psychology

Cognitive Biases & Decision Science

The systematic errors in human thinking — why we misjudge probabilities, overweight losses, and anchor to irrelevant numbers.

cognitive biasKahnemanprospect theoryBayesdecision-makingheuristics

Cognitive biases are systematic patterns of deviation from rationality in judgment. Discovered and catalogued by Daniel Kahneman and Amos Tversky starting in the 1970s, these biases reveal that human decision-making is predictably irrational — shaped by mental shortcuts (heuristics) that usually work but sometimes fail spectacularly.

Prospect theory, which earned Kahneman the Nobel Prize in 2002, showed that people feel losses roughly twice as strongly as equivalent gains, overweight small probabilities, and evaluate outcomes relative to reference points rather than absolute values. These insights revolutionized economics, finance, public policy, and medicine.

These simulations let you experience cognitive biases firsthand: update beliefs with Bayes' theorem, see how prospect theory warps your valuation of risks, watch anchoring shift your estimates, and discover how survivorship bias creates false narratives of success.

4 interactive simulations

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Anchoring Effect Simulator

Simulate how an initial anchor biases a population of estimates through insufficient adjustment, visualized as histogram and scatter plot

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Bayes' Theorem Visualizer

Explore how prior beliefs update with evidence using Bayes' theorem, with probability trees and natural frequency displays

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Prospect Theory Value Function

Visualize Kahneman-Tversky's S-shaped value function and probability weighting — the foundation of behavioral economics

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Survivorship Bias Simulator

Simulate selection bias in company returns — see how looking only at survivors inflates perceived performance