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Anxiety and EWT

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Victoria Varney

on 31 December 2014

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Transcript of Anxiety and EWT

Marking exercise
Factors influencing the accuracy of EWT
Christianson and Hubinette (1993)
Questioned 58 witnesses of real life bank robberies in Sweden.
Witnesses (bank staff or customers) that had been threatened in some way were more accurate in their recall and remembered more details. This was also true 15 months later.
In real life recall is high even when very anxious.

Deffenbacher (2004)
A meta-analysis was conducted of 18 studies between 1974-1997 and he suggested that EWT performance increases gradually up to extremely high levels of anxiety and then, at a certain point, there is a catastrophic drop in performance.
The Weapon-Focus Effect
This is the evidence that witnesses of a crime (where a weapon is involved) focus more on the weapon than on the peripheral details.
Johnson and Scott (1976)
Johnson and Scott investigated the weapon focus effect. There were two conditions, one with a weapon and one without.

Both conditions were outside a laboratory in a waiting area and participants thought that they were listening to genuine exchanges inside the lab.

In condition 1, there was an amicable discussion about equipment failure, and a man emerged holding a pen with greasy hands.

In condition 2, there was a hostile discussion followed by the sounds of breaking glass, and a man emerged holding a paper knife with bloody hands. THIS IS THE WEAPON FOCUS CONDITION.

The participants were then asked to identify the man from 50 photos. 49% could identify the man in condition 1, compared to 33% in condition 2.

This shows that high anxiety reduces the accuracy of facial recognition. Under high anxiety attention is drawn to the central features of the crime (weapon) and thus there is less recall of details (e.g. the perpetrator's face).
Anxiety and EWT
This graph shows:
high anxiety generally leads to reduced accuracy of EWT.
there are individual differences (adult witnesses were more affected by anxiety than children).
Loftus et al (1987) found by following eye movements that the eyewitness’s eyes are physically drawn towards the weapon and away from the face.

Peters (1988) found that participants attending a routine inoculation were able to identify a researcher easier than a nurse from photographs. This supports the weapon focus effect.
An alternative graph has been suggested to show the relationship between anxiety and EWT.
This is called the Yerkes-Dodson Law.
Mark Scheme
Practice Exam Question
Explain one way in which anxiety can affect the accuracy of eyewitness testimony. (4 marks)
Information provided about the procedure is basic and there is nothing about the findings.

Further information that could have been included would be procedures (interviews 15 months later) and the findings (all victims had better than 75% recall).
Practice Exam-Style Questions
Outline how one factor may influence the accuracy of EWT. (2)

Outline how one research study has investigated the effect of anxiety on EWT. (4)

Danila feels extremely anxious when taking exams and feels that this affects her ability to recall important information.
(A) Explain how anxiety might affect her recall. Refer to psychological research in your answer. (4)
(B) Explain why research into the effects of anxiety on eyewitness recall might be claimed to lack validity. (3)
Full transcript