Eyewitness Testimony

Question 1

The weapon-focus effect

Answer 1

This is where in violent crimes, arousal may focus the witness on more central details of the attack (eg: weapon) than the more peripheral details (eg: what else was going on and what the perpetrator looked like).

Question 2

YERKES-DODSON LAW (1908)

Answer 2

• The relationship between emotional arousal (anxiety) and performance is an inverted U.
• There is an optimal level of anxiety needed for accurate recall.

Question 3

Christianson & Hubinette 1993

Answer 3

• Questioned real victims of a bank robbery. They found that those who had actually been threatened were more accurate in their recall, compared to those who were onlookers. This continued to be true 15 months later.

Question 4

Deffenbacher et al 2004

Answer 4

• Meta-analysis which found that high levels of stress impacted on the accuracy of EWT.

Question 5

Lotfus and Palmer 1974

Answer 5

• 45 students shown 7 films of traffic incidents
• Students were given questionnaire
• There was one critical question about how fast the cars were going - each with a different verb
• collide, hit, bump, contacted, smashed

Question 6

Johnson & Scott (1976):

Answer 6

• Participants believed it was a lab study
• The low anxiety group heard a casual conversation then a man walking out with a pen and greasy hands
• The high anxiety group heard a heated argument followed by the sound of breaking
  glass then a man walked out with a bloody knife

Question 7

Johnson & Scott (1976) findings and conclusions

Answer 7

• The participants then had to pick out the man from 50 photos
• 49% who saw the man holding a pen could pick him out
• 33% who saw the man holding the bloody knife could pick him out
• Tunnel theory suggests that people have enhanced memory for central events; weapon focus as a result of anxiety can have this effect

Question 8

Yuille & Cutshall (1986):

Answer 8

• Study of an actual shooting in a gun shop in Vancouver
• Shop owner shot their dead
• There were 21 witnesses and 13 took part in the study
• Interviewed 4-5 months after event
• Interviews compared to real police interviews months prior
• Accuracy determined by number of details reported
• They had to rate how stressful it was on 7-point scale and if they had emotional
  damage

Question 9

Yuille & Cutshall (1986) findings and conclusions

Answer 9

• Participants were accurate in their accounts
• Some details were less accurate such as colour of items
• Participants with highest stress levels were most accurate (88% compared to 75% of
  less stressed group)
• This suggests that anxiety does not have detrimental effect on the accuracy of
  eyewitness memory in real world