Factors affecting the accuracy of EWT: Anxiety

• Factors affective EWT: Anxiety

  Anxiety has a negative effect on recall

  Creates physiological arousal in the body which prevents us paying attention to important cues.

  Johnson and Scott (1976) led ppts to believe they were going to take part in a lab study. Low anxiety condition- Heard argument in the next room then man walked in carrying pen w/ grease on his hands. High anxiety condition- argument w/ sound of broken glass, man carrying paper knife w/ blood. Later picked from 50 photos. Low= 49%, high= 33%. Tunnel theory- focus on weapon, as is source of anxiety.
• Factors affecting EWT: Anxiety 2

  Anxiety has a positive effect on recall

  Triggers fight-or-flight response which increases alertness so improves memory.

  Yuille and Cutshall (1986) conducted a study on a real-shooting (owner shot thief dead). 13 witnesses agreed to take part. Interviews held 4-5 months after and compared to original police interviews. Ppts who reported the highest levels of stress on a 7-point scale were more accurate when reporting the number of details in each account- 88% compared to 75% for less stressed group.
• Factors affecting EWT: Anxiety 3

  Explaining the contradictory findings

  In Yerkes-Dodson law, the inverted U theory states that performance will increase with stress but only until a certain point, where it decreases drastically.

  Deffenbacher (1983) applied law to EWT- there is an optimal level of anxiety for maximum recall accuracy.
• Factors affecting EWT: Anxiety- evaluation

  Weapon focus effect may not be relevant as the study on weapon focus by Johnson and Scott may of tested surprise rather than anxiety. Pickel (1998) conducted an experiment using scissors, hand gun, wallet and raw chicken in a hair salon. Accuracy was significantly poorer in high unusualness conditions (hand gun & chicken). Suggests weapon focus is due to unusualness rather than anxiety. So doesn't tell us specifically how anxiety effects EWT.
• Factors affecting EWT: Anxiety- evaluation 2

  Yuille and Cutshall's study lacked control. Extraneous variables such as PEDs may have been responsible for recall accuracy. The effects of anxiety may be overwhelmed by these factors, reducing the value of the research.
• Factors affecting EWT: Anxiety- evaluation

  There are ethical issues. Creating anxiety in ppts can cause psychological harm. Challenges the need for research such as Johnson and Scott, when real-life studies can be used. However, benefits of controlled experiments may outweigh the costs.