factors affecting EWT+ improving accuracy✅ Flashcards
what is an eyewitness testimony?
evidence given to police/court by someone who has witnessed a crime
what are the factors that affect eyewitness testimony?
- misleading information
- leading questions or post event discussion
- anxiety
what was the aim of Loftus and Palmer’s first study?
to investigate how misleading info (particularly leading questions) can influence EWs memories of an event
what was the procedure of Loftus and Palmer’s first study?
- 45 Ps were shown 7 clips of cars colliding
- split into 5 groups with 9 in each
- participants were asked “how fast were the cars going when they ____ into each other”
- each group was given a different verb ; smashed, collided, bumped hit or contacted
what were the findings of Loftus and Palmer’s first study?
- smashed = 40.8 mph
contacted = 31.8 mph - how question was phrased influenced participants speed estimates
what was the aim of Loftus and Palmer’s second study?
to see if people would remember details that arent true
what was the procedure of Loftus and Palmer’s second study?
- Ps were shown short video of multi-vehicle accident and were then asked questions
-participants were split into 3 groups- 50 in each - G1-“how fast were they going when they hit each other”
- G2- “how fast were they going when they smashed into each other?
- G3 were not asked about the vehicles
-one week later participants were asked if they saw any broken glass
–> there was NO BROKEN GLASS in vid
describe the results of Loftus and Palmer’s second study
- smashed group= 30% said glass
- hit group- 14% said glass
- control group- 12% said glass
what are the two explanations for why leading questions affect EWT?
- response-bias explanation
- the substitution explanation
describe the response-bias explanation
- suggests wording of question has no real effect on P’s memories
- just influences how they choose to answer
describe the substitution explanation
- wording of question actually changes the Ps memory
eg: Ps who heard word smashed more likely to report seeing broken glass
what is the procedure of Gabbert(2003)’s study regarding post event discussion?
- sample included 60 students and 60 older members of community
- participants watched video of girl stealing money from wallet by themselves
- they were then tested either individually or in pairs (co-witness)
- co-witnesses were told they had seen same vid, however only one had actually seen girl stealing
- cowitness participants discussed the crime together, then completed questionnaire
what were the findings of Gabbert’s study of post event discussion?
- 71% of witnesses in co-witness group recalled info they had not actually seen
- 60% said the girl was guilty, despite the fact they had not seen her commit the crime
- these results highlight the issue of post event discussion regarding EWTs
what are the two explanations of the effects of post event discussion
- source monitoring theory
- conformity theory
describe source monitoring theory
- memories are genuinly distorted
- eyewitnesses can recall information from the event (accurate or inaccurate), but cannot recall where it came from
-was it from their memory or from someone else’s? –> This is known as source confusion
describe conformity theory regarding post event discussion
- eyewitness memories are not actually distorted by PED
- recall changes as they go along with the accounts of co-witness
- this could be to win social approval or because they genuinely believe other witnesses are right and they are wrong
what are some A03 points of misleading information?
- research into misleading questions isnt generalisable –> loftus and palmer used students
- research was conducted in lab–> high reliability increases validity
- evidence is useful–> train police to not influence EWS–> applicable to real life
describe the method of Johnson and Scott’s study regarding anxiety
- participants believed they were taking part in lab experiment–>while in waiting room, they heard argument in next door room
- ‘low anxiety condition’ - discussion was heard, then man left with pen and grease on his hands
- ‘high anxiety condition’- heated discussion was heard, followed by man leaving with pen knife covered in blood
- Ps asked to identify man from 50 photos
what were the results from Johnson and Scott’s study regarding anxiety?
- low anxiety condition= 49% accurate
- high anxiety condition= 33% accurate
- anxiety has negative effect on eye witness testimony
- this phenomenon is called weapon focus (loftus et al)
describe weapon focus by Loftus et al.
- during violent crimes, arousal focuses witness on central details (weapon) rather than peripheral details
- this leads to poor recall of crime details
describe Yuille and Cutshall’s study regarding anxiety on EWTs
- conducted study of real life shooting in gun shop in Canada
- interviews with witnesses took place 4-5 months after event
- these interviews were compared to original police interviews
- Ps asked how stressed they felt on a 7 point scale + whether they had emotional problems since
eg: sleeplessness
what were the results of Yuille and Cutshall’s study?
- witnesses were very accurate
- participants who had reported highest levels of stress were most accurate (88%)
- less stressed were less accurate (75%)
- anxiety improves EWTs
what does Deffenbacher say about anxiety and recall accuracy?
- low levels of anxiety produce low levels of recall accuracy, but memory becomes more accurate as anxiety increases
- however, at a certain point optimal anxiety is reached–> this is point of maximum accuracy
- if stress goes beyond this, recall then suffers a drastic decline
what are some A03 points of anxiety as a factor affecting eyewitness testimony
-evidence suggesting weapon focus isn’t relevant–> lacks internal validity
-ethical guidelines were broken during Johnson and Scott’s research
-strenth= research by Christianson and Hubinette was in context of real crime
