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This page was translated from the German original, partly by machine. Some passages may read awkwardly or contain inaccuracies. When in doubt, please read the original.

Availability Heuristic

In short

What is close at hand seems more probable.

What I don't know won't hurt me.

Definition​

The availability heuristic is a mental shortcut in which people estimate the probability of events based on how easily examples of them come to mind.

It is easier for us to recall readily available information and to take it into account in decisions. (cognitive ease)

DE: Verfügbarkeitsheuristik

The availability heuristic is closely connected to several other biases and is reinforced by them:

  • Salience bias: What is especially striking, emotional or visually conspicuous is more easily retrieved — and thereby seems "more important".
  • Recency effect: Recently experienced or seen information is especially available and shapes judgments disproportionately.
  • Negativity bias: Negative events stick in memory better, which leads risks to be systematically overestimated.
  • Confirmation bias: We above all seek and remember examples that support our beliefs — and those then become especially available.
  • Survivorship bias: Only the visible "success stories" are present; the invisible failures are missing from the mental data set.
  • Representativeness heuristic: Vivid, stereotypical examples are wrongly taken to be typical; availability and representativeness influence each other.
  • Recall bias: Systematic errors in remembering (e.g. in studies) amplify the apparent frequency of certain events.

Examples​

Plane Crashes​

The vast majority of us have never experienced a plane crash. But whenever a plane crashes somewhere in the world, it is reported on intensively. As a result, people overestimate the risk of dying in a plane crash, even though it is far more likely to die in a car accident.

Violent Crime​

People overestimate the frequency of violent crime when they have recently watched a thriller, when it is reported in the media, or — worse — when they themselves have become a victim or witness of violence. Scary things also stay in memory longer. In this way the probability of violent crime is overestimated.

Repetition makes the brand available to the brain​

Those who see or hear a brand or product often remember it more easily and judge it to be better known and more trustworthy, even when the quality is no better. This also works very well in politics. If you repeat a stupid idea over and over, it becomes available to many people and thereby seems more plausible.

Effects​

  • Distorted risk perception
  • Overestimation of rare but dramatic events
  • Underestimation of common but less conspicuous risks

Counter-Strategies​

  • On important questions, you should look for statistical data rather than anecdotal evidence.
  • We should all develop awareness of the influence of media coverage on our own perception.
  • Systematically record events instead of relying on memory.

Sources​