---
title: Availability heuristic
url: https://propagandaarchive.org/learn/availability-heuristic/
description: The availability heuristic is the habit of judging how common or likely something is by how easily examples come to mind.
section: Learn
---

![Illustration: an interwar radio-and-newsreel intelligence collage with a 1930s map of Europe and propaganda poster proofs.](https://propagandaarchive.org/static/generated/detail/hero-interwar.jpg)

[Learn](https://propagandaarchive.org/learn/) · Cognitive biases and heuristics

# Availability heuristic

In brief

People judge how common something is by how easily examples come to mind, so vivid, recent or heavily covered events feel more frequent; ease of recall is well supported, though one classic demonstration is disputed.

On this page

- [In brief](https://propagandaarchive.org/learn/availability-heuristic/#in-brief)
- [What the research shows](https://propagandaarchive.org/learn/availability-heuristic/#what-the-research-shows)
- [Has it held up?](https://propagandaarchive.org/learn/availability-heuristic/#has-it-held-up)
- [How it shows up in political messaging](https://propagandaarchive.org/learn/availability-heuristic/#how-it-shows-up-in-political-messaging)
- [How to spot it](https://propagandaarchive.org/learn/availability-heuristic/#how-to-spot-it)
- [Persuasion or manipulation?](https://propagandaarchive.org/learn/availability-heuristic/#persuasion-or-manipulation)
- [Archive techniques that lean on this](https://propagandaarchive.org/learn/availability-heuristic/#archive-techniques-that-lean-on-this)
- [Related topics](https://propagandaarchive.org/learn/availability-heuristic/#related-topics)
- [Sources](https://propagandaarchive.org/learn/availability-heuristic/#sources)
- [Images](https://propagandaarchive.org/learn/availability-heuristic/#images)

On this page

*Area: [Cognitive biases and heuristics](https://propagandaarchive.org/learn/cognitive-biases/) · Evidence:**moderate**([How we rate the evidence](https://propagandaarchive.org/learn/evidence-ratings/)). Ease of recall reliably shapes judgments in experiments, but one classic demonstration has been disputed, and the link from news coverage to public risk estimates rests mostly on correlational evidence.*

## In brief

The availability heuristic is the habit of judging how common or likely something is by how easily examples come to mind. It is often a sensible shortcut, since frequent things are usually easy to recall. It misleads when something is memorable for reasons other than frequency: because it was vivid, recent, dramatic or heavily covered. Political messages that keep a particular danger or a particular kind of wrongdoer in view are, among other things, making it more available.

## What the research shows

Tversky and Kahneman named the heuristic in 1973 [1]. In one study they read participants a list of names that included either more men or more women, with the less numerous sex represented by more famous people. Most participants then judged that the list contained more of the famous sex, because those names were easier to recall. In another, people judged that more English words begin with the letter K than have K in the third position, which the authors attributed to the ease of calling words to mind by their first letter.

Sarah Lichtenstein, Paul Slovic and colleagues asked people to estimate how often various causes of death occur in the United States [2]. Two kinds of error appeared. People overestimated rare causes and underestimated common ones, and, at any given true frequency, they overestimated dramatic, sensational causes (such as botulism, tornadoes, floods and homicide) and underestimated quiet ones (such as diabetes, stroke and stomach cancer). Barbara Combs and Slovic then counted how two daily newspapers covered causes of death [3]. The papers overreported violent and catastrophic deaths and underreported disease, and the pattern of coverage closely matched the pattern of the public's misjudgments.

Norbert Schwarz and colleagues showed that it is the felt ease of recall, and not only what is recalled, that people use [4]. Participants listed either 6 or 12 examples of their own assertive behavior. Listing 12 was hard, and those participants rated themselves as less assertive than people who listed 6, even though they had just produced twice as many examples. The difficulty itself was taken as evidence.

## Has it held up?

The general finding that ease of retrieval influences judgment has substantial support. A 2018 meta-analysis by Evan Weingarten and J. Wesley Hutchinson pooled 263 studies using the Schwarz-style "list a few or many" method and found a medium-sized effect on judgments [5]. It also asked whether subjective ease is what carries the effect, and found the evidence on that question less clear-cut than the effect itself.

Some of the original demonstrations have been challenged. Peter Sedlmeier, Ralph Hertwig and Gerd Gigerenzer repeated the letter-position task with a wider set of letters and did not find the systematic bias the availability account predicts [6]. The link between media coverage and public risk estimates is also weaker than it is often presented. Combs and Slovic showed that coverage and judgments moved together, not that coverage caused the judgments; people may also overestimate dramatic risks for other reasons, including how much they fear them. For these reasons the page rates the evidence as moderate rather than strong.

## How it shows up in political messaging

- **"Remember Belgium," WWI.** A British recruiting poster showed a soldier guarding a woman and child fleeing a burning village, keeping the 1914 invasion of Belgium in view [Remember Belgium — Enlist To-Day](https://propagandaarchive.org/collection/remember-belgium-1915/). The word "remember" asks directly for an event to stay mentally available.

![British recruiting poster showing a soldier in front of a woman and child fleeing a burning village](https://propagandaarchive.org/collection/images/remember-belgium-1915.jpg)

*"Remember Belgium: Enlist To-Day," Parliamentary Recruiting Committee (United Kingdom) poster, 1915. From the FRAME gallery: [Remember Belgium — Enlist To-Day](https://propagandaarchive.org/collection/remember-belgium-1915/)*

- **"Daisy," 1964.** Lyndon Johnson's campaign ran an advertisement in which a girl counting petals gives way to a countdown and a nuclear explosion, aimed at Barry Goldwater's statements on nuclear weapons [7]. It aired once as a paid spot but was replayed widely in news coverage, turning an abstract risk into a vivid image.

![Frame from the 1964 Johnson campaign advertisement showing a girl pulling petals from a daisy](https://propagandaarchive.org/collection/images/daisy-ad-1964.jpg)

*Frame from "Peace, Little Girl" ("Daisy"), Lyndon B. Johnson presidential campaign, broadcast 7 September 1964. From the FRAME gallery: [Peace, Little Girl ("Daisy")](https://propagandaarchive.org/collection/daisy-ad-1964/)*

- **Willie Horton, 1988.** An independent committee supporting George H. W. Bush ran "Weekend Passes," built around one man who committed violent crimes while on furlough from a Massachusetts prison under Michael Dukakis; the Bush campaign's own "Revolving Door" ad attacked the furlough program in general [8]. A single, vivid case stood in for a judgment about the whole program.
- **Terror alerts after 2001.** The color-coded Homeland Security Advisory System kept a national threat level on public display for nine years without base rates or specific guidance [Homeland Security Advisory System threat-level chart](https://propagandaarchive.org/collection/homeland-security-advisory-system-2002/). Gigerenzer estimated that in the three months after September 11, about 350 more people than expected died on American roads, deaths he attributed to people driving instead of flying, and more than the number of passengers killed on the four hijacked planes [9]. A highly available risk can displace a larger, less memorable one.

![Five-color Homeland Security Advisory System threat-level scale](https://propagandaarchive.org/collection/images/homeland-security-advisory-system-2002.svg)

*Homeland Security Advisory System five-color threat-level scale, U.S. Department of Homeland Security, in use 2002 to 2011. From the FRAME gallery: [Homeland Security Advisory System threat-level chart](https://propagandaarchive.org/collection/homeland-security-advisory-system-2002/)*

- **Germany after Fukushima, 2011.** Months after extending the lives of its nuclear plants, Angela Merkel's center-right government reversed course following the Fukushima disaster in Japan and committed to closing all German reactors by 2022, citing a new assessment of the risks [10]. The timing shows how a single vivid event can reset a long-running risk debate.

## How to spot it

- One case, image or story is offered where the question is about a rate.
- A message asks the audience to "remember" or "imagine" rather than to compare numbers.
- Coverage of a risk rises sharply while its measured frequency has not changed.
- Dramatic harms are described at length and common, slow harms are absent.
- A useful check is to ask for the denominator: how many cases, out of how many, compared with what.

## Persuasion or manipulation?

Using a real, representative example to make a statistic understandable is good communication, and reminding people of a documented event is not deceptive. It becomes manipulation when the example is chosen because it is unrepresentative, when repetition of rare cases is used to create an impression of frequency the data do not support, or when the base rate is withheld so that the audience cannot tell whether the vivid case is typical. Honest material pairs the story with the numbers.

## Archive techniques that lean on this

- [Fear appeal](https://propagandaarchive.org/techniques/fear-appeal/) — Fear appeal: a vivid, easily imagined harm feels more likely than its base rate warrants, which gives the prescribed remedy its urgency.
- [Card stacking](https://propagandaarchive.org/techniques/card-stacking/) — Card stacking: selecting memorable cases and omitting the denominator lets availability do the rest.

## Related topics

- [Base-rate neglect](https://propagandaarchive.org/learn/base-rate-neglect/) — Base-rate neglect
- [Negativity bias](https://propagandaarchive.org/learn/negativity-bias/) — Negativity bias
- [Identifiable victim effect](https://propagandaarchive.org/learn/identifiable-victim-effect/) — Identifiable victim effect
- [Fear messaging](https://propagandaarchive.org/learn/fear-messaging/) — Fear messaging
- [Affect heuristic](https://propagandaarchive.org/learn/affect-heuristic/) — Affect heuristic
- [Anchoring](https://propagandaarchive.org/learn/anchoring/) — Anchoring

## Sources

1. Tversky, A., & Kahneman, D. (1973). Availability: A heuristic for judging frequency and probability. *Cognitive Psychology*, 5(2), 207–232. https://doi.org/10.1016/0010-0285(73)90033-9
2. Lichtenstein, S., Slovic, P., Fischhoff, B., Layman, M., & Combs, B. (1978). Judged frequency of lethal events. *Journal of Experimental Psychology: Human Learning and Memory*, 4(6), 551–578.
3. Combs, B., & Slovic, P. (1979). Newspaper coverage of causes of death. *Journalism Quarterly*, 56(4), 837–849. https://doi.org/10.1177/107769907905600420
4. Schwarz, N., Bless, H., Strack, F., Klumpp, G., Rittenauer-Schatka, H., & Simons, A. (1991). Ease of retrieval as information: Another look at the availability heuristic. *Journal of Personality and Social Psychology*, 61(2), 195–202.
5. Weingarten, E., & Hutchinson, J. W. (2018). Does ease mediate the ease-of-retrieval effect? A meta-analysis. *Psychological Bulletin*, 144(3), 227–283. https://doi.org/10.1037/bul0000122
6. Sedlmeier, P., Hertwig, R., & Gigerenzer, G. (1998). Are judgments of the positional frequencies of letters systematically biased due to availability? *Journal of Experimental Psychology: Learning, Memory, and Cognition*, 24(3), 754–770.
7. Museum of the Moving Image. "Peace, Little Girl (Daisy)," 1964. *The Living Room Candidate*. https://www.livingroomcandidate.org/commercials/1964/peace-little-girl-daisy
8. Museum of the Moving Image. "Willie Horton" and "Revolving Door," 1988. *The Living Room Candidate*. https://www.livingroomcandidate.org/commercials/1988/willie-horton ; https://www.livingroomcandidate.org/commercials/1988/revolving-door
9. Gigerenzer, G. (2004). Dread risk, September 11, and fatal traffic accidents. *Psychological Science*, 15(4), 286–287. https://doi.org/10.1111/j.0956-7976.2004.00668.x
10. Clean Energy Wire. The history behind Germany's nuclear phase-out. https://www.cleanenergywire.org/factsheets/history-behind-germanys-nuclear-phase-out ; see also Al Jazeera. (2011, May 30). Germany pledges nuclear shutdown by 2022. https://www.aljazeera.com/amp/news/2011/5/30/germany-pledges-nuclear-shutdown-by-2022

## Images

| Image | Source | Licence |
| --- | --- | --- |
| *Remember Belgium: Enlist To-Day* (1915) | FRAME gallery, [Remember Belgium — Enlist To-Day](https://propagandaarchive.org/collection/remember-belgium-1915/); Library of Congress LC-USZC4-11071 | Public domain (published before 1923) |
| "Daisy" advertisement frame (1964) | FRAME gallery, [Peace, Little Girl ("Daisy")](https://propagandaarchive.org/collection/daisy-ad-1964/) | Public domain (published without a copyright notice, per Wikimedia Commons) |
| Homeland Security Advisory System scale (2002) | FRAME gallery, [Homeland Security Advisory System threat-level chart](https://propagandaarchive.org/collection/homeland-security-advisory-system-2002/) | Public domain (U.S. government work) |

## Techniques

[Fear appeal](https://propagandaarchive.org/techniques/fear-appeal/) [Card stacking](https://propagandaarchive.org/techniques/card-stacking/)

## Related

- [Anchoring](https://propagandaarchive.org/learn/anchoring/)
- [Base-rate neglect](https://propagandaarchive.org/learn/base-rate-neglect/)
- [Negativity bias](https://propagandaarchive.org/learn/negativity-bias/)
- [Fear messaging](https://propagandaarchive.org/learn/fear-messaging/)
- [Identifiable victim effect](https://propagandaarchive.org/learn/identifiable-victim-effect/)
- [Affect heuristic](https://propagandaarchive.org/learn/affect-heuristic/)
- [Fear appeal](https://propagandaarchive.org/techniques/fear-appeal/)
- [Card stacking](https://propagandaarchive.org/techniques/card-stacking/)