Factors Affecting the Accuracy of Eyewitness Testimony: Anxiety (AQA AS Psychology): Revision Note

Anxiety

• Anxiety is an emotion that brings on feelings of tension, worry and physical changes such as raised blood pressure

• Stressful events such as witnessing a crime can trigger anxiety

• Anxiety can affect the accuracy of eyewitness testimony (EWT)

• Research has, however, also shown that recall may actually be better in the presence of high anxiety

Negative effects of anxiety on accuracy

• Anxiety may have negative effects on recall and the accuracy of EWT due to the weapon focus effect (WFE)

• WFE tends to happen during the commission of a crime in which a weapon is used

  • The eyewitness may fixate on the weapon due to fear or the fight-or-flight response etc.

  • Due to this intense focus on the weapon, the person wielding it is not really noticed (the eyewitness does not take in their height, hair colour etc.)

  • Thus, recall of the details of the perpetrator is virtually non-existent

• Johnson & Scott (1976) researched the weapon focus effect

• Procedure:

  • Participants were told they were taking part in a lab study and were asked to sit down in a waiting area

  • Participants were split into a low-anxiety group or a high-anxiety group (the two conditions of the independent variable)

  • While the participants were in the waiting area they witnessed one of the following:

    • The low-anxiety group overheard a casual conversation from a room and saw a man walk out with a pen and grease on his hands

    • The high-anxiety group overheard an argument from the room and saw a man walk out with a knife and blood on his hands

  • Participants were asked to identify the man from a set of photographs

• Findings:

  • The low-anxiety group correctly identified the man with a mean accuracy of 49%

  • Accuracy dropped to 33% in the high-anxiety group

  • The researchers concluded that anxiety focuses attention on the weapon and away from other details of the event

Positive effects of anxiety on accuracy

• Anxiety may have a positive effect on the recall of events during a stressful situation

• This positive effect may be due to an increase in the hormone adrenaline which triggers the 'fight, flight or freeze' response which results in a state of high alertness

• Research carried out by Yuille & Cutshall (1986) investigated whether this may improve memory of events

• Procedure:

  1. Witnesses of a real-life crime shooting were asked to take part in the study (13 witnesses agreed)

  2. Participants were interviewed four to five months following the shooting; the interviews were compared to police interviews

  3. Accuracy was measured by the number of matching details in each interview

  4. Participants were also asked to rate their stress levels at the time of the incident (using a seven-point scale) and related issues, such as insomnia

• Findings:

  • The witness's recall was accurate as events recalled four to five months later matched original police reports

  • Witnesses who reported high-stress at the time of the incident had the most accurate recall with 88% accuracy

  • Low-stress witnesses had less accurate recall with 75% accuracy

  • The findings stress that anxiety does not have a negative effect on the recall of events or the accuracy of EWT, in fact it may enhance the accuracy of recall

Explanation of contradictory findings

• Contradictory findings have been found in studies of EWT

• Yerkes & Dodson (1908) proposed that there is a relationship between arousal (emotion state) and performance

• This is called Yerkes-Dodson Law (also known as the inverted-U theory)and can be used to explain the contradictory findings when related to the accuracy of EWT:

  • When a crime is witnessed, a person becomes emotionally (anxiety) and physiologically (adrenaline release) aroused

  • Low levels of arousal (anxiety) are associated with low levels of performance (recall and accuracy of EWT)

  • As arousal increases performance increases up to an optimum

  • After this point, as arousal continues, performance begins to decrease

Evaluation

Strengths

• Studies support the idea that anxiety leads to less accurate recall:

  • Valentine & Mesout (2009) found that participants' recall of actors in the London Dungeons was less accurate with high-anxiety compared to low-anxiety

  • This study used an objective measure of heart rate to measure anxiety and so has high validity

• Studies support the idea that anxiety leads to higher accuracy of EWT:

  • Christianson & Hubinette (1993) found higher recall in witnesses to a real-life bank robbery

  • Victims of the robbery (high anxiety) had better recall of the details of the robbery compared to bystanders (low anxiety)

  • This suggests that anxiety improves the accuracy of EWT and supports the study of Yuille & Cutshall

Limitations

• The Yerkes-Dodson Law does not take into account all the factors that contribute to anxiety, such as cognition, emotional state and physical health which would all affect the accuracy of EWT

  • This suggests that the Yerkes-Dodson Law may be too simple

• It is argued that Johnson and Scott did not test anxiety but instead fear or surprise

  • Other research has found that EWT is less accurate when unusual objects are involved (such as chickens) as well as weapons

  • This suggests that the weapon focus effect is due to surprise rather than anxiety

• Yuille & Cutshall, and Christianson & Hubinette used a real-life context and real-life crime as part of their investigations

  • This observation invalidates their findings as there is a lack of control over confounding variables which can influence recall of the crime and accuracy of EWT