eyewitness testimony Flashcards
what is an eyewitness testimony?
the ability of people to remember the details of events, such as accidents and crimes which they have observed. Accuracy affected by leading questions, anxiety and post-event discussion
what are leading questions?
questions that are phrased in such a way that make it likely that a witnesses’ schema will influence them to five a desired answer or interpretation of event.
Loftus and Palmer method
- lab experiment
- 45 American Students from Washington
- shown seven films of car accidents
- 9 participants in each condition
- asked about the speed of the car when the smashed, collided,hit,bumped,contacted each other
loftus and palmer results
contacted - 31.8
smashed - 40.8
- associate a more severe verb with a higher speed. misleading information distored the participant’s memory.
loftus + palmer evaluation (strength)
- practical use (leading questions can have distorting effect on memory, police need to be careful in wording, make important positive different to lives, more wrongful convictions
loftus + palmer (weakness)
- low eco validity, doesn’t test memory in realistic way
- watched films of car accidents + witnessed from start to finish, different from real accident. clips lack stress and rare to witness whole crash
- results don’t reflect everyday car accidents, may have shown stronger emotional connection + not affected by LQ the same
c-c = high levels of control over extraneous variables due to controlled setting controlled clips watched, increases internal validity
loftus + palmer (weakness)
- lacks population validity
- 45 american psychology students from uni of washington
- students less experienced drivers who may be less accurate at estimating speeds
- psych students more inclined to show demand characteristics, understanding of psych research
- unable to generalise results to other populations such as experienced drivers and older people, non-psychology students
what is post-event discussion?
occurs when there is more than one witness to an event. witnesses may discuss what they have seen with co-witnesses or with other people, influence the accuracy of recall
Gabberts method
- 60 aberdeen uni students + 60 older adults from local community centre
- watched vid of girl stealing money from wallet
- individually tested or in pairs (co-witnesses)
- co-witnesses discussed + completed questionnaire (had watched different perspectives)
Gabberts findings
- 71% of co-witness group recaleld info not seen
- 60% said girl was guilty, hadnt seen her actually commit a crime
Gabbert - practical use
- has a practical use in the real world, where there are some very real consequences of inaccurate EWT.
- Research has highlighted that post-event discussion can have such a distorting effect on memory that police officers need to bear this in mind when interviewing eyewitnesses who have discussed the crime before their interview with the police.
- Research into EWT can make an important positive difference to the lives of real people, improving the way the legal system works and appearing in court trials as expert witnesses.
Gabbert - high control
- Gabbert’s research took place in a lab and was therefore highly controlled.
e.g. Gabbert used standardised procedures such as using the video clip of the theft for all participants.
-This high degree of control reduces the chance of extraneous variables - increasing the validity of the results.
- Therefore, we are able to see a cause and effect relationship between the IV (whether participants were tested individually or in pairs) and the DV (recall accuracy).
Gabbert - low eco val
-low ecological validity as the method that Gabbert used is not testing memory in a realistic and meaningful way.
- Participants watched a video clip of a girl stealing money and witnessed the events unfold from start to finish.
- This is a very different experience from witnessing a real theft, mainly because such clips lack the stress of a real crime, and rarely would witnesses see the whole event.
- Therefore, these results do not reflect every day thefts and we are unable to conclude if eyewitnesses to real crimes, who would have a stronger emotional connection to the event, would be susceptible to post-event discussion in the same way.
what is anxiety?
a state of physical and emotional arousal. the emotions include worries and feelings of tension. increased heart rate + sweatiness. Can affect accuracy of EWT
Johnson + Scott method
- participants believed they were taking part in lab study, overheard convo in the next room
- ‘low anxiety’/’no weapon’ condition = overheard convo in the lab about equipment failure, man walked out with pen with grease on hands
- ‘high anxiety’/’weapon’ = overheard same convo, sound of breaking glass, individual running into reception with bloodied knife
johnson + scott findings
- participants identified man out of 50 photos
- 49% = identifed man with pen
- 33% = identified man with knife
- weapon-focus effect
johnson + scott limitation (pickel)
- pickel proposed reduced accuracy of identification was due to surprise rather than anxiety
- participants watched thief enter salon carrying scissors, wallet, handgun or whole raw chicken
- identification least accurate in high surprise (chicken)
- supports view that weapon-focus effect is related to surprise rather than anxiety
johnson + scott limitation (ethics)
- protection of participants and deception broken
- exposed some participants to a man holding a bloodied knife, may have caused extreme anxiety + distress
- participants may have left experiment feeling stressed + anxious, especially is personal experience with knife crime
- damages reputation of psychology
johnson + scott limitation (yuille + cutshall)
- Yuille and Cutshall’s real life case study contradicts results
- 13 people who witnessed real shooting, 1 person died and 1 wounded
- accurate in their EW accounts 5 months later, major details were the same
- in real-life cases of anxiety, accuracy of EWT not affected
C-C = based off of one case, lacks generalisability to eyewitnesses of all cases
contradictory anxiety findings
- yerkes-dodson law suggests that moderate anxiety is associated with better recall than high or low anxiety, increases alertness
what is the cognitive interview?
a method of interviewing eyewitnesses to help them retrieve more accurate memories. it uses four main techniques, based on knowledge of memory: report everything, reinstate the context, recall in reverse order and recall from changed perspective
report everything
- witnesses encouraged to report every detail of the event
- trivial details may be important
- may trigger other important memories
‘fully describe the incident’
reinstate the context
- when a person mentally recalls the context of the event
- might recall the time of day, weather, feelings
- details can act as trigger for more information, linked to state-dependent and context-dependent forgetting
‘describe the surroundings you were in during the incident’
recall in reverse order
- events should be recalled in different chronological order than original sequence
- prevents people from reporting their expectation of how the event occurred rather than actual events
- prevents dishonest
‘starting at the very end and working backwards, describe the incident’
recall from changed perspective
- witnesses should recall the incident from other people’s perspectives
- might consider what the offender saw
- disrupt expectations and schema on recall
‘imagine somebody else witnessed the incident. How do you think they would describe the incident?’
CI - research support
- research support suggests its effectiveness
- Geiselman found that students interviewed using CI recalled significantly more info than those interviewed using standard interview
- number of errors similar
- CI is effective in improving quantity of information recalled and doesn’t lead to increase in incorrect information
CI - police (time)
- police may be reluctant to use CI because takes much more time than standard police interview
- more time needed to establish a rapport with the witness and allow them to relax. CI also requires specialist training and many not been able to provide enough time
- unlikely that proper version of the CI is actually used, may explain why police not impressed with it
CI - Reece
- although increases quantity of info recalled, still susceptible to misleading information
- reece showed participants a vid of a bank robbery and then gave participants a misleading or neutral post-event summary
- participant in both condition equally susceptible to misleading information
- interviewers need to be careful that participants aren’t exposed to MI in form of leading questions or post-event discussion
