factors effecting the accuracy of eyewitness testimony-anxiety Flashcards
anxiety definition
a state of emotional and physical arousal. the emotions include having worried thoughts and feelings of tension. physical changes include and increases heart rate and sweatiness. anxiety is a normal reaction to stressful situations, but it can affect the accuracy and detail of eyewitness testimony
what effects does anxiety have
strong physical and emotional
what effect does anxiety have on accuracy of eyewitness testimony
unclear if it makes eyewitness recall better or worse as there is research supporting both possibilities
which focus study shows anxiety to have negative effect on recall
weapon focus
why does anxiety decrease accuracy of eyewitness testimony
creates physiological arousal in the body which prevents us paying attention to important cues, so recall is worse
how does weapon focus work
an approach to studying accuracy of eyewitness testimony is to look at effect of a weapon which creates anxiety, this leads to focus on the weapon, reducing witness’s recall for other details of the event
who did research for anxiety having a negative effect on recall (weapon focus)
Johnson and Scott
when did Johnson and Scott do research for anxiety having a negative effect on recall (weapon focus)
1976
in Johnson and Scott’s research for anxiety having a negative effect on recall (weapon focus) procedure
participants believed they were taking part in a lab study. there was a low-anxiety and a high-anxiety condition. the in low-anxiety condition participants were seated in a waiting room and heard a casual conversation in next room and saw a man walk past carrying a pen with grease in his hands. in high-anxiety condition, participants heard a heated argument accompanied by the sound of broken glass, a man walked out the room holding a knife covered in blood
what were the 2 conditions in in Johnson and Scott’s research for anxiety having a negative effect on recall (weapon focus)
-high-anxiety
-low-anxiety
what was the high anxiety condition for in Johnson and Scott’s research for anxiety having a negative effect on recall (weapon focus)
participants overheard a heated argument accompanied by the sound of broken glass. a man walked out the room holding a knife covered in blood
what was the low-anxiety condition in Johnson and Scott’s research for anxiety having a negative effect on recall (weapon focus)
participants overheard a casual conversation and saw a man walk past carrying a pen with grease on his hands
in Johnson and Scott’s research for anxiety having a negative effect on recall (weapon focus) findings
participants later picked the man out of a set of 50 photos 49% who saw man carrying the pen were able to identify him. 33% were able to recognise the man holding the knife
in Johnson and Scott’s research for anxiety having a negative effect on recall (weapon focus) conclusion
the tunnel theory of memory argues that people have enhanced memory for central events. weapon focus as a result of anxiety can have this effect
what is tunnel theory of memory
people have an enhanced memory for central events
what focus can have tunnel theory of memory
weapon
why does anxiety have a positive effect on recall
witnessing a stressful event creates anxiety through physiological arousal within the body. the fight or flight response is triggered, increasing alertness. this may improve memory as are more aware of cues in the situation
who did research for anxiety having a positive effect on recall
Yuille and Cutshall
when did Yuille and Cutshall research anxiety having a positive effect on recall
1986
Yuille and Cutshall research anxiety having a positive effect on recall procedure
study of an actual shooting in a gun shop in Vancouver, Canada. the shop owner shot a thief dead. there were 21 witnesses and 13 took part in the study, they were interviewed 4/5 months after incident and interviews were compared with the original police interviews taken at the time. accuracy was determined by number of details reported in each account. witnesses were asked to rate how stressed they felt at the time of incident on a 7-point scale and if they had had emotional problems since
Yuille and Cutshall research anxiety having a positive effect on recall findings
witnesses were very accurate in accounts and there was little change in amount of recall after 5 months, although some details such as age/height/weight estimates were less accurate participants how recorded highest amount of stress had more accurate recall of 88% compared to 75% for less stressed group
Yuille and Cutshall research anxiety having a positive effect on recall witness and how many took part
21 witnesses and 13 took part on study
Yuille and Cutshall research anxiety having a positive effect on recall how long after event were participants interviewed
4-5 months
Yuille and Cutshall research anxiety having a positive effect on recall how was accuracy determined
number of details reported in each account
Yuille and Cutshall research anxiety having a positive effect on recall how was stress measured
asked to rate how stressed they felt at time of incident on 7-point scale and if they had emotional problems since
Yuille and Cutshall research anxiety having a positive effect on recall conclusion
suggests anxiety does not have a detrimental effect on the accuracy of eyewitness testimony in real-world context and may enhance it
how did Yerkes and Dodson explain contradictory findings (1908)
inverted u
what relationship looks like an inverted u
relationship between arousal and performance
who described relationship between arousal and performance as an inverted u
Yerkes and Dodson
how many studies of EWT did Deffenbacher (1983) use
21
when did Yerkes and Dodson explain contradictory findings
1908
when did Deffenbacher review studies of EWT
1983
how did Deffenbacher explain contradictory findings of anxietys effect on accuracy of EWT
reviewed 21 studies on EWT and noted contradictory findings on effects on anxiety. he used yerkes-dodson law to explain findings. when we witness a crime/accident we become emotionally and physiologically aroused. we experience anxiety (emotional) and physiological changes (fight or flight). lower levels of anxiety/arousal produce lower levels of recall accuracy, then memory becomes more accurate as level of anxiety increases. however, there is an optimum level of anxiety which is the point of maximum accuracy. is a person experiences more anxiety their recall will drastically decline
limitation of anxiety effecting accuracy of EWT - unusualness not anxiety
-limitation of Johnson and Scott study is may have not tested anxiety
-participants may have focused on the weapon as they were surprised about what they saw, not sacred. Pickel (1998) conducted an experiment using scissors, a handgun, a wallet or raw chicken as the hand-held items in a hair dressing salon (scissors are low anxiety, low unusalness). eyewitness accurac y was significantly poorer in high unusuallness conditions of chicken and handgun –> suggests weapon focus effects is dues to unusualness rather than anxiety and tells us nothing about effects of anxiety on EWT
support for negative effects of anxiety effecting accuracy of EWT
-evidence supporting view that anxiety has a negative effect on accuracy of recall
-valentine and Mesout (2009) supports weapon focus finding negative effects on recall. the researchers used an objective measure (heart rate) to divide participants into high and low anxiety groups. in this study anxiety is clearly disrupted participants ability to recall details about actor in London Dungeon’s Labyrinth –> suggests high level of anxiety does have a negative effect on immediate eyewitness recall of a stressful event
strength of anxiety effecting accuracy of EWT - support for positive effects
-evidence showing anxiety can have a positive effect on accuracy of recall
-Christianson and Hubinette (1993) interviewed 58 witnesses to actual bank robberies in Sweden, some were directly involved (bank workers) and some were indirectly involved (bystanders), research assumed those directly involved would have the most anxiety. found that recall was more than 75% accurate across all witness, direct victims were even more accurate
–> findings from actual crimes confirm anxiety does not reduce accuracy of recall for eyewitnesses and may even enhance it
limitation of anxiety effecting accuracy of EWT- counterpoint for support for positive effects
-Christianson and Hubinette interviewed participants several months after the incident (up to 15 months) the researchers had no control over what happened to participants in intervening times such as post event discussion. effects on anxiety may have been overwhelmed by these other factors and impossible to assess by the time participants were interviewed –> lack of control of confounding variables may be responsible for these findings, invalidating their support
evaluation of anxiety effecting accuracy of EWT - problems with inverted-U theory
s- inverted U theory seems to be a reasonable explanation of contradictory findings linking anxiety with both increased and decreased eyewitness recall
l- however, it ignores instances that anxiety has many elements - cognitive, behavioral, emotional and physical. it just focuses on physical arousal and assumes only aspect linked to EWT, but they way we think (cognitive) in stressful situations may also be important
where did Valentine and Mesout carry out study
London Dungeon which is designed with many ‘scares’ for visitors such as darkness, screams, gory models and sudden movements
what were Valentine and Mesout participants offered
reduced entrance fee if they completed questionaire at the end to assess their level of self-reported anxiety
what did Valentine and Mesout participants wear
wireless heart rate monitors to confirm they were actually experiencing anxiety on these 2 measurements participants were divided into high and low anxiety groups
how did Valentine and Mesout participants recall
described a person encountered in Labyrinth
what did Valentine and Mesout find
high-anxiety participants recalled the fewest correct details of actor and made more mistakes. 17% high anxiety correctly identifies actor in line compared to 75% correct identification in those low anxiety groups
