EWT: Anxiety Flashcards
Anxiety: Negative Effect on EWT
Procedure
Johnson and Scott (1976)
- Participants believed they were taking part in a lab study.
- While seating in the waiting room, participants in the low-anxiety condition heard a casual conversation in the next room, then saw a man walk past them holding a pen and with grease on his hands.
- The high-anxiety condition heard a heated argument, accompanied by the sound of broken glass. A man exits the room holding a knife covered in blood.
Anxiety: Negative Effect on EWT
Findings
Johnson and Scott (1976)
- The participants later picked out the man from a set of 50 photos, 49% of the low-anxiety were able to identify him.
- The corresponding figure for the high-anxiety condition was 33%.
- 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.
Anxiety: Positive Effect on EWT
Procedure
Yuille and Cutshall (1986)
- Conducted a study on an actual shooting in a gun shop in Vancouver: the shop keeper shot a thief dead.
- There were 21 witnesses, 13 agreed to participate in the study.
- They were interviewed four to five months after the incident and these interviews were compared with the original police interviews at the time of the shooting.
- Accuracy was determined by the number of details reported in each account.
- The witnesses were also asked to rate how stressed they had felt during the incident (7-point scale) and whether they had any emotional problems since the incident (e.g. sleeplessness).
Anxiety: Positive Effect on EWT
Findings
Yuille and Cutshall (1986)
- The witnesses were very accurate in their accounts and there was little change in the amount recalled after 5 months.
- Some details were less accurate, such as recollection of the colour of items, the age/height/weight estimates.
- Those participants who reported the highest levels of stress were most accurate (about 88% compared to 75% for the less-stressed group).
- This suggests anxiety does not have a detrimental effect on the accuracy of eye-witness testimony and may even enhance it.
Anxiety: Effects on EWT
Explaining Contradictory Findings
Deffenbacher (1983)
- According to Yerkes and Donson (1908), the relationship between emotional arousal and performance looks like an inverted-U.
- Deffenbacher (1983) reviewed 21 studies and noted the contradictory findings on the effects of anxiety.
- He used Yerkes-Donson law to explain these findings:
- When we witness a crime/accident, we become emotionally and physiologically aroused.
- Lower levels of anxiety/arousal produce lower levels of recall accuracy and it becomes more accurate as the level of anxiety/arousal increases.
- There is an optimum level of anxiety where recall is at maximum accuracy.
- If a person experiences too much anixety, their recall suffers a drastic decline.
Anxiety: Evaluation
Unusualness, not Anxiety
Limitation
- Johnson and Scott’s study may not have tested anxiety.
- Participants may have focused on the weapon because they were surprised at what they saw.
- Pickel (1998) conducted an experiment using scissors, a handgun, a wallet or a raw chicken as the hand-held items in a hairdressing salon video.
- Scissors acted as ‘high anxiety, low unusualness’; raw chicken as ‘low anxiety, high unusalness’.
- Eyewitness accuracy was signficantly poorer in the high unusualness conditions.
This suggests that the weapon focus effect is due to unusualness rather than anxiety. This therefore tells us nothing about the effects of anxiety on EWT.
Anxiety: Evaluation
Support for Negative Effects
Strength
- There is evidence supporting the view that anxiety has a negative effect on recall.
- In an experiment, researchers used an objective measure (heart rate) to divide participants into high and low anxiety groups.
- In this study, anxiety clearly disrupted the participants’ ability to recall details about the actor in the London Dungeon’s Labyrinth.
This suggests that high levels of anxiety does have a negative efffect on the immediate recall of a stressful event.
Anxiety: Evaluation
Support for Positive Effects
Strength
- There is evidence showing that anxiety can have a postive effect on EWT.
- Christianson and Hubinette (1993) interviewed 58 witness to actual bank robberies in Sweden.
- Some were directly involved (banl workers) and others were indirectly involved (bystanders).
- The researchers assumed those most involved experienced the most anxiety.
- Recall was 75% across all witnesses; the direct victims (most anxious) were even more accurate.
These findings from actual crimes confirm that anxiety does not reduce the accuracy of recall for eyewitnesses and may even enchance it
Anxiety: Evaluation
Counterpoint
(Support for Positive Effects)
- Christianson and Hubinette interviewed their participants several months after the event (4-15 months).
- The researchers therefore had no control over what had happened to their participants in the interviening time (e.g. post-event discussion).
- The effects of anxiety may have been overwhelmed by other factors and is impossible to access.
Therefore, it is possible that a lack of control over confounding variables may be responsible for these findings, invalidating their support.
