memory 1.5 Flashcards
Factors affecting the accuracy of eyewitness testimony: misleading information, including leading questions and post-event discussion; anxiety.
when are leading questions used?
(used by the police of barristers/lawyers during a criminal trial) may lead to unreliable EWT being given and, ultimately, an innocent person being convicted
leading question
a question that suggests or leads to a desired response due to the wording of it
e.g. “did you see the knife?” opposed to “did you see a knife?”
response-bias explanation
wording of a question has no enduring effect on an eyewitness’ memory of an event, but influences the kind of answer given
substitution explanation
wording of a question does affect eyewitness’ memory, distorting its accuracy
misleading information
defined as information given to someone as part of a question that may change the way they perceive a situation or an event
it can take many forms including leading questions or post-event discussion
weapon focus
eyewitnesses who focus on a weapon during a crime are more likely to make mistakes in their recall of other details, such as the perpetrator’s face.
own-race bias
eyewitnesses are more likely to accurately identify someone of their own race than someone of a different race
cross-race identification
eyewitnesses are more likely to make mistakes when identifying someone of a different race.
who researched into the effects of misleading questions on EWT?
Loftus and Palmer (1974)
what was Loftus and Palmer (1974)’s aim?
investigate the effects of misleading information on EWT
what was Loftus and Palmer (1974)’s procedure?
45 student participants were shown 7 short video clips of cars colliding
they were split into 5 groups
all participants were asked “About how fast were the cars going when they … each other?”
the verbs to fill in the blank were either:
smashed
collided
bumped
hit
contacted
what were Loftus and Palmer (1974)’s results?
in mph:
smashed - 40.8
collided - 39.3
bumped - 38.1
hit - 34
contacted - 31.8
what was Loftus and Palmer (1974)’s conclusion?
the phrasing of the question influenced the participants’ speed estimates
the more powerful the verb, the quicker the speed
who researched into the effects of leading questions on EWT?
Loftus and Zanni (1975)
what was Loftus and Zanni (1975)’s aim?
investigate the impact of leading questions on EWT
what was Loftus and Zanni (1975)’s procedure?
participants were 100 university students and were all informed they were completing a study on memory
they were shown a one minute film of a car crash
they were then asked a leading question:
“did you see the broken headlight?”
“did you see a broken headlight?”
what were Loftus and Zanni (1975)’s results?
the following percentages were the people claiming to have seen a broken headlight:
“did you see the broken headlight?” - 17%
“did you see a broken headlight” 7%
what was Loftus and Zanni (1975)’s conclusion?
the changing of a simple word as part of a leading question can impact participants’ recall
explain how research into misleading information regarding eyewitness testimony can be applied to real life
this research shaped the cognitive interview as the cognitive interview is designed to avoid leading questions and instead get witnesses to report everything
therefore it has application
explain how Loftus and Palmer (1974)’s research lacks internal validity
watching film clips of car crashes is not at all like witnessing a real accident
e.g. a lack of emotional / dramatic content
participants get all the same view of the accident rather than seeing it from different vantage points
therefore it lacks internal validity
post-event discussion
a potential source of misleading information where witnesses discuss what they saw after an event
conversations after the event can have a similar impact to leading questions as false information can be added in where people can mistake other people’s memories for their own
who researched into the impact of post-event discussion on EWT?
Gabbert et al (2003)
what was Gabbert et al (2003)’ aim?
to investigate the impact of post-event discussion on EWT
what was Gabbert et al (2003)’s procedure?
sample consisted of 60 students from the University of Aberdeen and 60 older adults from a local community
participants watched a video of a girl stealing money from a wallet
the participants were either tested individually (control group) or in pairs (co-witness group)
participants in the co-witness group were told that they had watched the same video, however they had in fact seen different perspectives of the same crime and only one person had actually witnessed the girl stealing in the pair
participants in the co-witness group discusses the crime together
all of the participants then completed a questionnaire testing their memory of the event
what were Gabbert et al (2003)’s results?
they found that 71% of the witnesses in the co-witness group recalled information they had not actually seen and 60% said that the girl was guilty, despite the fact they hadn’t seen her commit a crime
what was Gabbert et al (2003)’s conclusion?
these results highlight the use of post-event discussion and the powerful effect this can have on the accuracy of EWT
anxiety
an emotion characterised by feelings of tension, worried thoughts and physical changes like increased blood pressure
Yerkes-Dodson Law
this inverted - U theory states that performance will increase with stress, but only up to a certain point, where it decreases drastically
low arousal = poor performance
high arousal = high performance
the relationship between performance and stress/arousal is inverted
Deffenbacher (1983)
reviewed 21 studies of EWT with contradictory findings on the effects of anxiety on recall
he suggested the Yerkes-Dodson effect could explain this
both low and higher levels of anxiety produce poor recall whereas optimum levels lead to very good recall
who’s research found that anxiety has a negative effect on recall?
Johnson and Scott (1976)
what was Johnson and Scott (1976)’s aim?
to investigate the effects of anxiety on recall
what was Johnson and Scott (1976)’s procedure?
participants sat in a waiting room believing they were going to take part in a lab study
participants heard a discussion in a room nearby then the following happened depending on the group they were in:
condition A (low anxiety) - a man came out of the room with a pen and grease on his hands
condition B (high anxiety) - a man came out of the room carrying a knife covered in blood
participants were then asked to identify the man from 50 photographs
what were Johnson and Scott (1976)’s results?
condition A (low anxiety) - 49% accurate at identifying the man
condition B (high anxiety) - 33% accurate at identifying the man
what was Johnson and Scott (1976)’s conclusion?
when anxious and aroused, witnesses focus on a weapon at the expense of other details
who’s research found that anxiety has a positive effect on recall?
Yullie and Cutshall (1986)
what was Yullie and Cutshall (1986)’s aim?
the investigate the effects of anxiety on EWT
what was Yullie and Cutshall (1986)’s procedure?
in an actual crime, a gun shop owner shot a thief dead
there were 21 witnesses, 13 agreed to participate in the study
participants were interviewed 4-5months after the incident
the information recalled was compared to the police interviews at the time of the shooting
witnesses rated how stressed they felt at the time of the incident
what were Yullie and Cutshall (1986)’s results?
witnesses were very accurate in what they recalled and there was little change after 5 months
some details were less accurate e.g. age/weight/height
participants who reported the highest levels of stress were most accurate (about 88% compared to 75% for the less stressed group)
what was Yullie and Cutshall (1986)’s conclusion?
anxiety does not appear to reduce the accuracy of EWT for a real world event and may enhance it
explain the limitation that anxiety may not be relevant to weapon focus
Johnson and Scott’s participants may have focused on the weapon not because they were anxious, but because they were surprised
Pickel (1998) found accuracy in identifying the ‘criminal’ was poorest when the object in their hand was unexpected e.g raw chicken and a gun in a hairdressers (both unusual)
this suggests the weapons effect is due to unusualness rather than anxiety/threat and so tells us nothing about the specific effects of anxiety on recall
explain how the supporting evidence for the negative effects of anxiety on EWT is a strength
Valentine and Mesout (2009) used heart rate which is an objective measure to divide visitors to the London Dungeon’s Labyrinth into low and high anxiety groups
high anxiety participants were less accurate than low anxiety in describing and identifying a target person
this therefore supports the idea that anxiety has a negative effect on immediate eyewitness recall of a stressful event
explain how supporting evidence for positive effects of anxiety on EWT is a strength
Christianson and Hubinette (1993) interviewed actual witnesses to bank robberies, some were direct victims (high anxiety) and others were bystanders (less anxiety)
they found more than 75% accurate recall across all witnesses. direct victims (most anxious) were even more accurate
this suggests that anxiety does not affect the accuracy of EWT recall and may even enhance it
counterpoint to how supporting evidence for positive effects of anxiety on EWT is a strength
Christianson and Hubinette interviewed witnesses long after the event
many things happened that the researchers couldn’t control e.g. post-event discussion
therefore, lack of control over confounding variables may be responsible for the (in)accuracy of recall ,not anxiety
explain how problems with the inverted U theory is a limitation of research into the effects of anxiety on recall
the inverted-U theory appears to be a reasonable explanation of the contradictory findings linking anxiety with both increased and decreased eyewitness recall
however, it only focuses on physical anxiety and ignores other elements, including cognitive (how we think about a stressful events affects recall)
therefore, the inverted-U explanation is probably too simplistic to be useful e.g. anxious thoughts may not always leas to symptoms of anxiety but may block memory
