Tversky and Kahneman- Availability heuristic

What was the aim?

The aim was to investigate the effect of the availability heuristic on the frequency of appearance of letter 'K' in words

who was the sample group?

152 participants recruited from a student newspaper in USA Oregon.

Conclusion

Despite the fact that in general the availability heuristic guides us in the right direction, as things that come to mind easily are more likely to be common, it may also mislead greatly. It was indicated that the use of system 1 thinking, a mode of thinking that is fast and intuitive was used, resulting in inaccuracies. Tversky and Kahneman argue that the number of examples recalled from memory is used to infer the frequency with which such instances occur. Thus, people judge words beginning with a "K" to be a more common occurrence.

Background

In 1973, Amos Tversky and Daniel Kahneman first studied this phenomenon and labeled it the "availability heuristic".

Procedure

They gathered a sample of university students, and asked the participants "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?" more concentrated effort to think of words with letter in third position rather than first.

Define the availability heuristic and give an example

the availability heuristic is a mental shortcut, that estimates the likelihood or frequency of events based on their availability in memory; if instances come to mind readily we presume such events are common. According to this heuristic, we are more inclined to retrieve information that is easily recalled or recently encountered. An example of irrational decision making. This could perhaps be explained by the availability heuristic: people who win the lottery are given a lot of media attention and coverage, therefore it may be easy to recall an instance of a lottery winner to mind. In contrast, people dying from smoking will be far less prominent. As a result, we overestimate the chances of a lottery win and underestimate the possibility of the smoking-related disease.

What was the DV?

the mean estimate of words beginning with K compared to the estimate of words as k in the third position

Define cognitive biases

A cognitive bias is a systematic error in thinking that occurs when people are processing information that consequently affect the decisions and judgments they make. They lead to unreliable decision making processes.

What was the IV?

the IV

Strengths of the study

. clearly demonstrates the use of system 1 thinking, as Ps have to make a quick decision and so rely to system 1 and availability heuristic. . high internal validity .easy to predicate hence high repeatability .high construct validity

Limitations of the study

. the task is quite superficial and unrealistic, as it does not concern a situation where important consequences would follow the decisions made so Ps are unlikely to invest more effort in coming to a more rational choice, due to lack of motivation and interest.so low mundane realism . lack of ecological validity. In real life there are more complex factors affecting our decisions than just the factors presented by the researchers under laboratory conditions. . lack of cross cultural support, . - assuming that cognitive biases are universal . low population validity as it was just western white university students. lack of external validity as results are not generalisable to people beyond the sample in the study.

crtitical thinking of cognitive bias

1. It is difficult to measure the actual use of such biases in real life situations. In real life there are more complex factors affecting our decisions than just the factors presented by the researchers under laboratory conditions. Also in real life there are more important consequences related to the decisions we make, hence we might turn to system 2 thinking. 2. Much of the research in this topic is done with Western university student samples under highly controlled - and rather artificial - conditions. Many of the questions given to the students would be of little interest to them and were not asked in a way that was natural. The studies lack ecological validity as well as cross-cultural support - assuming that cognitive biases are universal

does knowing about biases help in real life?

Knowing about biases doesn't help us! Kahneman himself describes how he still falls prey to the biases he described. In other words knowing about them does not seem to affect our initial decision making a process! It is therefore not clear from this research how we are to go about making ourselves more rational (or even if it would be a good idea to do so).

results of the study

Results indicated that participants overestimated the number of words starting with K and underestimated the number of words that had "K" as the third letter. This is because it is easier to think of examples of words that begin with the letter K, more so than words with 'K' as the third letter. However, this is largely inaccurate because there are actually 3x more words in the english dictionary that have K as the third letter compared to words that start with K. -105/152 participants judged the first position to be likely for a majority of letters

Applications of the results

in real life conditions, the availability heuristic often leads to misdiagnosis, due to the need to reach quick conclusions. a study by Weinstein et al showed the tendency of doctors to overestimate the risk of addiction when prescribing opioids for pain relief and to undertreat severe pain as a result. They should ask if their decision is influenced by any salient pieces of information and, if so, whether these pieces of information are truly representative or simply reflect recent or otherwise particularly memorable experiences. Knowing whether information is truly relevant, rather than simply easily available, is the key.