What Is an Availability Heuristic?

This mental shortcut can lead to fast decisions and (sometimes) bad judgments

A girl thinking and making a decision
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Which job is more dangerous - being a police officer or a logger? While high profile police shootings might lead to you think that cops have the most dangerous job, statistics actually show that loggers are more likely to die on the job than cops. When it comes to making this type of judgment about relative risk or danger, our brains rely on a number of different strategies to make quick decisions.

This illustrates what is known as the availability heuristic, a mental shortcut that helps you make fast, but sometimes incorrect, assessments.

There are all kinds of mental shortcuts, but one common one involves relying on information that comes to mind quickly. This is known as the availability. If you can quickly think of multiple examples of something happening – such as police shootings – you will believe that it is more common.

How Does the Availability Heuristic Work?

When you are trying to make a decision, a number of related events or situations might immediately spring to the forefront of your thoughts. As a result, you might judge that those events are more frequent or probably than others. You give greater credence to this information and tend to overestimate the probability and likelihood of similar things happening in the future.

For example, after seeing several news reports about car thefts, you might make a judgment that vehicle theft is much more common than it really is in your area.

This type of availability heuristic can be helpful and important in decision-making. When faced with a choice, we often lack the time or resources to investigate in greater depth. Faced with the need to an immediate decision, the availability heuristic allows people to quickly arrive at a conclusion.

This can be helpful when you are trying to make a decision or judgment about the world aroud you. For example, would you say that there are more words in the English language that begin with the letter t or with the letter k. You might try to answer this question by thinking of as many words as you can that begin with each letter. Since you can think of more words that begin with t, you might then believe that more words begin with this letter than with k. In this instance, the availability heuristic has let you to a correct answer.

In another example, researchers have found that people who are more easily able to recall seeing antidepressant advertising were also more likely to give high estimates about the prevalence of depression.

This Can Sometimes Lead to Incorrect Decisions

Like other heuristics, the availability heuristic can be useful at times. However, it can lead to problems and errors. Reports of child abductions, airplane accidents, and train derailments often lead people to believe that such events are much more typical than they truly are.

The term was first coined in 1973 by Nobel-prize winning psychologists Amos Tversky and Daniel Kahneman. They suggested that the availability heuristic occurs unconsciously and operates under the principle that "if you can think of it, it must be important." Things that come to mind more easily are believed to be far more common and more accurate reflections of the real world.

As Tversky and Kahneman explained, one of the most obvious examples of the availability heuristic in action is the impact of readily available examples. For example, after you see a movie about a nuclear disaster, you might become convinced that a nuclear war or accident is highly likely. After seeing a car overturned on the side of the road, you might believe that your own likelihood of getting in an accident is very high. And the longer you stay preoccupied with the event, the more available it will be in your mind and the more probable you will believe it to be.

The problem is that certain events tend to stand out in our minds more than others.

Excessive media coverage can cause this to happen, but sometimes the novelty or drama surrounding an event can cause it to become more available in your memory. Because the event is so unusual, it takes on greater significance, which leads you to incorrectly assume that the event is much more common than it really is.

Examples of the Availability Heuristic

  • After seeing news reports about people losing their jobs, you might start to believe that you are in danger of being layed-off. You start lying awake in bed each night worrying that you are about to be fired.
  • After seeing several television programs on shark attacks, you start to think that such incidences are relatively common. When you go on vacation, you refuse to swim in the ocean because you believe the probability of a shark attack is high.
  • After reading an article about lottery winners, you start to overestimate your own likelihood of winning the jackpot. You start spending more money than you should each week on lottery tickets.
  • After seeing news stories about high-profile child abductions, you begin to believe that such tragedies are quite common. You refuse to let your child play outside by herself and never let her leave your sight.  

A Word From Verywell

Heuristics play an important role in how we make decisions and act upon information in the world around us. The availability heuristic can be a helpful tool, but it is also important to remember that it can sometimes lead to incorrect assessments. Just because something looms large in your memory does not necessarily mean that it is more common, so it can be helpful to rely on numerous tools and decision-making strategies when you are trying to make a choice.

Sources:

An, S. Antidepressant direct-to-consumer advertising and social perception of the prevalence of depression: Application of the availability heuristic. Health Communication. 2008; 23(6): 499-505.

Bureau of Labor Statistics. Revisions to the 2014 Census of Fatal Occupational Injuries. 2016.

Medin, DL & Ross, BH. Cognitive Psychology. New York: Wiley; 2004.

Tversky, A & Kahneman, D. Availability: A Heuristic for Judging Frequency and Probability. Cognitive Psychology. 1973; 5(1): 207-233.

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