8. Accuracy of EWT: Anxiety

What is meant by the negative effect of anxiety on EWT?

High levels of anxiety can reduce the accuracy of eyewitness testimony.

Key study for negative impact of anxiety

Johnson and Scott

Procedure of negative impacts of anxiety

PP were told they are taking part in lab experiment and sat in a waiting room.

In the “low anxiety” cond, a man walked through with greasy hands and holding a pen.

In the “high anxiety” cond, pp overheard an argument, the sound of breaking glass, a man walked out holding a bloody knife covered in blood.

PP were then asked to pick out the man from 50 different photos.

Finding of negative impacts of anxiety

“Low anxiety” 49% of pp correctly identify the man

“High anxiety” 33% of pp correctly identify the man

Conclusion of negative impacts of anxiety

Anxiety decreases accuracy of EWT

What is a weapon focus effect?

Anxiety narrows attention, focuses on the weapon, reducing awareness of key details such as faces

Strengths of negative impacts of anxiety

• Controlled environment

Manipulated the IV such as threatening object, weapon or a non threatening object, while kept the environment, timing and recall procedures standardised. Researcher can isolate the effects of anxiety on memory accuracy, so it’s more likely that difference in recall is due to the preset of threat and increased anxiety, rather than other factors like individual difference or difference in questioning

• Research evidence

  Burns found that pp who watched a violent version of a crime (a boy was shot in the face), pp remember fewer details of the event in comparison to those who watched a non violent version. It cause a high level of anxiety, drawing attention to the most threatening aspect of the event, supporting the idea of attentional narrowing, where anxiety limits attention. Increases internal validity, as supports the idea.

Weaknesses of negative impacts of anxiety

• Demand characteristics

  PP had to sign up for the experiment and were sitting in a waiting room where the event occurred, so they were aware that they were being observed and they behaviour and memory would later be tested. So they could have alter their behaviour accordingly with what they think they are expected to do or purposefully select inaccurate photo to fit in with the study. Reduces internal validity, as it becomes unclear whether reduced EW accuracy is caused by genuine anxiety effects or by pp altering their behaviour to fit in.

• Methodological issue of cause and effect

  Pickels study someone at a hairdresser is being threatened by either scissors, wallet, handgun or raw chicken. They found that accuracy of recall was lower for raw chicken and handgun conditions. Suggesting that recall accuracy may not be due to anxiety, but how unusual the object is. Raw chicken- not threatening, yet recall was still poor, indicating surprise, rather than anxiety. Weakens the conclusion that anxiety causes reduced accuracy, as his findings show that other factors may be responsible, reducing internal validity.

What is meant by the positive effect of anxiety on EWT?

What is meant by the positive effect of anxiety on EWT?

Why can anxiety improve EWT accuracy?

Anxiety can increase alertness and attention, leading to better encoding of important details.

Anxiety can increase alertness and attention, leading to better encoding of important details.

The Yerkes–Dodson law.

The Yerkes–Dodson law.

Performance is best at moderate levels of anxiety, not too low or too high.

Key study supporting positive effects of anxiety

Yuille and Cutshall

Procedure of Yuille and Cutshall

Conducted a real life shooting in a gun shop in Canada. 13 were interviewed 4-5 months after and then the interviews were compared with their original statements given at the time of the shooting. PP were als asked to report how stressed they felt .

Findings of Yuille and Cutshall

PP who had repostprted highest level of stress were the most accurate in their recall of the event (88% accurate)

Conclusion of Yuille and Cutshall

Anxiety can increase the accuracy of EWT

Strengths of positive effects of anxiety

• Research support

58 witnesses were interviewed to real bank robberies in Sweden. Witnesses who were directly involved in the crime ( bank employees who had been threatened) were over 75% accurate in their recall in comparison to witnesses who were indirectly involved. Directly involved- high level of anxiety, which increased alertness, attention. Supports the idea that anxiety can enhance encoding of important details. Increased external validity, real bank robberies, so can be generalised

Weaknesses of positive effects of anxiety

Incomplete explanation

Yerkes-Dodson Law suggests that moderate levels of anxiety can improve recall, while too much or too little can impair it. The theory alone may oversimplify the relationship between anxiety and accuracy of memory, as it doesn’t consider how levels of anxiety influence recall. He provides greater explanatory power for how anxiety can impair accuracy of EWT.