Eye Witness Testimony

Question 1

Deffenbacher (1983)

Answer 1

Conducted a review of 21 studies, found that moderate levels of anxiety are actually helpful to memory recall, yet once this anxiety becomes too extreme it is associated with a fall in recall

Question 2

Weapon Focus

Answer 2

In violent crimes where the perpetrator carries a weapon, this is often the prime focus of stress, meaning other important details, such as what the criminal looked like, may be forgotten. (tunnel theory)

Question 3

EWT SODA

Answer 3

S - Loftus & Palmer (1974) showed effects of leading questions. Estimate of how fast cars in a video were moving at when the crashed was affected by the verb used in the question - ‘contacted’ was 31.8mph guess, ‘smashed’ was 40.8mph guess. Also more likely to say they saw smashed glass when there was none in ‘smashed’ condition

O - Evidence form real-life crimes doesn’t support leading question effect. Yuille & Cutshall (1986) interviewed witnesses to real-life shooting in Canada. 13 witnesses were reinteriewed 4-5months after the event, and produced aaccurae account of the events despite the introduction of 2 leading questions. Also very anxious at time of event, over 5 on 7-point scale. Thus anxiety and leading questions not much effect on recall

D - Johnson & Scott (1976) shows effect of weapon focus. control group heard a conversation in an adjacent room then man emerged with greasy pen. In experimental condition, they heard and argument and a man with a bloody knife emerged. 49% correctly identified the man from 50 pics, only 33% in experimental condition.

A - Changes in the legal system, can no longer convict form EWT alone due to their unreliability

Question 4

Lab Study Pros

2

Answer 4

Pros
High control over extraneous variables increases validity
Conditions created can be easily replicated, thus reliable

Cons
May lack ecological validity as the nature of the experiment is artificial
Risk of demand characteristics

Question 5

Field Study Eval.

Answer 5

Pros
Detailed qualitative info

Strong ecological validity as it’s a real life scenario

Cons
Generalisation to wider population can be hard as it’s such a unique incident

Difficult to replicate

Question 6

Problems with EWT

3

Answer 6

• Encoding challenges, central executive cant efficiently allocate all information due to information overload
• Stress during the incident affects recall (Mesout & Valentine)
• Schemas may effect EWT