The Availability Bias (or Availability Heuristic) is a mental shortcut that affects our judgment and decisions based on how easily we can think of examples.
It works on the notion “if you can think of it, it must be important.”
We tend to most easily recall what is salient, important, frequent and recent. First-hand experience is more available than what has happened to others, but the media heavily skews availability.
The availability bias is likely one of the brain’s automatic energy-saving mechanisms and, as a result, we have little control over this tendency.
3 things you should know about the availability bias:
- We often misjudge the frequency and magnitude of events that have happened recently.
- This happens, in part, because of the limitations on memory.
- Vivid narratives are easier to remember.
Because of availability bias, we misjudge risk and tend to worry about the wrong risks, often with disastrous consequences.
We make decisions based on what we remember. This is influenced by beliefs, expectations, emotions, feelings and frequency of exposure. Media makes a big difference. It covers rare events heavily (and often vividly), making it easy for us to recall the event. This leads to a tendency to overestimate both the frequency and impact of that particular event.
The rarer, more vivid and more impactful the event, the more likely we overweigh it.
A good example of this is any man-made disaster:
- When a major car accident happens, especially if we’re involved in it, on our usual road to work, we become more vigilant the next time we drive there.
- When we hear of an airplane crash, we start overestimating the likelihood of airplane accidents. We might even avoid that particular airline or flight route because of this.
Recalling an event and its actual probability, however, are two separate things.
Herbert Simon, Nobel Prize-winning social scientist and father of Artificial Intelligence wrote in Models of My Life:
“I soon learned that one wins awards mainly for winning awards: an example of what Bob Merton calls the Matthew Effect. It is akin also to the phenomenon known in politics as “availability,” or name recognition. Once one becomes sufficiently well known, one’s name surfaces automatically as soon as an award committee assembles.”
Availability bias also lays the foundation for the illusory-correlation effect: the strength of the association between two events affects our judgment of how frequently the two events co-occur. We consider strong associations to occur together frequently.
Some research examples:
- “If a random word is taken from an English text, is it more likely that the word starts with a K, or that K is the third letter?” (Tversky & Kahneman)
- Most people guess the former, while the latter is actually more likely. The former is, however, easier to recall and requires less mental effort.
- “In 5 seconds, what is the estimated result of 1x2x3x4x5x6x7x8? And what of 8x7x6x5x4x3x2x1?” (Tversky & Kahneman)
- In general, when estimating anything, we tend to underestimate the end result, especially if the problem consists of multiple steps. Projects are rarely completed faster and cheaper than expected, but, instead, are often delayed and more expensive.
- Anchoring: how information is presented (availability) affects our estimate. In the above example, both groups underestimated the end result, but the first calculation led to a much greater underestimation than the second. We base our estimate on our initial impression, particularly when under stress. This anchoring bias affects everyone, including experts.
- “Recall six examples of your assertive or unassertive behaviour.” vs “Recall twelve examples of your assertive or unassertive behaviour.” (Schwarz et al.)
- After doing the above exercise, when participants were asked to rate their own assertiveness, the former group rated themselves as more assertive, while the latter rated themselves as less assertive.
- This study shows that the ease of recall (6 vs 12 examples) affects our judgment more so than the number of examples we remember.
Pairing the availability bias with incentives can lead to availability cascades or a media feeding frenzy: a self-reinforcing cycle whereby a novel idea or insight that explains a complex process in a simple manner displaces an old belief.
Because of its simplicity and apparent insight, it gains popularity, which triggers a chain reaction in social networks: new people accept it because others have done so. The desire to fit in with the group and the apparent utility of the insight overwhelms our critical thinking.
People and organisations in power, together with the media, often use this mechanism to change public opinion or discredit competitors.
There is no foolproof way to prevent availability bias, anchoring or availability cascades, but here are some ways that can reduce their impact:
- Maintain a clean environment. Avoid most, if not all, news. Focus on timeless wisdom over temporary knowledge.
- Differentiate between signals and noise.
- Signals: Major events or longer-term major trends that are vastly different from the norm. Example: water levels rising annually.
- Noise: Tiny, temporary changes that can be expected and will revert back to the mean. Example: the stock market went up/down 1%.
- Compare your estimate with historical and recent data. While unable to predict, beware Black Swans (outlier events).
- Create your own checklist to (1) help you with important decisions or (2) reflect on your recent actions, well-being and performance.
Availability Heuristic examples
With disasters (natural, man-made, financial), when they occurred recently and are made vivid, we tend to overestimate their frequency.
Recent natural disasters that have destroyed homes lead to an increase in purchased home insurances during the aftermath.
News of people drowning at sea does little to change people’s behaviour. Reports of shark attacks make people avoid those waters.
With war, when we read reports of large numbers of people being killed, we fear the magnitude but it does little to change our behaviour. A picture of a child without a mother, however, becomes a rallying cry and changes both perception and action.
1000 people is a statistic, 1 crying child is a (vivid) story.
With investing, Bitcoin or stocks being up 50% on the year means the sky is the limit. Them being down 50% means it’s all a scam, time to panic and keep cash at home.
In business, we want our brand to show up often and be associated with positive emotions or inspiring role models. This exposure leads to easier recall and a more positive impression of that brand, leading to more sales. It also works in reverse (negative associations lead to negative impressions).
A positive example: Nike being associated with “great” athletes. We all want to “be like Mike”.
A negative example: companies caught in scandals (financial institutions) or recalling products due to defects (car companies).
This is an example of Availability Bias in combination with Mere Association Bias & Mere Exposure Effect.
With performance evaluation and reputation, even if we’ve done many good things, we are often judged by our most recent mistake, especially if it was more recent than a major accomplishment.
Similarly, we judge more based on recent performance than on past performance, despite a long track record and the cause being randomness.
Not convinced? Look at how we judge (and feel about) athletes and sports teams after a loss.
In social life, someone who has been honest for years and recently lied is a liar. On the other hand, someone who lied in the past but has been honest recently is an honest man.
In life, we make many purchase decisions based on availability bias, especially if it’s something we rarely buy. With a rare purchase, whichever brand or company comes to mind is likely the one we’ll go with.
The same applies to (spontaneous) dates: when deciding on locations or restaurants we’ll likely go with whatever comes to mind first. Unless you dedicate time to research, of course.
With studying, you can use availability bias to your advantage. Remember: We tend to most easily recall what is salient, important, frequent and recent, and we remember first-hand experiences and stories better than random pieces of information.
When you want to remember something:
- Create vivid memory palaces
- Go through the same material multiple times.
- Space the learning over multiple sessions and use spaced repetition software.
- Imagine it as a movie scene. The more senses (smell, sound, etc) you can engage, the better.