Anxiety on EWT Flashcards
What is anxiety?
A state of emotional/physical arousal
What is the Yerkes-Dodson law?
States that extreme anxiety (too high or too low) reduces EWT accuracy and moderate anxiety enhances EWT accuracy
What is the weapon focus effect?
A weapon in a criminal’s hand distracts attention from other features (because of the anxiety it creates) and therefore reduces the accuracy of identification of the perpetrator in a crime
Name 2 studies that suggest anxiety has a positive impact on EWT
Yuille and Cutshall (1986) - Canadian robbery
Christianson and Hubinette (1993) - Swedish Bank robbery
Outline the study that shows positive effect of anxiety (banks)
Christianson (Christian and his son are swedish people who like the bank) and HubiNETte (thinks anxiety is positive and that its not a NET) (1993):
Questioned 58 real witnesses to Swedish bank robberies. Witnesses were either victims (bank teller= high anxiety) or bystanders (employee/customer= low anxiety). Interviews were conducted 4-5 months after robberies. It was found that all witnesses had good memories for details of robbery and the most anxious witnesses (victims) has the best recall
Outline the study that shows positive effect of anxiety (gun)
Yuille and Cutshall (shall like shell for a gun) (1986):
Real-life shooting in a Canadian gun shop where shop owner shot thief dead. Witnesses were interviewed 3-5 months later and compared with the original police interview made at the time of shooting. Witnesses were asked to rate how stressed they had felt at time of incident.
It was found that witnesses accounts were very accurate and there was little change in accuracy after 5 months. Participants with highest stress were most accurate (about 88% compared to 75% for less-stressed group)
Evidence for anxiety decreasing accuracy of EWT
Johnson and Scott (1976): (Plain office names)
Participants were asked to wait in a reception area of a lab where they overheard an argument in the next room before a man leaves the room. There were two conditions:
- Low anxiety condition. participants overheard argument in lab and man walks out holding a pen, with hands covered in grease
- High anxiety condition. participants overheard heated argument, sound of breaking glass and crashing chairs before a man runs out holding bloodied letter opener
Both groups were shown 50 photos and asked to identify the man they saw leaving the room. Findings showed 49% accuracy in the low anxiety condition and 33% accuracy in high anxiety condition
1 Strength of anxiety on EWT and counter
Support from real-life studies:
Yuille and Cutshall and Christianson and Hubinette (1993) both carried out in the context of a real crime. This creates the real levels of anxiety experienced by an eye witness during a real crime. High external validity. COUNTER - Lower internal validity. Researcher loses control in those three months and participants could by influenced by the media or post-event discussion.
2 Limitations of anxiety on EWT
Focus on weapon not caused by anxiety:
Pickel (cut the pickel and chicken with scissors) (1986) arranged participants to watch a thief enter a hair salon with either scissors (high threat, low surprise), a handgun (high threat, high surprise), a wallet (low threat, low surprise) or raw chicken (low threat, high surprise). Identification of man least accurate in high surprise rather than high threat. This suggests that the weapon focus effect is related to surprise and unusualness rather than anxiety / threat and thus contradicts the idea that it is anxiety which reduces the accuracy of eyewitness testimony, therefore limiting the reliability of weapon focus effect
Problems with the Yerkes Dodson law:
However, it ignores the fact that anxiety has many elements – cognitive, behavioural, emotional and physical. It focuses solely on the idea of physical arousal and assumes this is the only aspect linked to EWT, but the interconnection of the elements of anxiety is likely to cumulatively cause anxiety, not just the physical element alone.
Alternative explanations consider the affects of different types of anxiety. Fazey and Hardy (1988) proposed the catastrophe theory which explains how anxiety affects EWT on a three-dimensional scale. As somatic arousal (physiological) increases, so does the quality of performance but when high somatic arousal clashes with high cognitive arousal (psychological) there is a sudden dramatic drop.
