The Availability Heuristic

It is the tendency to judge how common or likely something is by how easily examples of it come to mind. Studies from lists of famous names to flood insurance find the effect again and again, and the feeling of ease is itself a clue: people asked for many examples can end up judging a quality rarer than people asked for a few. A pooled review of 263 studies finds a medium sized effect, and asking where your examples came from, then checking the counts, is the most reliable safeguard.

What the report found

1. Ease of recall stands in for frequency. People asked how common something is answer partly by how easily examples come to them, and easy examples make things seem more common.
2. The feeling of ease matters, not only the examples. People asked for six examples of their own assertive behaviour rated themselves as more assertive than people asked for twelve, though the second group recalled more.
3. It reaches into everyday choices. Imagining an outcome made it seem likelier, asking for many reasons made a product seem less appealing, one repeated voice made an opinion seem widely held, and insurance take up rose after a nearby flood, then faded.
4. It is real, and more selective than the textbook version suggests. A pooled review of 263 studies found a medium sized effect, partly carried by felt ease and partly by other routes.
5. Not every use of availability is an error. Examples from people's own lives often track real frequencies well, and researchers still debate how far media coverage distorts judgement. Asking where your examples came from, and checking the counts, is the best safeguard.

What is inside

1. The idea and where it came from
2. The original studies, explained
3. What happened when others tested it
4. Where researchers disagree
5. What we can say with confidence

Plus a timeline of the key studies, three debates set out side by side and a table grading each common claim.

Who it is for

For marketers and communicators, researchers who run surveys, anyone who explains risk, and anyone who wonders why the story they heard last week feels so common.

How we work

Evidence Reviews follow one well known idea from its origin to today: the original studies, what happened when others tested them, where researchers disagree and what we can say with confidence. Every claim is graded, and both sides of each debate are set out before we say where we stand.

Cite this report

The Why We Project (2026) The Availability Heuristic: Why vivid examples feel common. Evidence Review No. 21. Dubai: Why We Tech Ltd. Available at: thewhyweproject.com