The Representativeness Heuristic

Misconception vs. Truth

Misconception:
Knowing a person’s history makes it easier to determine what sort of person they are.

Truth:
You jump to conclusions based on how representative a person seems to be of a preconceived character type.

The Representativeness Heuristic

  • Definition: A cognitive shortcut where people judge the probability of an event or individual based on how closely they match a prototype or stereotype.
  • Example: Assuming a podiatrist is unlikely to be spontaneous or unpredictable, based on stereotypes rather than actual knowledge.

Research by Kahneman and Tversky

  • Study Setup: Participants read descriptions of individuals and then guessed their occupations from a selection of engineers and lawyers.
    • Example Description: Donald, an orderly and emotionless student likely to be an engineer.
    • Statistical Ignorance: Participants ignored base rates (70% lawyers and 30% engineers) and chose based on representativeness.

The Conjunction Fallacy

  • Explanation: People misjudge the probability of combined events as being more probable than single events.
    • Example: Linda, a socially active philosophy major, is judged more likely to be a bank teller and a feminist, despite it being statistically less likely.

Real-life Application and Perception

  • Futurists’ Predictions: Professional forecasters also fall prey to representativeness heuristics by considering complex scenarios (e.g., suspending relations and invasions) more likely than simple ones.

Implications of Representativeness Heuristic

  • Utility and Danger: While it helps in quick decision-making and avoiding immediate dangers, it also fuels generalizations, stereotypes, and prejudices.

Key Points

  • Emotional vs. Rational Thinking: People rely on narratives and characters that align with preconceived notions rather than statistical reasoning.
  • Prejudices: Expecting people to fit stereotypes can lead to misjudgments and reinforces not-so-smart thinking patterns.