Eyewitness accuracy - anxiety Flashcards
Anxiety definition
A state of emotional and physical arousal
Physical changes from anxiety
Increased heart rate and sweating
Anxiety has a negative effect on EWT
Reduce accuracy and detail
Weapon focus - Physiological arousal in the body prevents us from paying attention to important cues - recall is worse
The weapon creates anxiety which reduces the witness’s recall of the event
Research for negative effect on EWT
Johnson and Scott (1976)
Procedure:
Participants believed they were taking part in a lab experiment and were seated in the waiting room
Two groups:
High-anxiety condition - overhead a heated argument, smashed glass and a man walking out of the room with a knife, covered in blood
Low-anxiety condition - overheard a casual conversation and then a man walking out of the room carrying a pen with grease on his hands
Findings and Conclusion:
The participants were then showed 50 photo and they had to pick out the man they saw
49% who had seen the man carrying a pen were able to identify them
33% were able to identify the man with the knife/blood
The tunnel theory of memory argued that people have enhanced memory for central events - weapon focus as a result of anxiety can have this effect
Anxiety has a positive effect on recall
Witnessing a stressful event creates anxiety through physiological arousal within the body
Fight or flight is triggered - this may improve memory as we become aware of cues in the situation
Research for anxiety having a positive effect
Guile and Cutshall (1986)
Procedure:
Study of an actual shooting in a gun shop in Vancouver, Canada
The shop owner shot the thief deaf
21 Witnesses - 13 took part in the study
They were interviewed 4/5 months after the event and these interviews were compared to the original police interviews
Accuracy measured - number of details reported in each account
Had to rate how stressful the incident was (7 point scale) and whether they has had any emotional problems (e.g. sleeplessness)
Findings:
Witnesses were very accurate and very little changed in recall - some details were less accurate (colours, age, height, weight)
Those who reported the highest levels of stress were most accurate
-This suggested that anxiety does not have a detrimental effect on the accuracy of eyewitness memory and may even enhance it
Inverted U theory people/date
Yerkes and Dobson (1908)
Research support for inverted U theory
Deffenbacher (1983) reviewed 21 studies of EWT and noticed contradictory findings of the effects of the anxiety
Used Yerkes and Dobson’s laws to explain
Limitation of Johnson and Scott’s study
-Unusualness not anxiety, may not have test anxiety
-Focusing on the object being carried may have been surprised rather than being scared
Kerri Pickel (1998) conducted an experiment in a hairdressers using the following four items - a handgun, a wallet, scissors and a raw chicken
High anxiety, low unusualness = scissors
High unusualness = chicken/handgun
Eyewitness accuracy was significantly poorer in the high unusualness conditions - chicken and a handgun
This suggests that the weapon focus effect is due to unusualness rather than anxiety
Support for Johnson and Scott
Tim Valentine and Jan Mesout (2009) supports the research on weapon focus
They used an objective measure (heart rate) to divide participants into low and high anxiety level groups. In the study anxiety disrupted the participants ability to recall details about the actor in the London Dungeon
Therefore, high levels of anxiety do have a negative effect on the immediate eyewitness recall of a stressful event
Support for Yuille and Cutshall
Sven-Ake Christianson and Birgitta Hubinette (1993):
Interviewed 58 witnesses to actual bank robberies in Sweden
Some witnesses were directly involved (e.g. bank worker) and others were indirectly involved (e.g. bystander)
The researchers assumed (hypothesised) that those directly involved would experience the most anxiety
The direct victims (experiencing higher anxiety) were even more accurate
Findings from actual crimes
Show that anxiety does not reduce the accuracy of recall and may even enhance it
Counterpoint for support for Yuille and Cutshall
Christianson and Hubinette interviewed their participants several months after the event had taken place - between 4 and 15 months
The researchers had no control over the participants in this time - post-event discussion/news reports
Therefore the effects of anxiety may have been overwhelmed by other factors and impossible to accurately access
Therefore it is possible that a lack of control over confounding variables may be responsible for the findings, invalidating the research
