Factors Affecting Eyewitness Testimony: Anxiety

Question 1

Anxiety has a negative effect on recall

Answer 1

Anxiety creates physiological arousal in the body which prevents us paying attention to important cues, so recall is worse. One approach to studying anxiety and EWT has been to look at the effect of weapons (which create anxiety) on accuracy of recall of the witness.

Procedure
Johnson & Scott (1976) did research on this. They led participants to believe they were going to take part in a lab study. While seated in a waiting room participants heard an argument in the next room. In the ‘low-anxiety’ condition a man then walked through the waiting area, carrying a pen with grease on his hands. Other participants overheard the same heated argument, but this time accompanied by the sound of breaking glass. A man walked out of the room, holding a paper knife that was covered in blood. This was the ‘high-anxiety‘ condition.

Findings
The participants later picked out the man from a set of 50 photos; 49% of the participants 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 a blood-covered knife was just 33%. The tunnel theory of memory argues that a witness’s attention narrows to focus on a weapon, because it’s a source of anxiety.

Question 2

Anxiety has a positive effect on recall

Answer 2

The stress of witnessing a crime or accident creates anxiety through physiological arousal within the body. The fight-or-flight response is triggered which increases our alertness and improves our memory for the event because we become more aware of cues in the situation.

Procedure
Yuille & Cutshall (1986) conducted a study of a real-life shooting a gun shop in Vancouver, Canada - the shop owner shot a thief dead. There were 21 witnesses - 13 agreed to take part in the study. The interviews were held 4-5 months after the incident and these were compared with the original police interviews made 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, using a seven-point scale, and were asked if they had any emotional problems since the event, such as sleeplessness.

Findings
The witnesses were very accurate in their accounts and there was little change in the amount or accuracy after 5 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).

Question 3

Explaining the contradictory findings

Answer 3

According to Yerkes & Dodson (1908) the relationship between emotional arousal and performance looks like an ‘inverted U’.
Deffenbacher (1983) applied the Yerkes-Dodson law to EWT. Lower levels of anxiety produce lower levels of recall accuracy. But memory becomes more accurate as the level of anxiety experienced increases, just as you would expect. However, there comes a point where the optimal level of anxiety is reached. This is the point of maximum accuracy. If an eyewitness experiences any more stress than this, then their recall of the events suffers a drastic decline.

Question 4

Evaluation of the effects of anxiety on EWT (weapon focus effect may not be relevant, field studies sometimes lack control, ethical issues)

Answer 4

• Johnson & Scott on the weapon focus may test surprise rather than anxiety. The reason participants focus on the weapon may be because they are surprised at what they see rather than because they’re scared. Pickel (1998) conducted an experiment using scissors, a handgun, a wallet or a raw chicken as the handheld items in hairdressing salon video (where scissors would be low 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.
• Researchers usually interview real-life eyewitnesses sometime after the event. All sorts of things will have happened to the participants in the meantime that the researchers have no control over – discussions with other people about the event, accounts they may have read/seen in the media, the effects of being interviewed by the police, and so on (i.e. post event discussions). This is a limitation of field research because it is possible that these EVs may be responsible for the accuracy of recall.
  The effects of anxiety may be overwhelmed by these other factors, and impossible to assess by the time the participants are interviewed.
• Creating anxiety in participants is very risky. It is potentially unethical because it may subject people to psychological harm purely for the purposes of research. This is why real-life studies are so beneficial – psychologists interview people who have already witnessed a real-life event, so there’s no need to create it.
  This issue doesn’t challenge the findings from studies such as Johnson & Scott but it does question the need for such research. One reason is to compare findings with the less controlled field studies – and the benefits of this research may outweigh the issues.