Factors affecting the accuracy of eyewitness testimony Flashcards
misleading information, including leading questions and post-event discussion; anxiety.
what was Bartlett’s theory?
he argued that memories are not accurate ‘snapshots’ of events preserved but are instead ‘reconstructions’ of events influenced by our personal attitudes and stereotypes
why does bartlett’s theory raise a problem for the use of EWT?
because recall is not objective
what is a schema?
packages of information about people and objects in the world around use
mental shortcut - when we recall a memory it is influenced by schemas, memories change to fit with the individuals pre-existing bias
what is reconstructive memory?
memory is not an accurate recording of events
it is reconstructed in recalling and may produce errors (confabulations)
what are leading questions?
questions that imply a particular answer can influence how a memory is recalled
how can leading questions lead to misleading information?
there may be an actual change to the memory (substitution bias explanation) or there may be an emotional pressure to give a particular response (response bias explanation)
what is post-event discussion?
when the recalling of events by one witness alters the accuracy of the recall by another witness
this could be memory conformity (the witnesses go along with other witness accounts for social approval)
research evidence for EWT
procedure: Loftus and Palmer (1974) showed 45 PPs clips of traffic accidents and were asked the leading question: “How fast were the cars going when they ___ into each other?” - the verb was changed to smashed, collided, bumped, hit or contacted
findings: the more extreme the verb the faster the estimation of speed
contacted = 31.8 mph
smashed = 40.8 mph
conclusion: suggests leading questions can influence the recall of EWT
research evidence for EWT part 2
procedure: in a follow up study the participants were asked: “did you see broken glass?”
findings: PPs were twice as likely in smashed condition to respond ‘yes’ compared to the hit condition
conclusion: suggests the effects of leading questions can be long lasting and actually change memories via substitution rather than response bias
research evidence for post event discussion
Gabbert et al (2003)
procedure: videos of crimes shot from different perspectives shown to pairs of participants with unique information available in each film
findings: 71% of pairs allowed to discuss what they had seen included aspects of the film they had not seen in their recollection of the video
compared to 0% in pairs who were not allowed to discuss what they had seen
conclusion: suggests that witnesses will change their account of crimes to match others to seek social approval resulting in memory conformity
what is anxiety?
a mental state of arousal that includes feelings of extreme concern and tension accompanied by physiological changes e.g. increased heartbeat
how may anxiety affect EWT?
decrease recall or increase recall or a bit of both
how may anxiety decrease recall?
high levels of anxiety produce reduced recall of the criminals face
an explanation for this is weapon effect/focus - weapons are a cause of anxiety so witnesses focus their attention on the weapon rather than the criminal
how may anxiety increase recall?
high levels of anxiety may improve alertness and awareness of the situation and surroundings
strong emotions could improve memory encoding
explain the Yerks-Dodson Law of arousal
EWT accuracy increases as anxiety raises as the witness becomes alert
however at a point anxiety becomes too high and more stress and distraction results in lower accuracy
shown using a bell-shaped curve (anxiety against EWT accuracy)
research evidence for EWT - anxiety decreases EWT accuracy
Johnson and Scott (1976)
procedure: naive participants were placed outside a lab listening to conversations
condition 1: normal conversation about equipment failure, man walks out with greasy hands and a pen
condition 2: hostile, breaking glass, furniture knocked over, man walks out with knife covered in blood
PPs asked to identify the man from 50 photos
findings: more participants in condition 1 identified the man with the pen (49%) than condition 2 with the knife (33%)
conclusion: suggests knife causes anxiety resulting in decreased focus on mans face and more on the weapon - weapon focus
research evidence for EWT - anxiety increases EWT accuracy
Yuille and Cutshall (1986)
procedure: interviewed 13 witnesses to a real shooting 4 months after
findings: witnesses resisted misleading information and those with the most stress produced the most accurate EWT
conclusion: suggests misleading information and anxiety may not be a significant problem for real world EWT
evaluations for EWT factors
+ real-life application in the development of the cognitive interview - to reduce the influence of schemas on the accuracy of recall
+ lab experiment - control over extraneous variables - high internal validity
- lab experiment - demand characteristics (Please-U effect) - want to help the researcher by giving them the response they expect - response bias explanation
+ lab experiment may mean there is a lack of consequences for providing inaccurate EWT so in a real life case under oath people are more likely to provide more accurate EWT
- unethical - failed to protect PPs from harm as they had to experience trauma that caused anxiety in some experiments
