accuracy of eye witness testimony Flashcards
what is eye witness testimony?
evidence supplied by people who witness a specific event or crime, relying on their memory
what are the 2 factors that can affect eye witness testimony?
● misleading information
● anxiety
what is misleading information? (2)
● incorrect information given to eyewitness usually after event
● for example, leading questions and post event discussions
what is a leading question?
a question which, because of the way it’s phrased, suggests a certain answer
describe the key research of loftus and palmer (5)
● students shown video clips of road traffic accident
● then students were split into 5 different groups
● all participants were asked ‘how fast were the cars going when they smashed / contacted / other verbs into each other
● participants recalled that the mean estimate of speed was higher when verb smashed was used
● whereas, mean estimate of speed was lower when verb contacted was used
what did loftus and palmers research conclude about leading questions? (2)
● leading questions can clearly influence people’s perception of speed
● as those who heard more emotive verbs (smashed) will give higher speed estimates than less emotive verbs like (contacted)
why do leading questions affect EWT? (2)
● response bias
● substitution
what is the response bias explanation for leading questions affecting EWT? (2)
● wording of a question has no actual effect on a person’s memory
● but instead just influences how they decide to answer
what is the substitution explanation for leading questions affecting EWT?
wording of question actually does change a person’s memory of an event
describe loftus and palmer’s follow up study (5)
● students watched short video of car accident
● group 1 asked how fast cars going when they hit (low impact verb) each other
● group 2 asked how fast cars going when they smashed (high impact verb) into each other
● group 3 was not asked about speed of vehicle
● followed up a week later and asked - ‘did you see any broken glass?’ (there wasn’t any)
what were the findings of loftus and palmers follow up study? (2)
● critical verb in question altered memory of incident (substitution)
● participants genuinely believed that there was broken glass in the smashed condition
what is post-event discussion? (2)
● occurs when there is more than one witness to an event
● those who have observed event will discuss what has happened with other co-witnesses
why does post-event discussion affect EWT? (2)
● memory contamination
● memory conformity
what is memory contamination?
when co-witnesses discuss an event, they mix information they get from others with their own memories
what is memory conformity? (2)
● people simply go along with what each other are recalling simply for social approval
● or because they believe other person must have the right info
what is anxiety?
a state of emotional and physical arousal to a stressful situation
why does anxiety have a negative effect on recall? (2)
● creates physiological arousal in body
● which prevents us paying attention to important cues / details in environment
what is the supporting research that suggests anxiety has a negative effect on recall? (5)
● johnson and scott
● p’s thought - taking part in lab study - put in ‘waiting room’ - disagreement next door
● condition 1 (low anxiety group) - heard quiet disagreement - saw man leave room holding pen with grease on his hands
● condition 2 (high anxiety group) - heard heated argument - saw man leave room holding knife with blood on his hands
● had to later identify man from set of 50 photos
what were the findings and conclusion of johnson and scott’s research? (3)
● 49% in low anxiety group were accurate
● 33% in high anxiety group were accurate
● conclusion: supports ‘the weapon effect’ in that witnesses attention is drawn towards weapon as it is a source of danger and anxiety and therefore will not take in any other info of scene
why does anxiety have positive effect on recall? (2)
● stress of seeing crime / accident triggers fight-or-flight response which increases alertness
● so we become more aware of surroundings including cues/details of situation
what is the supporting research that anxiety has positive effect on recall? (4)
● yuille and cutshall
● studied real life robbery / shooting in gun shop where owner shot thief dead
● witnesses interviewed 5 months later and compared recall to original account given to police at time of incident
● also asked to rate stress levels at time of incident and if they had experienced any emotional problems since
what were the findings and conclusion of yuille and cutshall’s research? (3)
● witnesses were very accurate in their accounts with little changes in accuracy over 5 months (some minor details = less accurate)
● found that those who reported highest levels of stress were most accurate in recall = 88% in most stressed and 75% for less stressed
● conclusion: anxiety can have positive impact on recall of events
how can we explain the contradictory finding of anxiety both having a positive and negative effect on recall?
the inverted U
what does the inverted U suggest? (2)
● anxiety increases accuracy of EWT (due to increasing attention) up to optimal point
● after this, strong anxiety impairs accuracy of EWT
