EWT Flashcards
What is an EWT?
The ability of people to remember the details of events, such as accidents and crimes, which they themselves have observed.
What factors can affect an EWT?
Factors such as misleading information, leading questions and anxiety.
What is EWT used for?
- Recorded in a police statement
- Verbal testimony to be used as evidence in a court of law
What is misleading information?
Incorrect information given to the eyewitness usually after the event.
What forms can misleading information take?
Leading questions and post-event discussion between co-witnesses and/or other people.
What is a leading question? What is an example?
A question which, because of the way it is phrased, suggests a certain answer. E.g. “Was the knife in the accused’s left hand?”. This suggests the answer is ‘left hand’.
Who investigated the effect of leading questions on eyewitness testimony?
Loftus and Palmer
What was Loftus and Palmer’s procedure?
A laboratory experiment. Three groups of students, after watching a film of a car crash were asked questions (an independent measures design): -
The first group were asked – “How fast were the cars going when they hit each other?”
For the other group the words: - smashed into each other were substituted.
A control group were not asked about speed.
A week later they were re-interviewed and asked: - “Did you see any broken glass?”
What were the results of Loftus and Palmer’s study?
The smashed group’s average estimated speed was 41mph
The hit group’s average estimated speed was 38mph
Although there was no broken glass at the scene 32% of the participants who heard the word smashed said there was, compared to only 14% of the hit group and only 12% of the control group.
What was there conclusion?
The participants had unconsciously incorporated connotations (of speed and force) into their memory of the event and it had affected their judgement of speed and memory of the scene.
What are the two explanations for why leading questions affect EWT?
Response bias and Substitution
What is the response bias explanation? E.g
The wording of the question doesn’t affect participants’ memories, it just influences how they decide to answer.
E.g. When a participant is asked a leading question using the word smashed – this encourages them to estimate a higher speed
What is the substitution explanation? E.g
The wording of the question actually changes the memory of the film clip
E.g. Participants who originally heard ‘smashed’, were more likely to report broken glass when asked later
What is post-event discussion?
Occurs when there is more than one witness to an event. Witnesses may discuss what they have seen with their co-witnesses or with other people. This may influence the accuracy of each witness’s recall of the event.
What can happen when co-witnesses discuss?
When co-witnesses discuss the observed crime with each other, their EWT may become contaminated. This is because they combine (mis)information from other witnesses with their own memories
Who investigated the effects of post-event discussion on the accuracy of EWT?
Gabbert
What was Gabbert’s procedure?
Participants were studied in pairs
Each participant watched a video of the same crime, but filmed from different points of view (positions)
Each participant could see elements of the events that the other could not (e.g. only one of the participants could see the title of the book carried by a young woman)
Both participants then discussed what they’d seen before taking a recall test on their own
What were the results of Gabbert’s study?
71% of the participants mistakenly recalled aspects of the event they did not see but had picked up from discussion with their partner
In the control group, where there was no discussion, there was no information incorrectly recalled (0%)
What was the conclusion of Gabbert’s study?
Witnesses often go along with each other
To gain social approval or because they believe the other witnesses are right and they are wrong
Gabbert (2003) called this memory conformity
What is anxiety? What does it include?
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 sweatiness. Anxiety is a normal reaction to stressful situations, but can affect the accuracy and detail of eyewitness testimony.
What is the negative effect of anxiety on EWT?
Anxiety causes physical arousal in the body which prevents us from paying attention to vital cues – recall is worse.
What is weapon focus effect?
The effect of weapons (which cause anxiety) on the accuracy of witness recall
Who investigated the effect of weapons on the accuracy of EWT?
Johnson and Scott
What was Johnson and Scott’s procedure?
Participants were told they would be taking part in a lab study
Whilst sitting in a waiting room participants heard an argument in the room next door
Low anxiety condition – a man walked through the waiting room carrying a pen with grease on his hands
High anxiety condition – a man walked through the waiting room carrying a paper knife that was covered in blood
