eyewitnesses Flashcards
eyewitness
someone who has seen or witnessed a crime. they use their memory of the crime to give their testimony of what happened
eyewitness testimony
- the ability of the person who saw the crime to remember the detail of the events they have observed
- their accuracy can be affected by factors such as misleading information and anxiety
misleading information
incorrect info given to an eyewitness after the event which affects the accuracy of their testimony
e.g. post-event discussion, leading questions
leading question
a question which because of its phrasing suggests a certain answer. this can affect accuracy of EWT
post-event discussion
- when there is more than 1 witness to the event, they may discuss what they have seen with each other
- this may influence the accuracy of their recall of the event
- because the witness combines information from other witnesses with their own memories
Loftus and Palmer (supporting evidence for misleading info affecting EWT)
- participants watched car accidents and were asked questions
- ‘how fast were the cars going when they hit each other’
- hit was replaced with collided, contacted, bumped and smashed in 5 different conditions
- mean speed for contacted was 31.8 while smashed was 40.5
- the leading question biased the eyewitnesses’ recall of the event
response bias explanation
leading question biased the eyewitnesses’ recall of the event
- because it influenced how they chose their answer- not because it changed their memory
- e.g. smashed makes them think faster, so they estimate higher
substitution explanation
leading question biased the eyewitnesses’ recall of the event
- because the wording changed the participants’ memory
e.g. those who heard ‘smashed’ were more likely to report seeing smashed glass than those who heard ‘hit’
Gabbert et al. study (supporting evidence for misleading info affecting EWT)
- pairs of participants watched a video of the same car crash but from different angles
- so each participant could see elements that the other could not
- the participants were then allowed to have post-event discussion
- 71% of participants recalled aspects of the event that they didnt see but had picked up in the discussion
(memory conformity)
real world application of misleading information affecting EWT - leading questions
- police are trained to not ask leading questions
- so memory is not distorted
- avoids serious consequences of inaccurate EWT
- supports external validity
weakness of misleading info affecting EWT - Loftus and Palmer (no stress)
- watching clips of accidents
- clips lack stress of a real crime
- artificial stimuli so cant be generalisable
weakness of misleading info affecting EWT - age
- older people are less accurate on EWT than younger people
- all age groups were more accurate at identifying people their own age
- so some age groups are less accurate
- so low internal validity
weakness of misleading information affecting EWT - demand characteristics
- participants dont want to let the researcher down
- so they are more inclined to guess than they would in a real life situation
undermining research of misleading info affecting EWT - consequences
- much greater consequences of being an eyewitness in real life than in lab
- if participants thought they were witnessing a real life crime, their recall was more accurate
- artificial stimuli means study isnt generalisable
strength of misleading information affecting EWT - controlled lab experiments
- can control EVs/CVs
- e.g. Loftus and Palmer control post-event discussion and Gabbert et al. control leading questions
- so internally valid
anxiety
a state of emotional and physical arousal (physiological)
how does anxiety have a negative effect on recall
- creates physiological arousal in the body which prevents us paying attention to important cues so recall is worse
how does anxiety have a positive effect on recall
the physiological arousal from anxiety triggers fight or flight response which increases alertness and improves our memory for the event because we are more aware of cues in the situation
what is tunnel theory
- when a witness’ attention narrows to focus on a weapon because it is the source of anxiety
- leads to weapon-focus effect where tunnel focus negatively affects recall of event
supporting evidence for anxiety affecting EWT - Johnson and Scott
- participants in waiting area
- in low anxiety situation, a discussion was overheard in the laboratory followed by a man leaving the lab holding a pen and grease on his hands
- in high anxiety condition, a discussion was overheard in the lab including breaking glass and crashing chairs, followed by man leaving lab carrying paper knife and blood
- 49% identified man holding pen
- 33% identified man with knife
supporting evidence for anxiety affecting EWT -Yuille and Cutshall
- study of real life shooting in Vancouver
- interviews 4-5 months after crime
- witnesses rated how stressed they were at the time of crime
- participants with highest levels of stress were more accurate (88% compared to 75%)
undermining evidence for anxiety affecting EWT - Johnson and Scott testing surprise
- tested surprise rather than anxiety
- Pickel conducted experiment using scissors, handgun, wallet or chicken in a hairdressing salon
- found that eyewitness accuracy was poorer in high unusualness conditions (chicken and handgun)
weakness of anxiety affecting EWT - interview after long time
- field/natural experiments- researchers interview witnesses some time after event
- EVs happened in between such as post-event discussion, interviews from police, media reports
- so studies cant provide strong support
weakness of anxiety affecting EWT- participants aware of fake crime
- staged crime showed to participants who are aware
- demand characteristics- participants will pay more attention than normal
- less internally valid results
cognitive interview
method of interviewing eyewitnesses to help them retrieve more accurate memories using 4 techniques based on psychological insights
report everything
witness is encouraged to include every single detail of the event, even if they seem irrelevant or trivial
reinstate the context
the witness returns to original crime scene in their mind and imagine their environment and emotions. then asked to describe what they saw
reverse the order
Events should be recalled in a different chronological order to the original sequence
change perspective
Witnesses should recall the incident from the perspective of some else e.g. another witness or the perpetrator
why is report everything important
Witnesses might not realise that some details are important, and these may trigger (act as cues for) other important memories, leading to more accurate testimonies.
why is reinstate the context important
Recalling how you felt and the environment could enhance recall by preventing context-dependent and state-dependent forgetting
why is reverse the order important
This is to prevent people from reporting their expectations of how the event must have happened rather than the actual events. It also prevents dishonesty as it’s harder to lie when you have to explain something backwards.
why is change the perspective important
This disrupts the effect of expectations and schema on recall. The schema you have for a particular setting (e.g. going into a shop) generate expectations of what would have happened and it is the schema that is recalled rather than what actually happened.
supporting evidence for cognitive interview- Milne and Bull
-found that using report everything and reinstate the context produced better recall
- so some aspects of the CI are more useful
- so these elements improve police interviewing
-
weakness of cognitive interview
- police may not use CI because it is time-taking and requires special training
- means it is unlikely that CI has been used which explains why police thought it is not effective
weakness of studies of cognitive interviews- some used enhanced
- studies of effectiveness of CI use slightly different variations of CI/ some use enhanced
- so it is difficult to evaluate the CI because a true comparison cant be made
supporting and undermining evidence of cognitive interviews - Kohnken et al.
- meta-analysis comparing enhanced CI and CI to standard interview
- enhanced CI provided more correct info and incorrect info than standard
- real life practical benefits to police using enhanced CI as gives police higher chance of catching criminal
- also increases incorrect info so testimonies still incorrect
