Factors affecting EWT Flashcards
What is an EWT?
When someone who has seen a crime gives their account on what they saw/believe that happened
What is misleading information?
Incorrect information given to participants after the event has occurred, sometimes to elicit a particular response
What is a leading question?
A question asked that brings a participant to a particular answer because of the phrasing
What is post-event discussion?
When participants talk about what they saw after the event with other participants or other people. This may influence their accuracy of the recall. As other people’s memories combine with their own.
Loftus and Palmer (1974) procedure and findings
They arranged for participants (students) to watch film clips of car accidents and then gave them questions about the accident. In the critical question (leading question), participants were asked to describe ‘how fast the cars were going when they hit each other?’ This is a leading question because the verb ‘hit’ suggests the speed the car was growing. There were 5 groups of participants (independent groups) [. Each was given a different verb in the critical question. These were ‘hit’, ‘collided’, ‘contacted’, ‘bumped’ and ‘smashed.’
The mean estimated speed was calculated for each group. The mean estimated speed for contacted was 31.8mph and for smashed was 40.5mph. The leading question biased the eyewitnesses’ recall of the event.
Loftus and Palmer response bias explanation
What occurred was not because the wording changed their memory; it just influenced how they chose to answer. E.g. smashed made them think faster, so they estimated higher.
Loftus and Palmer substitution explanation
The wording actually changes the participant’s memory of the film clip. This is supported by the finding that those who heard ‘smashed’ were far more likely to report seeing broken glass (when there wasn’t any) than those who heard hit.
Gabbert et al. (2003) procedure and findings
They studied participants in pairs. Each participant watched a video of the same crime, but the crime was filmed from different points of view. This meant that each participant could see elements of the event that the other could not. For example, only one of the participants could see the title of a book being carried by a young woman. Both participants then discussed what they had seen before individually completing a test of recall.
The researchers found that 71% of the participants mistakenly recalled aspects of the event that they did not see in the video but had picked up in the discussion. The corresponding figure in the control group, where there was no discussion, was 0%. Gabbert et al. 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. This is called memory conformity.
Supporting evidence - Loftus and Palmer
These studies support the validity of the explanation because they suggest that misleading information does affect the accuracy of EWT - substitute + response bias explanation
Supporting evidence Gabbert et al.
These studies support the validity of the explanation because they suggest that misleading information does affect the accuracy of EWT - memory conformity
Weakness of the L and P and G et al (anxiety) and what it shows
Loftus and Palmer’s study involved watching film clips of accidents. This is a very different experience from witnessing a real accident, mainly because such clips lack the stress of a real accident. There is some evidence that emotions can influence on memory - Johnson and Scott, 33% could recognise bloodstained knife, 49% recognised pen man
This suggests that studies that use such artificial tasks may tell us very little about how leading questions/post-event discussion affect EWT in cases of real accidents or crimes. It could even be that researchers are too pessimistic about the accuracy of EWT and it may be more reliable than the studies suggest.
Undermining research - consequences to EWT and what it shows
There are much greater consequences of being an eyewitness in real life than in a lab (person could go to prison). Research has found that if participants thought they were watching a real-life robbery and that their responses would influence the trial, their identification of the robber was much more accurate.
This suggests that studies that use artificial tasks may tell us very little about how leading questions/post-event discussion affect EWT in cases of real accidents or crimes. It could even be that researchers are too pessimistic about the accuracy of EWT and it may be more reliable than the studies suggest.
Strength of Loftus and Palmer and Gabbert et al. and what it shows
Strength - can control extraneous/confounding variables because in lab environment e.g. Loftus and Palmer can control post-event discussion and Gabbert et al. can control leading questions. Therefore they can be more confident in seeing cause and effect between leading questions (Loftus and Palmer)/post-event discussion (Gabbert et al.) and accuracy of EWT. Therefore the studies are internally valid support for the effect of misleading information on accuracy of EWT.
What is anxiety?
- Anxiety is a state of emotional and physical arousal. The emotions include having worried thoughts and feelings of tension. Physical changes include an increased heart rate and sweating.
How does anxiety affect recall
- Some think anxiety has a negative effect on recall – it creates physiological arousal in the body which prevents us paying attention to important cues, so recall is worse.
- Some think anxiety has a positive effect on recall – the physiological arousal from anxiety triggers the fight or flight response which increases our alertness and improves our memory for the event because we become more aware of cues in the situation.
What are the explanations for a negative effect on recall
Tunnel theory argues that a witness’ attention narrows to focus on a weapon because it is the source of the anxiety.
This leads to the weapon-focus effect where this tunnel focus then negatively affects the recall of the overall event.
Describe the Yerkes-Dodson Law
Negative quadratic
x-axis = low -> high anxiety
y-axis = poor -> very good EW recall
Johnson and Scott (1976) procedure and findings
Participants in this study were left in a waiting area outside a laboratory whilst waiting for the “real” study to start. While they were waiting one of two situations occurred. In the first situation (low anxiety), they overheard a discussion in the laboratory about equipment failure, followed by a man leaving the laboratory holding a pen and with grease on his hands. In the second situation (high anxiety), participants overheard a heated discussion in the laboratory with the sound of breaking glass and crashing chairs, followed by a man leaving the laboratory carrying a paper knife covered in blood.
The participants were later asked to identify the man from a set of 50 photographs with the result that 49% correctly identified the man holding the pen, but only 33% could identify the man with the bloodstained knife.
Yuille and Cutshall (1986) procedure and findings
They conducted a study of a real-life shooting in a gun shop in Vancouver, Canada. The shop owner shot a thief dead. There were 21 witnesses – 13 agreed to take part in the study. The interviews were held 4-5 months after the incident and these were compared with the original police interviews made at the time of the shooting. Accuracy was determined by the number of details recorded in each account. The witnesses were also asked to rate how stressed they had felt at the time of the incident on a 7-point-scale, and asked if they had any emotional problems since the event e.g. sleeplessness.
They found that the witnesses were very accurate in their accounts and there was little change in the amount or accuracy after 5 months, though some details were less accurate e.g. colour of items, age/height/weight estimates. Those participants who reported the highest levels of stress were the most accurate (88% compared to 75% for the less-stressed group).
Undermining research - testing surprise (Pickel)
It has been suggested that the Johnson and Scott (1976) study is actually testing surprise rather than anxiety. The reason why participants may focus on the weapon may be because they are surprised at what they see rather than because they are scared (anxious). Pickel (1998) conducted an experiment using scissors, a handgun, a wallet or raw chicken as the handheld items in a hairdressing salon video. They found that eyewitness accuracy was poorer in the high unusualness conditions – the raw chicken and the handgun.
This suggests that there may be an alternative explanation for the weapon-focus effect. This finding suggests that it may be unusualness, rather than threat, that captures our attention, and therefore affects memory for the rest of the event. Therefore, the study may not actually tell us anything about the effects of anxiety on EWT at all and so can’t be taken as strong support for the theory.
Weakness of Johnson and Scott study - risk and what it shows
Creating anxiety in participants can be very risky. It is potentially unethical because of the psychological harm they subjected to purely for research purposes. This is why real-life studies are so beneficial - psychologists interview people who have already witnessed a real-life event, so there is no need to create it.
This issue does not challenge the findings from research such as Johnson and Scott, but questions the need for such research. One reason is to compare the findings with less controlled field studies in order to determine cause and effect– and the benefits of this research may outweigh the issues as the anxiety is only short-lived. Therefore, it may be possible to justify such research to study the effects of anxiety on EWT.
