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A Taxonomy of Cognitive Biases

Over the past fifty years, researchers have catalogued hundreds of distinct cognitive biases. The sheer number can be overwhelming — a 2016 visual codex by writer Buster Benson and designer John Manoogian III organised approximately 188 named biases into a single diagram. Rather than memorising a…

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A Taxonomy of Cognitive Biases

Mapping the Territory

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Photo by Clément Falize on Unsplash

Over the past fifty years, researchers have catalogued hundreds of distinct cognitive biases. The sheer number can be overwhelming — a 2016 visual codex by writer Buster Benson and designer John Manoogian III organised approximately 188 named biases into a single diagram. Rather than memorising a list, it is more useful to understand the underlying architecture: why so many biases exist, and what cognitive problems they arise from.

Benson's framework proposes that all cognitive biases are responses to four fundamental problems the brain must solve under constraints of time, information, and memory.

Problem 1: Too Much Information

A close up of an open book with writing on it

Photo by Brett Jordan on Unsplash

The world generates far more data than the brain can process. To cope, we filter aggressively — but the filters themselves introduce distortion. We notice things that confirm what we already believe (confirmation bias). We are disproportionately drawn to unusual, vivid, or emotionally charged information (availability heuristic). We pay more attention to changes and differences than to absolute values (change bias).

These filters are efficient but selective. What passes through shapes our model of reality; what is filtered out is simply missing.

Problem 2: Not Enough Meaning

a page of a book with writing

Photo by Brett Jordan on Unsplash

Information rarely arrives with a complete context. We fill the gaps with stories, patterns, and assumptions. We find patterns even in noise (apophenia — finding connections that don't exist). We project our own knowledge and perspective onto others, assuming they see what we see (curse of knowledge). We construct coherent narratives from incomplete evidence and then treat those narratives as facts (narrative fallacy).

The brain's meaning-making machinery is extraordinarily creative — and correspondingly prone to generating plausible-seeming fictions.

Problem 3: Need to Act Fast

Chapter 6 Regression Models for Overdispersed CountResponse book page

Photo by Enayet Raheem on Unsplash

Decisions often need to be made quickly, without complete information. We are biased toward action and completion, even when waiting would be wiser (action bias). We maintain prior beliefs and decisions longer than the evidence warrants (status quo bias, sunk cost fallacy). We prefer safe, certain outcomes over uncertain ones with higher expected value (risk aversion).

These tendencies keep us moving and protect us from the paralysis of infinite deliberation — at the cost of systematic errors in how we evaluate options.

Problem 4: What to Remember

Chapter 6 Regression Models for Overdispersed CountResponse book page

Photo by Enayet Raheem on Unsplash

Memory is not a recording device. It is reconstructive — we rebuild memories from fragments each time we recall them, and the reconstruction process introduces errors. We simplify and generalise experiences (stereotyping). We edit memories in light of later information (hindsight bias). We remember the peak and end of an experience more than the whole (peak-end rule, studied by Kahneman and colleagues).

Memory biases matter in finance because we constantly learn from experience — and if our memories of past decisions are distorted, our learning is compromised.

Biases Cluster into Families

Assortment of colorful 3D abstract objects floating against black background

Photo by Nigel Hoare on Unsplash

Within these four categories, biases group into recognisable families:

  • Information processing biases: confirmation bias, availability heuristic, representativeness heuristic
  • Memory and narrative biases: hindsight bias, narrative fallacy, rosy retrospection
  • Social and self-perception biases: Dunning-Kruger effect, fundamental attribution error, in-group bias
  • Decision and risk biases: loss aversion, anchoring, framing effects, present bias

The families overlap and interact. Understanding the architecture — rather than memorising individual biases — gives you a lens that applies across new situations you haven't explicitly studied.

Educational content only. Not financial, investment, tax or legal advice. Learn more

Quiz me on this
According to Buster Benson's framework, what is the underlying cause of all cognitive biases?
  1. Laziness and a preference for quick decisions over careful analysis
  2. ✓ The brain's responses to four fundamental constraints: too much information, too little meaning, the need to act fast, and limits of memory
  3. Emotional interference with logical reasoning
  4. Cultural and social conditioning that overrides rational thought
Why does having too much information lead to cognitive bias?
  1. Excess information causes cognitive overload and complete decision paralysis
  2. ✓ The brain's filtering mechanisms introduce distortion — what passes through shapes our model of reality, while filtered-out information is simply absent
  3. People with more information always make worse decisions than those with less
  4. The brain treats all information as equally relevant, making prioritisation impossible
Why is memory particularly important as a source of cognitive bias?
  1. Memory is perfectly accurate but we choose to remember things selectively
  2. Poor memory leads directly to poor arithmetic and financial calculation
  3. ✓ Memory is reconstructive, not a recording — we rebuild it each time, introducing errors that shape what we learn from experience
  4. Short-term memory is reliable but long-term memory is completely unreliable
What is the practical advantage of understanding the four-category taxonomy rather than memorising individual bias names?
  1. The taxonomy is required knowledge for financial qualifications
  2. Individual bias names are too technical for non-specialists to use
  3. ✓ Understanding the underlying structure gives you a lens that applies to new situations not covered by any specific named bias
  4. The taxonomy reduces the number of biases you need to worry about to just four