Heuristics and Biases in Judgment under Uncertainty
Representativeness, availability, and anchoring simplify judgments under uncertainty. They often work well, but can produce predictable errors when resemblance, ease of recall, or an initial value substitutes for relevant evidence.
THE IDEA
Three heuristics commonly guide judgments under uncertainty: (i) representativeness, which is usually employed when people are asked to judge the probability that an object or event A belongs to class or process B; (ii) availability of instances or scenarios, which is often employed when people are asked to assess the frequency of a class or the plausibility of a particular development; and (iii) adjustment from an anchor, which is usually employed in numerical prediction when a relevant value is available. These heuristics are highly economical and usually effective, but they lead to systematic and predictable errors. A better understanding of these heuristics and of the biases to which they lead could improve judgments and decisions in situations of uncertainty.
When to use it
Investment decisions: Investors might overestimate the probability of a stock market crash after hearing recent news about a downturn (availability), leading to panic selling.
Hiring: Interviewers may rely on representativeness, favoring candidates that match a stereotypical 'ideal employee' rather than evaluating statistical evidence of job performance.
Pricing strategy: Retailers can set a high anchor price for a product to make a later discounted price seem like a great deal, influencing consumers' willingness to pay.
FROM THEORY TO EVERYDAY LIFE
In practice
Representativeness Heuristic Example
A person described as shy and fond of reading may resemble a librarian stereotype. If farmers are more common than librarians in the relevant population, that base rate also matters when judging the person’s occupation. Resemblance alone is not enough.
Anchoring Heuristic Example
In real estate appraisals, an initial price listing can anchor the perceived value of a home. Even if the listing is arbitrary, subsequent estimates tend to be adjusted insufficiently from that anchor, leading to biased valuations.
A MOMENT TO REFLECT
Put it to work.
Think of a recent decision you made based on how easily examples came to mind (availability). How might that have been influenced by media or personal experience?
Consider a time when you judged someone's character based on a quick assessment. Could the representativeness heuristic have played a role?
When negotiating or estimating numbers, were you influenced by an initial anchor? How could you use alternative anchors to improve your judgment?
CONTINUE THE CONVERSATION
Source texts
- Thinking, Fast and Slow (Daniel Kahneman)