The Availability Heuristic ‘A mental shortcut in which one judges a phenomenon to be more frequent or more likely to occur when memories of it are easily retrieved’ (Sc.Maricopa.edu, 2003). Errors occur when rare instances are vivid and easily brought to mind, for example shark attacks, plane crashes. The following question was asked: ‘Do more people die each year from being hit by falling aeroplane parts or from shark attacks?’ Most people would immediately answer shark attacks, but this answer is wrong. ‘In an average year in the United States 30 times more people are killed by falling aeroplane parts than by shark attacks’ (Ruscio, 2002, p.111). The influence of the availability heuristic is being used in this example. From the definition of the availability heuristic it can be explained that shark attacks, when they occur, are publicized widely on television news and have been immortalized in popular movies such as Jaws, it is then easy for people to bring instances of them in to their minds. But, because people have probably never heard or seen of anyone being hit by a falling aeroplane part, memories of deaths caused by this event are not mentally available to you. Information gathered about memory would suggest that four factors are important for making an event memorable and, therefore easy to bring to mind. Firstly, events that are easily perceived by the senses (concrete) are more memorable than events that are not. For example, it’s probably easier to form a memory of a chair than it is to form the memory of the meaning of the concept of determinism. A chair is a highly concrete object that can easily be imagined whereas determinism is not something that can be perceived by the senses and, therefore cannot be imagined. Secondly, by having events that have a personal relevance they are more likely to be remembered. Making information personally meaningful improves retrieval of the information in future.
By having events that are associated with emotion, they are made more memorable than those that are not. Strong emotions such as those of happiness or fear can tend to lead to the development of enduring memories.
Events that occur repeatedly are more memorable than those that occur on rare occasions. For example if you listen to a song several times you are more likely to remember it than if you just hear it once.
Representativeness heuristic is ‘A mental shortcut in which one judges an event to be an instance of a particular category when the event has some characteristics that are consistent with that category’ (Sc.Maricopa.edu, 2003). In a simpler form, we conclude that an event is an instance of a particular category because it seems to be representative of other instances of that category. This heuristic typically relies upon the use of stereotypes, to make decisions about which category an object, event or person belongs in. Judging by Resemblance- E.g. a situation in which you have just met your new next-door neighbour. While talking, you notice that she is dressed in a conservative manner, has neat personal habits, a very large library in her home and seems to be very gentle and shy. She doesn’t mention what she does for a living and you later wonder, is she a business manager, a physician, a dancer, a waitress or a librarian? A quick way of making a guess is to compare her with other members of each of these professions. Deciding how well she compares to people of these occupations, and what similarities they have. By proceeding in this manner, you can quickly conclude that she is probably a librarian; her traits are similar to those that a librarian would possess, rather than those of the dancer, business manager or the physician. By making this judgement about the neighbour’s occupation, the representative ness heuristic is being used. The more similar the individual is to typical members of a given group, the more likely the individual is to belong to that group.
The anchoring and adjustment heuristic uses a number as a starting point, and adjusts judgements away from the anchor. It involves “Starting from an initial value that is adjusted to yield the final answer. The initial value, or starting point, may be suggested by the formulation of the problem, or it may be the result of a partial computation. In either case, adjustments are typically insufficient” (Tversky and Kahneman, 1974, p.1128). An example of this heuristic could be planning a two week trip on holiday to Florida and you want to know the costs in advance. By starting from a low anchor (£300 for flight and tickets) and thinking about additional costs in an upward adjustment process. As an alternative, you start from the higher anchor of £2000, and subtract what expenditures could be saved. Since the memory search for costs to be added or saved is typically incomplete, the upward adjustment process usually results in a lower estimate then the downward adjustment process (Hewstone et al, 1996).
Inferences are judgements and opinions that we conclude from factual evidence or reasoning. To make a distinction between inferences and retrieval, it is often based on random choice, assuming that retrieved information is genuine (so identical with what has been learned before). Inferred information is the product of creative invention. Proponents of a constructivist memory view would not even maintain this assumption, because recalled information is no longer a copy of the original information. Bearing the strong resemblance between the two concepts in mind, the notion of social inferences is intended here to highlight the creative nature of social cognition (Hewstone et al, 1996). A lot of research on social inference is concerned with inferences from behaviour to dispositional traits. An n investigation by Reeder and Brewer (1979) explains the schema structures, which determine such inferences. In the input of ethics, inferences from negative behaviour (e.g. lying) to corresponding traits (dishonesty) are drawn more readily than are inferences from positive behaviour (telling the truth) to positive traits (honesty) (Hewstone et al, 1996). So more positive than negative behaviours are necessary to confirm a trait by repeated observation or induction. There are two steps in social inference, firstly gathering data –the process by which people select the information they will use to answer their questions. Step two is integrating the data-the process by which people interpret the data and draw conclusions about them. In the rules of right and wrong, the inference schema places stronger restrictions on positive than on negative traits: an honest person is expected to show positive or at least neutral behaviour, but hardly ever-negative behaviour. By contrast, a dishonest person is not expected to lie or cheat all the time; rather, the trait of dishonesty is compatible with a broader range of negative, neutral and positive behaviour. Negative information has more characteristics and receives more weight in social judgement than positive information (Skrowronski and Carlston, 1989). Negative behaviour clearly indicates negative traits whereas positive behaviour occurs with positive as well as negative traits.
Judgements that people make are not always accurate. Social inference is affected by heuristics that we use in everyday life.
By relying on the availability heuristic in making social judgements it can lead to errors. An important way in which availability can lead us in to error involves the fact that the occurrence of an event typically is more obvious to us (and so more memorable and available) than is its non-occurrence. For example, the common belief that washing ones car causes it to rain. Many people readily notice occasions on which it rains soon after they have washed their car. This makes it more likely that they will form memories of these occasions and that they will easily recall them in the future. On the other hand, most people probably don’t notice occasions on which it does not rain soon after they have washed their car; or occasions on which it rains when they have not washed their car. Such non-occurrences are not remembered. In general we have stronger and more enduring memories for occasions on which something happened, which causes us to overestimate their frequency. In such cases the availability heuristic can lead us in to errors, because our subjective feeling that something is easy to bring to mind is not a reliable guide to its importance or accuracy
(Baron and Byrne, 2000).
Judgements are made, such as how similar an individual is to typical members of a given group, and then the more likely he or she is to belong to that group. People put others into categories from their past experiences, and by belonging to these different groups it does affect the style and behaviour of the people in them. Certain groups attract people with certain traits in the first place. Often our own inferences based on representativeness are wrong, mainly for the reason that: decisions or judgements made on the basis of this rule tend to ignore base rates-the frequency with which given events or patterns, such as occupations occur in the total population (Tversky and Kahneman, 1973; Koehler, 1993). In the librarian example, most people would have thought that their neighbour was a librarian. Even though she seemed more similar to a librarian than a business manager in her personal traits, the chances are higher that she is in business than a librarian, as there are many more business managers than librarians-perhaps fifty times as many-in the population. In this and other related ways, the representativeness heuristic can lead to errors in our thinking of other persons.
Research suggests there is more to the availability heuristic than the way in which relevant information comes to mind. The amount of information that comes to mind is also important. The more information that we can think of, then the greater its impact on our judgements. Which of these two factors is most important depends on the kind of judgement we are making. If the judgement involves emotions or feelings, we tend to rely on the ‘ease’ rule; if it involves facts or information, the ‘amount’ rule comes in to play.
The availability heuristic seems to include two different rules for judging the importance of information: how easy it comes to mind and how much we can remember. Which of these rules that we follow depends strongly on the kind of judgement that we are making.
References
Website
Sc.Maricopa.edu, (2003). Critical thinking. Sc. Maricopa.edu [online], [cited 16/03/04]. Available from URL: http://www.sc.maricopa.edu/sbscience/ricker/intro/essays/essay8b.html
Books
Baron, R.A., Byrne, D. (2000). Social Psychology: Ninth Edition. Massachusetts: Allyn and Bacon.
Eysenck, M. (1998). Psychology: An Integrated Approach. Essex: Prentice Hall.
Hewstone, M., Stroebe, W. and Stephenson, G.M. (1996). Introduction to Social Psychology: Second Edition. Massachusetts: Blackwell Publishers.
Passer, M.W., Smith, R.E. (2001). Psychology: Frontiers and Applications. New York: McGraw-Hill.
