-quoted "seven". (strong evidence)
- [Cognitive load](https://nudgeswipe.com/biases/cognitive-load/): Mental effort spent on processing a task leaves less capacity for learning or judging it. (strong evidence)
- [Change blindness](https://nudgeswipe.com/biases/change-blindness/): We often fail to notice large changes to a scene, especially across a break or page load. (strong evidence)
- [Inattentional blindness](https://nudgeswipe.com/biases/inattentional-blindness/): When focused on one thing, we can miss something unexpected in plain sight. (strong evidence)
- [Aesthetic-usability effect](https://nudgeswipe.com/biases/aesthetic-usability/): We perceive attractive designs as easier to use. (limited evidence)
- [Processing fluency](https://nudgeswipe.com/biases/processing-fluency/): Information that's easy to process feels more true, likeable and familiar. (strong evidence)
- [Labour illusion](https://nudgeswipe.com/biases/labor-illusion/): We value a service more when we can see the effort that goes into it. (limited evidence)
- [Pratfall effect](https://nudgeswipe.com/biases/pratfall-effect/): A small blunder can make a highly competent person more likeable. (limited evidence)
- [Halo effect](https://nudgeswipe.com/biases/halo-effect/): One positive trait colours our judgement of unrelated traits. (strong evidence)
- [Conformity](https://nudgeswipe.com/biases/conformity/): Under direct group pressure we may go along with a majority, even against what we can see is true (Asch-style conformity). (strong evidence)
- [In-group bias](https://nudgeswipe.com/biases/in-group-bias/): We favour people who belong to our own group, even when the groups are trivially defined. (strong evidence)
- [Similarity–liking](https://nudgeswipe.com/biases/similarity-liking/): We like people who are similar to us, including in their attitudes. (strong evidence)
- [Door-in-the-face](https://nudgeswipe.com/biases/door-in-the-face/): After refusing a big request, we're more likely to agree to a smaller one. (strong evidence)
- [That's-not-all technique](https://nudgeswipe.com/biases/thats-not-all/): Adding a bonus or discount before the person responds makes them more likely to accept. (strong evidence)
- [Low-ball technique](https://nudgeswipe.com/biases/low-ball/): Once committed to a deal, we often accept it even when the cost goes up. (strong evidence)
- [Reason-giving ("because")](https://nudgeswipe.com/biases/reason-giving/): Requests that come with a reason are more often granted, even when the reason is thin. (limited evidence)
- [Reactance](https://nudgeswipe.com/biases/reactance/): When we feel our freedom is threatened, we push back and want the restricted thing more. (strong evidence)
- [Curse of knowledge](https://nudgeswipe.com/biases/curse-of-knowledge/): Once we know something, it's hard to imagine not knowing it. (limited evidence)
- [Dunning–Kruger effect](https://nudgeswipe.com/biases/dunning-kruger/): People with low skill in an area tend to overestimate their ability. (mixed evidence)
- [Choice-supportive bias](https://nudgeswipe.com/biases/choice-supportive-bias/): After choosing, we remember the chosen option as better than it was. (limited evidence)
- [Cognitive dissonance](https://nudgeswipe.com/biases/cognitive-dissonance/): Holding conflicting beliefs or actions is uncomfortable, so we adjust our attitudes to fit what we did. (mixed evidence)
- [Effort justification](https://nudgeswipe.com/biases/effort-justification/): We value things more when we've worked or suffered to get them. (limited evidence)
- [Pain of paying](https://nudgeswipe.com/biases/pain-of-paying/): Paying feels unpleasant, and that pain depends on how and when we pay. (strong evidence)
- [Credit-card premium](https://nudgeswipe.com/biases/credit-card-premium/): People may be willing to pay more when using a card than cash. (limited evidence)
- [Left-digit effect](https://nudgeswipe.com/biases/left-digit-effect/): We judge prices largely by their first digit, so £2.99 feels much cheaper than £3.00. (strong evidence)
- [Price-quality heuristic](https://nudgeswipe.com/biases/price-quality-heuristic/): We use price as a cue to quality, and a higher price can even make something taste better to us. (limited evidence)
- [Compromise effect](https://nudgeswipe.com/biases/compromise-effect/): We favour the middle option when choices range from low to high. (mixed evidence)
- [Partitioned pricing](https://nudgeswipe.com/biases/partitioned-pricing/): Splitting a price into a base price plus surcharges can make the total seem lower. (strong evidence)
- [Denomination effect](https://nudgeswipe.com/biases/denomination-effect/): We are less likely to spend money held in a large denomination than the same amount in smaller units. (limited evidence)
- [Fresh start effect](https://nudgeswipe.com/biases/fresh-start-effect/): Temporal landmarks like New Year, a birthday or a Monday make us more likely to pursue goals. (limited evidence)
- [Implementation intentions](https://nudgeswipe.com/biases/implementation-intentions/): Planning exactly when, where and how we'll act makes us more likely to follow through. (strong evidence)
- [Temptation bundling](https://nudgeswipe.com/biases/temptation-bundling/): Pairing something we should do with something we want to do helps us do the first. (limited evidence)
- [Overjustification effect](https://nudgeswipe.com/biases/overjustification/): External rewards can reduce our intrinsic motivation for an activity we already enjoyed. (mixed evidence)
- [Licensing effect](https://nudgeswipe.com/biases/licensing-effect/): After doing something good, we feel licensed to indulge or behave less well. (mixed evidence)
- [Identity labelling](https://nudgeswipe.com/biases/identity-labelling/): Describing a behaviour as part of who we are ("be a voter") can motivate it. (mixed evidence)
- [Choice blindness](https://nudgeswipe.com/biases/choice-blindness/): We can fail to notice when what we get is not what we chose, and still justify it. (limited evidence)
- [Affect heuristic](https://nudgeswipe.com/biases/affect-heuristic/): Our feelings about something shape our judgement of its risks and benefits. (strong evidence)
- [Identifiable victim effect](https://nudgeswipe.com/biases/identifiable-victim/): We tend to help one named person more than many statistical victims. (mixed evidence)
- [Hot–cold empathy gap](https://nudgeswipe.com/biases/hot-cold-empathy-gap/): In a calm state we underestimate how much hunger, anger or desire will change our choices, and vice versa. (strong evidence)
- [Projection bias](https://nudgeswipe.com/biases/projection-bias/): We assume our future preferences will match our current ones. (limited evidence)
- [Diversification bias](https://nudgeswipe.com/biases/diversification-bias/): When choosing several items at once, we pick more variety than we'll actually want. (strong evidence)
- [Focusing illusion](https://nudgeswipe.com/biases/focusing-illusion/): Whatever we focus on seems more important than it is. (limited evidence)
- [Negativity bias](https://nudgeswipe.com/biases/negativity-bias/): Bad events and information affect us more than equally good ones. (strong evidence)
- [Distinction bias](https://nudgeswipe.com/biases/distinction-bias/): Comparing options side by side makes small differences seem bigger than they will feel in use. (limited evidence)
- [Less-is-better effect](https://nudgeswipe.com/biases/less-is-better/): A lower-value option can be valued more when judged alone than a higher-value one. (limited evidence)
- [Unit bias](https://nudgeswipe.com/biases/unit-bias/): We treat one unit as the right amount, whatever its size. (limited evidence)
- [Ostrich effect](https://nudgeswipe.com/biases/ostrich-effect/): We avoid information we expect to be unpleasant. (limited evidence)
- [Barnum effect](https://nudgeswipe.com/biases/barnum-effect/): We accept vague, general descriptions as accurate about ourselves. (strong evidence)
- [Illusory truth effect](https://nudgeswipe.com/biases/illusory-truth/): Repeated statements feel more true, whether or not they are. (strong evidence)
- [Marketing placebo effect](https://nudgeswipe.com/biases/marketing-placebo/): Marketing such as price can change how well a product actually works for us. (limited evidence)
- [Scope insensitivity](https://nudgeswipe.com/biases/scope-insensitivity/): Our willingness to pay or help barely changes with the size of the problem. (limited evidence)
- [Rhyme-as-reason effect](https://nudgeswipe.com/biases/rhyme-as-reason/): Rhyming statements can seem more accurate than non-rhyming ones. (limited evidence)
- [Self-reference effect](https://nudgeswipe.com/biases/self-reference-effect/): We remember information better when it relates to ourselves. (strong evidence)
- [Name-letter effect](https://nudgeswipe.com/biases/name-letter-effect/): We tend to prefer the letters in our own name. (limited evidence)
- [Social comparison](https://nudgeswipe.com/biases/social-comparison/): We evaluate ourselves by comparing with others. (strong evidence)
- [Mere-measurement effect](https://nudgeswipe.com/biases/mere-measurement/): Being asked about our intentions can change our behaviour. (limited evidence)