MEM 12 - EWT anxiety Flashcards
What is anxiety?
- A state of emotional and physical arousal
- The emotions include having worried thoughts and feelings of tension
- Physical changes include an increased heart rate and sweatiness
- Anxiety is a normal reaction to stressful situations, but it can affect accuracy and detail of eyewitness testimony
Who conducted research on anxiety having a negative effect on recall?
Craig Johnson and William Scott (1976)
What was the procedure for the research on anxiety having a negative effect on recall (weapon focus)?
- Craig Johnson and William Scott (1976) did research on this
- Their participants believed they were taking part in a lab study
- While seated in a waiting room participants in the low-anxiety condition heard a casual conversation in the next room and then saw a man walk past them carrying a pen and with grease on his hands
- Other participants overheard a heated argument, accompanied by the sound of breaking glass. A man walked out of the room, holding a knife covered in blood
- This was the high-anxiety condition
What were the findings for the research on anxiety having a negative effect on recall (weapon focus)?
- The participants later picked out the man from a set of 50 photos, 49% who had seen the man carrying the pen were able to identify him
- The corresponding figure for the participants who had seen the man holding the blood-covered knife was 33%
What was the conclusion for the research on anxiety having a negative effect on recall (weapon focus)?
- 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
- Weapon focus can reduce a witnesses’ recall for other details of an event
- This is because anxiety creates a physiological arousal in the body which prevents us paying attention to important cues, so recall is worse
What are the limitations of the research on anxiety having a negative effect on recall (weapon focus)?
- One limitation of the study by Johnson and Scott is that it may not have tested anxiety
- The reason participants focused on the weapon may be because they were surprised at what they saw rather than scared
- Kerri 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 (where scissors would be high anxiety, low unusualness)
- Eyewitness accuracy was significantly poorer in the high unusualness conditions (chicken and handgun)
- This suggests that the weapon focus effect is due to unusualness rather than anxiety/threat and therefore tells us nothing specifically about the effects of anxiety on EWT
What are the strengths of anxiety having a negative effect on EWT?
- One strength is evidence supporting the view that anxiety has a negative effect on the accuracy of recall
- The study by Tim Valentine and Jan Mesout (2009, see right) supports the research on 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 clearly disrupted the participants’ ability to recall details about the actor in the London Dungeon’s Labyrinth
- This suggests that a high level of anxiety does have a negative effect on the immediate eyewitness recall of a stressful event
Who conducted the research on anxiety having a positive effect on recall?
John Yuille and Judith Cutshall (1986)
What was the procedure for the research on anxiety having a positive effect on recall?
- John Yuille and Judith Cutshall (1986) conducted a study of an actual shooting in a gun shop in Vancouver, Canada. The shop owner shot a thief dead
- There were 21 witnesses - 13 took part 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 at the time of the incident (on a 7-point scale) and whether they had any emotional problems since the event (e.g. sleeplessness)
What were the findings for the research on anxiety having a positive effect on recall?
- The witnesses were very accurate in their accounts and there was little change in the amount recalled or accuracy after five months - though some details were less accurate, such as recollection of the colour of items and 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)
What was the conclusion for the research on anxiety having a positive effect on recall?
- This suggests that anxiety does not have a detrimental effect on the accuracy of eyewitness memory in a real-world context and may even enhance it
- This is because witnessing a stressful event creates anxiety through physiological arousal within the body, causing the fight or flight response to be triggered, increasing alertness
- This may improve memory for the even as we become more aware of cues in the situation
What are the strengths of anxiety having a positive effect on EWT?
- Another strength is evidence showing that anxiety can have positive effects on the accuracy of recall
- Sven-Åke Christianson and Birgitta Hübinette (1993) interviewed 58 witnesses to actual bank robberies in Sweden. Some of the witnesses were directly involved (e.g. bank workers) and some were indirectly involved (e.g. bystanders)
- The researchers assumed that those directly involved would experience the most anxiety
- It was found that recall was more than 75% accurate 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 enhance it
What are the limitations of anxiety having a positive effect on EWT?
- Christianson and Hübinette interviewed their participants several months after the event (four to 15 months)
- The researchers therefore had no control over what happened to their participants in the intervening time (e.g. post-event discussions)
- The effects of anxiety may have been overwhelmed by these other factors and impossible to assess by the time the participants were interviewed
- Therefore it is possible that a lack of control over confounding variables may be responsible for these findings, invalidating their support
Who invented the inverted-U theory?
Robert Yerkes and John Dodson (1908)
What does the inverted-U theory state?
According to the Yerkes-Dodson Law:
- When we witness a crime/accident we become emotionally and physiologically aroused
- That is, we experience anxiety (emotional) as well as physiological changes in our body (the fight or flight response)
- Lower levels of anxiety/arousal produce lower levels of recall accuracy, and then memory becomes more accurate as the level of anxiety/arousal increases
- However, there is an optimal level of anxiety, which is the point of maximum accuracy
- If a person (or eyewitness) experience any more arousal, then their recall suffers a drastic decline
