Definition
The Representative Heuristic is a mental shortcut used when making judgments about the probability of an event under uncertainty. It involves estimating the likelihood of an event based on how much it resembles (is representative of) a particular prototype or stereotype, while often ignoring relevant statistical facts like base rates.
Why It Matters
We often choose the ‘stereotypical’ option over the ‘probable’ one. This associative error leads to systemic bias, poor investment choices, and a failure to see the world as it actually is, often at the cost of justice and efficiency.
Core Concepts
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Similarity vs. Probability: The error of assuming that because looks like , must come from .
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How to read: “The assumption because A looks like B, A must come from B.”
- Meaning: Resemblance is not probability—base rates determine how likely actually belongs to category .
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Base Rate Neglect: Ignoring the general prevalence of a category in favor of specific, vivid details (e.g., the “Linda Problem”).
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Insensitivity to Sample Size: Assuming that a small sample is as representative of a population as a large sample.
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Conjunction Fallacy: The belief that specific conditions (Bank Teller + Feminist) are more probable than a single general one (Bank Teller).