What is the Availability Heuristic?
The availability heuristic is a cognitive bias that causes people to rely too heavily on easily accessible memories when estimating probabilities and making decisions. This mental shortcut can distort our perception of how frequently certain events occur.
A classic example of the availability heuristic is believing that airplanes are unsafe because of highly publicized plane crashes. This bias contradicts statistical evidence showing that flying is a much safer mode of transportation than driving.
Have you ever made a decision based on information that was readily available in your memory? If so, you may have fallen prey to the availability heuristic.
The availability heuristic is a mental shortcut that our brains use to evaluate probabilities quickly. When we face a decision, we tend to rely on information that comes to mind easily. This includes information we can recall more easily, events that affected us strongly, and recent events.
Unfortunately, this cognitive bias distorts our ability to judge the probability of certain events accurately. Our memories frequently are not realistic models for forecasting future outcomes.
For example, imagine estimating the likelihood of a car accident on your daily commute. Your brain might rely on readily accessible information, such as past experiences or media coverage, rather than statistical data, leading to inaccurate estimates.
Learn more about Cognitive Biases.
Availability Heuristic Examples
Some examples of the availability heuristic include:
- Assuming that all sharks are dangerous and that shark attacks are common because of media coverage of shark attacks. In reality, the vast majority of shark species are not harmful to humans. Indeed, there were only 57 confirmed shark attacks worldwide in 2022.
- Overestimating the risk of being a victim of a terrorist attack. Statistically, the likelihood of being killed in a terrorist attack is extremely low.
- Assuming that all large dogs are aggressive and dangerous because of news stories or personal experiences with them.
How the Availability Heuristic Works
Psychologists Amos Tversky and Daniel Kahneman coined the term “availability heuristic” in 1973. They suggested that it operates subconsciously and uses the principle, “If you can think of it, it must be important.” This notion leads people to believe that things that come to mind more quickly are more common.
The availability heuristic is based on ease of retrieval. The more easily accessible information is, the more likely people are to rely on it to evaluate probabilities and make decisions. Media coverage, recency, and the unavailability of information can foster the availability heuristic.
One of the main reasons the availability heuristic occurs is due to media coverage. When news outlets or social media expose us to particular events, they become more salient in our minds. For example, if we hear about a plane crash, we may become more fearful of flying, even though flying is one of the safest modes of transportation.
Sensationalized news stories such as reports of shark attacks, plane crashes, and child abductions instigate fear. Incidents of this magnitude are splashed all over the media and can create hysteria. This media coverage leads us to believe these catastrophes are more common than they are.
Recency is another factor that can influence the availability heuristic. When something has happened recently, it is more likely to be at the forefront of our minds. For example, if you have just seen a car accident on your way to work, you might be more likely to take a different route, even though the accident is uncommon.
The unavailability of information can also contribute to the availability heuristic. When we cannot access certain information, we must rely on what we know, even if it is incomplete or inaccurate. For example, imagine trying to estimate the percentage of people in your country who are immigrants. You might rely on your personal experiences and interactions, even though they probably don’t represent the overall population.
Awareness of this bias can help us make more informed decisions and avoid judgments based on incomplete or inaccurate information. And keep in mind that it’s not just what you know but the subset that comes to mind quickly.
Amos Tversky, Daniel Kahneman, Availability: A heuristic for judging frequency and probability, Cognitive Psychology, Volume 5, Issue 2, 1973, Pages 207-232, https://doi.org/10.1016/0010-0285(73)90033-9.