Availability Heuristic - Research

Research

In a study by Schwarz et al., participants were asked to describe either 6 or 12 examples of assertive, or unassertive behavior. Participants were later asked to rate their own assertiveness. The results indicated that participants rated themselves as more assertive after describing 6, rather than 12, examples for the assertive behavior condition, and conversely rated themselves as less assertive after describing 6, rather than 12, examples for the unassertive behavior condition. The study reflected that the recalled content was qualified by the ease with which the content could be brought to mind (it was easier to recall 6 examples than 12).

In another study, subjects were asked, “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?” Most English-speaking people could immediately think of many words that begin with the letter "K" (kangaroo, kitchen, kale), but it would take a more concentrated effort to think of any words where "K" is the third letter (acknowledge). Results indicated that participants overestimated the number of words that began with the letter “K”, but underestimated the number of words that had “K” as the third letter. Researchers concluded that people answer questions like these by comparing the availability of the two categories and assessing how easily they can recall these instances. In other words, it is easier to think of words that begin with "K", than words with "K" as the third letter. Thus, people judge words beginning with a "K" to be a more common occurrence. In reality, however, a typical text contains twice as many words that have "K" as the third letter than "K" as the first letter. Additionally, there are three times as many words that have the letter "K" in the third position, as have it in the first position.

Chapman (1967) described a bias in the judgment of the frequency with which two events co-occur. This demonstration showed that the co-occurrence of paired stimuli resulted in participants overestimating the frequency of the pairings. To test this idea, participants were given information about several hypothetical mental patients. The data for each patient consisted of a clinical diagnosis and a drawing made by the patient. Later, participants estimated the frequency with which each diagnosis had been accompanied by various features of the drawing. The subjects vastly overestimated the frequency of this co-occurrence (such as suspiciousness and peculiar eyes). This effect was labeled the illusory correlation. Tversky and Kahneman suggested that availability provides a natural account for the illusory-correlation effect. The strength of the association between two events could provide the basis for the judgment of how frequently the two events co-occur. When the association is strong, it becomes more likely to conclude that the events have been paired frequently. Strong associations will be thought of as having occurred together frequently.

Research in 1992 used mood manipulation to influence the availability heuristic by placing participants into a sad mood condition or a happy mood condition. People in the sad mood condition recalled better than those in the happy mood condition, revealing that the power of the availability heuristic changes in certain conditions.