Eye-witness testimony Flashcards
What is an eye-witness?
Someone who has seen or witnessed a crime, usually present at the time of the incident. They use their memory of the crime to give their testimony or a ‘reconstruction’ of what happened.
Who researched EWT?
Loftus and Palmer (1974)
Describe Loftus and Palmers procedure in their experiment on EWT
45 student participants watched film clips of car accidents and were then asked leading questions about speed. In the critical question (leading question or misleading information) the participants were asked to describe how fast the cars were going. There were 5 different groups of participants. Each group was given a different verb in the critical question, varying in severity: ‘contacted’, ‘hit’, ‘bumped’, ‘collided’ and ‘smashed’
How many participants were in the Loftus and Palmer ‘car crash’ study?
45 student participants
What were the 5 verbs used in Loftus and Palmer’s ‘car crash’ study?
Contacted
Hit
Bumped
Collided
Smashed
What were Loftus and Palmers findings in the ‘car crash’ study?
The mean estimated speed was calculated for all 5 groups
The verb ‘contacted’ (the least severe) gave a mean speed of 31.8mph. The verb ‘smashed’ (the most severe) gave a mean speed of 40.5mph. This showed that the leading question, in this case the severity of the verb used, biased the eyewitness’s recall of an event
What was the mean speed when the least severe verb (‘contacted’) was used?
31.8mph
What was the mean speed when the most severe verb (‘smashed’) was used?
40.5mph
Why do leading questions affect EWT?
The response-bias explanation suggests that the wording of the question has no real effect on the participants’ memories, but just influences how they describe the answer
Loftus and Palmer (1974) conducted a second experiment that supported what explanation?
The substitution explanation, which states that the wording of a leading question changes the participants memory of a film clip
What was Loftus and Palmers’ second experiment?
The broken glass experiment
Describe the procedure of the broken glass experiment
150 student participants were shown a film of a multi-vehicle car accident and asked questions about it
The participants were split into 3 equal groups:
1st group: ‘How fast were the cars going when they hit eachother?’
2nd group: ‘How fast were the cars going when they smashed into each other?’
3rd group: asked nothing about the speed. All groups returned a week later and were asked, “did you see any broken glass?”, even though there was none in the film.
How many participants were there in the broken glass experiment?
150 student participants
Describe the 3 groups that the participants were split into in the broken glass experiment
1st group were asked ‘How fast were the cars going when they hit eachother?’
2nd group were asked ‘How fast were the cars going when they smashed into each other?’
3rd group were asked nothing about the speed
What were the results of the broken glass experiment when the participants were asked “did you see any broken glass?”
The 1st group that was given the verb ‘hit’: 7 said yes, and 43 said no
The 2nd group that was given the verb ‘smashed’: 16 said yes, and 34 said no
The 3rd group that were asked nothing about the speed: 6 said yes, 44 said no
Who carried out research on post-event discussion (PED)
Gabbert (2003)
What is meant by PED?
Eyewitnesses to a crime may sometimes discuss their experience and memories with each other.
Describe Gabbert’s procedure in his PED experiment
Studied participants in pairs. Each participant watched a video of the same crime but filmed from 2 different points of view. Each participant could see something the other one could not. Both participants then discussed what they had seen before individually completing a test of recall.
What were Gabberts findings in his PED experiment?
71% of participants mistakenly recalled aspects of the event that they did not see in the video but had picked up in the post-event discussion. They also completed the study with a control group where NO discussion occured. In this experiment there was 0% mistakes. This was evidence of memory conformity
What are the 2 explanations that explain why PED affects EWT?
Memory contamination and memory conformity
Describe memory contamination
When co-witnesses to a crime discuss it with others, their testimonies become altered or distorted. This is because they combine (mis) information from other witnesses with their own memories.
Describe memory conformity
Gabbert concluded that witnesses often go along with each other, either to win social approval or because they believe the other witnesses are right and they are wrong. Unlike with memory contamination, the actual memory is unchanged.
Give a strength of misleading information as a factor affecting the accuracy of EWT
Strength - real world application. Important practical uses in the criminal justice system - the consequence of innacurate EWT can be very serious. Loftus (1975) believes that leading questions can have such a distorting effect on memory that police officers need to be extremely careful about how they phrase their questions when interviewing eyewitnesses. Psychologists are sometimes asked to act as expert witnesses in court trials and explain the limits on EWT to the juries
Give 2 limitations of misleading information as a factor affecting the accuracy of EWT
- Artificial material - Loftus and Palmers research was carried out in a lab - the participants watched the crashes on a screen. This is a very different experience to real life and a lot less stressful. Psychologists (1986) found that witness of a traumatic robbery had very accurate recall after 4 months. This shows that using artificial tasks tells us little about how leading questions affect EWT in real crimes/ accidents
- Lack of external validity and demand characteristics - A psychologist (1994) argued that what you can remember as an eyewitness in real life can have important consequences - this is not true in a lab setting. Research participants want to be helpful so may answer a question even if they are unsure of the answer - demand characteristics. Therefore, EWT may be more accurate in the real world. Both of these challenge the validity of EWT research
