Cognitive biases are systematic patterns of deviation from rationality in judgment and decision-making. First popularized by Kahneman and Tversky in the 1970s, these mental shortcuts (heuristics) help our brains process information efficiently but often lead to predictable errors. Understanding these biases is critical for anyone making consequential decisions—from business leaders and investors to healthcare professionals and everyday problem-solvers. The key insight: we are all susceptible to these biases, often without awareness, and recognizing them is the first step toward better judgment. This cheat sheet catalogs over 40 major biases, organized from foundational information-processing distortions through social dynamics, with practical debiasing strategies to help you make clearer, more rational choices.
What This Cheat Sheet Covers
This topic spans 14 focused tables and 75 indexed concepts. Below is a complete table-by-table outline of this topic, spanning foundational concepts through advanced details.
Table 1: Foundational Information Processing Biases
These are the bedrock distortions that warp how raw information gets weighted before any deeper reasoning kicks in — the mental shortcuts Kahneman and Tversky first studied. Anchoring on an opening number, judging risk by whatever springs to mind, mistaking a stereotype for a probability: each one quietly corrupts the inputs to a decision, so they tend to feed every bias that follows.
| Bias | Example | Description |
|---|---|---|
Initial asking price 500k influences all subsequent negotiations even when market value is 300k | • Overreliance on the first piece of information encountered when making decisions • subsequent judgments are "anchored" to this initial value regardless of relevance | |
Overestimating plane crash risk after seeing news coverage, while underestimating car accident risk | • Judging probability based on how easily examples come to mind rather than actual statistical frequency • vivid or recent events are overweighted | |
Assuming someone wearing glasses and reading is a librarian rather than a farmer (ignoring base rates) | Judging likelihood by how well something matches a stereotype or prototype, while ignoring actual statistical probabilities (base rates). |