This Thursday, January 15th, 2009, US Airways Flight 1549 landed in the Hudson River. The crash was very widely publicized by the US press. I would like to mention one interesting phenomenon that might affect cognition of people after this event.

Psychologists Amos Tversky and Daniel Kahneman (Nobel laureate) showed that people often estimate probability using heuristics to ease judgment.

Availability Heuristic

There are situations in which people assess the frequency of a class or the probability of an event by the ease with which instances or occurrences can be brought to mind. For example, one may assess the risk of heart attack among middle-aged people by recalling such occurrences among one’s acquaintances. Similarly, one may evaluate the probability that a given business venture will fail by imagining various difficulties it could encounter.

Thus, witnessing a crash or watching about it on TV may make some people think that the occurrence of such an event is more likely than it is. Probability of a fatal plane crash is quite remote: 1 in 1 million to 10 million depending on the airline (1, 2) – you are much more likely to die from heart disease (start exercising now). Don’t let the media intimidate you!

14 thoughts on “Availability Heuristic and Cognitive Bias

  1. The problem with that sort of thinking is that it happens moreso with bad events than good events. So I don’t think it’s the media being intimidating, just people being naturally negative.

    1. It happens with both negative and positive events. The key is ease of retrieval of an example. Ross and Sicoly (1979) reported that both husbands and wives claimed greater responsibility than their spouse for 16/20 household activities 😛 Our own activity is more readily available for recall than the activity of others.

      If you want an example related to politics, participants who were asked to imagine Gerald Ford or Jimmy Carter winning the upcoming US Presidential Election 1976 subsequently viewed the candidate they imagined winning as being significantly more likely to win the upcoming election! 🙂 Similarly, given the extensive coverage by the media, an event such as a plane crash may be more easily recalled and influence our estimate.

  2. It happens with both bad and good yes, but we are more likely to only remember the bad events that are widely publicized all the time, because we see it being reported, and we have an innate fear of being in the same situation. Survival instinct, if you will.

  3. …From personal experience, the things I remember most are usually the bad things… D=

    In some cases, then, the availability heuristic is dependent on whether or not a person is a pessimist or an optimist. If someone asked me to imagine a candidate winning, my mind wanders off to all the negative possibilities instead, to the point where I might even imagine said candidate to end up a hobo on the street.

    ……This is probably why I stopped watching local news.

  4. Panther,

    Yes, fear is a powerful influence. Sometimes, instead of thinking that something bad will happen, people go into denial, thinking it will never happen to them.

    – – –


    I see. The bias resulting from availability heuristic might be influenced by some individual differences. Some studies failed to find such differences in use of heuristics, but they might not have measured pessimistic attitudes. It does seem reasonable that a negative attitude can affect judgment.

    Another similar case is a simulation heuristic that is “based on the ease with which self generated fictitious examples can be mentally simulated or imagined.”

    Yes, I don’t watch local news as well…

  5. Humans are notorious at overestimating. They overestimate their own intelligence, their own likelihood of exhibiting a certain behavior, and yes, the likelihood of an exceedingly rare event occurring.

    I think people are nature’s little overachievers…well, at least we think we are.

    1. Indeed, we overestimate many things, but, sometimes, we underestimate as well. For example, people tend to overestimate how much they can accomplish in short-term compared to long-term. If you do something every day, it adds up quickly 🙂

  6. excuse my ignorance but if probability of a fatal plane crash is one in one to ten million, what would the probability of one happening the same day the next year be?

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