Anchoring bias
The first number you see disproportionately shapes every judgment that follows.
Bias Handbook
CBD Ecosystem · iOS App
Every bias behind every decision
A beautifully illustrated field guide to 194 cognitive and behavioral biases, each with a one-glance diagram, the classic studies, and the frameworks behind it. Built by the Center for Behavioral Decisions.
194Biases
5Categories
12Frameworks
100%Offline & private
Inside the app
A reference you’ll actually want to open
Not a wall of definitions, a designed, cross-linked, citation-backed handbook that makes each bias click.
One-glance diagrams
Most entries open with a hand-drawn schematic, an anchor dragging an estimate, a filter blocking evidence, a tipped scale. The idea lands before you read a word.
Smart, tappable citations
Cross-links jump you between related biases in a tap; references open the Wikipedia article or the original paper in Safari.
Grounded in the literature
Every bias carries a short “In the literature” note, the theoretical lineage, the key reviews, the live debates, distilled from primary sources.
Classic studies, not just definitions
Real experiments on every page: Tversky & Kahneman’s rigged wheel of fortune, Loftus on false memories, Pronin on the bias blind spot.
Search, filter & shuffle
Find any of the 194 biases instantly, narrow by category, or tap shuffle when you want to be surprised by one.
Bookmarks & private notes
Save the biases you return to and write your own examples, kept entirely on your device, synced nowhere.
Five families
Every bias, sorted by how it bends your thinking
46
Decision-making
Anchoring · framing · sunk cost · loss aversion
50
Belief & probability
Confirmation bias · availability · gambler’s fallacy
37
Social
Halo effect · in-group bias · attribution error
36
Memory
Hindsight bias · misinformation effect · peak–end
25
194
Self-perception
Dunning–Kruger · overconfidence · self-serving bias
See them all →
The full catalog, on the App Store.
A taste of what’s inside
Six you’ll recognize the moment you read them
Confirmation bias
We search for, read, and remember information in ways that confirm what we already believe.
Sunk-cost fallacy
We keep investing because of what we’ve already spent, not what we’ll actually get back.
Dunning–Kruger effect
The less skill we have in a domain, the more we tend to overestimate it.
Loss aversion
Losses hurt about twice as much as equivalent gains feel good.
Availability heuristic
If examples come to mind easily, we assume they’re far more common than they are.
Not just a glossary
12 behavioral frameworks, mapped out
The models practitioners actually use to change behavior, each one diagrammed and explained, so a bias becomes something you can act on.
COM-BCapability · Opportunity · Motivation
BCWBehaviour Change Wheel
TDFTheoretical Domains Framework
BCTTv1Behaviour Change Technique Taxonomy
EASTEasy · Attractive · Social · Timely
MINDSPACENine levers of behavior
NudgeNudge & Choice Architecture
B=MAPFogg Behaviour Model
SDTSelf-Determination Theory
S1 · S2Dual-Process Theory
TPBTheory of Planned Behaviour
TTMTranstheoretical (Stages of Change)
Private by design
“Data Not Collected.”
Bias Handbook is a fully offline reference. The entire catalog ships inside the app and is read from your device, so there’s nothing to leak.
- No account, no sign-in, no email required
- No analytics, crash trackers, or advertising SDKs
- Nothing is sent to any server, ever
- Bookmarks & notes stay in your device’s sandbox
- Works on a plane, in a tunnel, anywhere
Who it’s for
Anyone whose work runs on judgment
- Founders & product teams
- Designers & researchers
- Students & educators
- Analysts & investors
- Coaches & clinicians
- Anyone who makes decisions
Designed and produced by the Center for Behavioral Decisions; published on the App Store by StepApp, Inc. Sourced from Wikipedia’s List of cognitive biases and the underlying primary literature, Tversky & Kahneman, Slovic, Loftus, Gilovich, Pronin, Loewenstein, Roediger, Carstensen, Pettigrew, and others.
Get the app
Sharpen every decision you make
194 biases, 12 frameworks, and the science behind them, offline and always in your pocket.
iOS 17+ · No ads, no tracking