Eyewitness Testimony
Reconstructive Memory
If you tried to, right now, draw a picture of a €1 or £1 coin or a $1 note then you probably would not be able to, even though you use it everyday. You would be able to remeber certain features, but it would not be fully accurate and complete. This is an example of reconstructive memory.
This observation of memory by Bartlett says that reconstructive memory is putting the pieces of information from a memory together, but often in the wrong order, with bits missing or added.
Reconstructive memory is a particular problem when it comes to the law. In criminal cases a witness often provides critical information against the defendant. However, it is possible that the eyewitness tesimony is inaccurate becuase the memory was not reconstructed correctly
What Affects Eyewitness Testimony Accuracy?
There are many different factors which may affect how good the account of someone who saw a crime is. These factors are very important in courts because they could determine the innocence of someone.
The first and propably most obvious factor is age in general it is considered that younger children and the quite elderly are not very reliable. However, decline in memory with age is not so obvious and in many people their memory remains the same; especially if they continue to use the mind (i.e. someone with alot of education or who had a mentally challenging job).
Have a look at the two studies below for research evidence to this.
| Karpel et al (2001) EWT in elderly | Martin et al (1979) EWT in Children | |
|---|---|---|
| Aim | To see how reliable eye witness testimony (EWT) is in older people. | Test age differences between children and young adults. |
| Method | Young adults (17 - 25) and older adults (65 - 85) were shown a video of a robbery. They were then asked to recall what they'd seen. This information was then compared. | Primary school, junior school, senior school and college aged students saw a 15 second scene of a distressed man. They were tested on information straight after and 2 weeks later. |
| Results | The information given by the young adults was more accurate and they were less vulnerable to leading questions. | Recall of both correct and incorrect information increased with age and importantly, there was no significant difference in accuracy and influence of leading questions. |
| Conclusions | Young adults make more reliable eyewitnesses. | Although younger children recall less information, the key information is unaffected. |
| Evaluation | Poor ecological validity because a video was used. Demand characteristics where the participants guess the aim of the experiment and therefore make a special effort to remember what happened. |
General evaluation about using children includes: Studies usually use emotionally positive events but a real EWT is unlikely to be. Children are not put under pressure whereas in real-life they propably would be. |
A second factor which will affect the accuracy of eyewitness testimony is the use of leading questions. A leading question is where you ask something, but include information that could cause you to give a different answer. For example: "Wasn't the driver wearing a red shirt?" After being given this question a witness may describe the driver as wearing a red shirt where they wouldn't have previously.
| Aim | Loftus and Palmer (1974) wanted to see if the wording of a question affects recall. |
|---|---|
| Method | A sample of students were shown a clip of a traffic accident. They were then asked about the speed of the car when it: bumped, collided, contacted, hit or smashed. |
| Results | The average speed when a particular word was used is shown below (in miles per hour). Contacted 31.8 Hit 34.0 Bumped 38.1 Collided 39.3 Smashed 40.8 |
| Conclusion | The wording of questions can affect the judgements of an eyewitness, and may prompt false memories. |
| Evaluation | May not have very good ecological validity because students were used, and therefore the findings cannot be generalised to the whole population, also it is only relevant to the English language, and even in different cultures where English is spoken it is used may produce different results. There are demand charcteristics, where the participants gave higher speeds because they thought this is what the experimenter wanted rather than as a result of a leading question. |