principlebeginnerconcrete

Availability Heuristic

Judging the frequency or probability of events by how easily examples come to mind, leading to overestimation of vivid, recent, or emotional events.

In Depth

System 1 assesses frequency by ease of recall: if examples come easily to mind, we assume the category is common. This works when memorable events are actually frequent, but fails when vivid, recent, or emotional events are overrepresented in memory. After seeing news coverage of plane crashes, people overestimate aviation risk and choose to drive instead, even though driving is statistically more dangerous. The heuristic makes us vulnerable to media-driven panics and explains why we overestimate dramatic risks while underestimating mundane ones.

Example

Doctors who recently saw a rare disease diagnose it more frequently in subsequent patients. People overestimate terrorism risk after media coverage but underestimate heart disease risk despite it being far more common.

Common Misconception

If you can easily think of examples, the event must be common—in reality, ease of recall reflects memorability (vividness, recency, emotion) not actual frequency.

Source

Thinking, Fast and Slow

Daniel Kahneman

cognitive psychologyrisk assessmentdecision-making

Related Concepts

builds on

System 1 Thinking

Fast, automatic, unconscious cognitive processing that operates through pattern recognition and associative memory without deliberate effort.

builds on

Base Rate Neglect

Ignoring statistical base rates (how common something is in the population) in favor of specific case information or stereotypes.

Test Your Understanding

active recallmedium

Why does the availability heuristic lead to overestimation of dramatic risks like terrorism while underestimating mundane risks like heart disease?

true false nuancedeasy

True or False: If you can easily think of examples of something, it's probably common.