3.2 A psychological perspective
Man is not a rational animal; he is a rationalising animal.
None of us has infinite resources or time to devote to gathering and analysing information in order to support our decisions. In addition, there are limitations to the amount of complexity we can cope with.
So even where we make conscious efforts to make decisions according to a more rational process, we often need to make simplifying assumptions and accept that we may not have all the information that we would like.
In order to do this, and to help make decision making easier, we each work with a set of often unconscious ‘rules of thumb’ to guide us: for example, rather than engaging in a detailed evaluation of the merits of different breakfast cereals on a daily or weekly basis, we might save time and energy by associating a particular brand with quality and choose that by default.
Many of these rules of thumb are entirely unconscious and while often useful, may also lead to some significant biases in our decision making. There are six commonly held sources of bias which can hamper our decision making:
- Confirmation bias – the tendency to search for and interpret information consistent with our existing beliefs
- Availability bias – the tendency to overestimate the importance of something we can remember easily
- Hindsight bias – the tendency to see past events as being more predictable than they were before the event occurredAnchoring effect –the tendency to overemphasise or over-rely on a single piece of evidence
- Framing effect –the tendency to draw different conclusions from the same information presented in different ways, e.g. a food is ‘85% fat free’ or ‘contains 15% fat’
- Meta-cognitive bias –the tendency to believe that while others may suffer from bias, we are immune from it
The effect of question framing on recall
Framing effects can be quite subtle and even affect our recall of events. For example, in one study, groups of students were shown a film of a car accident. Each group of students was shown the same film clip and then asked ‘How fast were the cars going when they xxxx each other?’ ‘xxxx’ was different for each group, variously ‘smashed into’, ‘collided into’, ‘bumped into’, ‘hit’ and ‘contacted’. The table below shows the average speed estimated by each group.
|Mean Estimate of Speed (mph)
Those who were asked the ‘smashed’ question were also more likely to believe they had seen broken glass in the film clip than those who were asked the ‘hit’ question. There was no broken glass.