Eyewitness Testimony & the Cognitive Interview

Question 1

What is Eyewitness Testimony (EWT)?

Answer 1

The evidence provided in court by a person who witnessed a crime, with a view to identify the perpetrator of the crime

Question 2

Stages of an Eyewitness event transferring to memory

Answer 2

1. Eyewitness encodes details of event in LTM
2. Eyewitness retains information for a period of time
3. Eyewitness retrieves the memory from storage

Question 3

Misleading information

Answer 3

Supplying information that may lead a witness’ memory for a crime to be altered

Question 4

Misleading Information: Leading Questions

Answer 4

Questions which suggest to the witness what the desired answer is and leads them to that desired answer

Question 5

Misleading Information: Post-Event Discussion

Answer 5

A conversation between co-witnesses or an interviewer and an eyewitness after a crime has taken place which may contaminate the witness’ memory for the event

Question 6

Leading Questions: Loftus & Palmer (1974)

Answer 6

• Lab experiment with 150 students
• Watched film of car crash and asked leading question asking them to estimate speed (had a variety of verbs, eg. smashed, hit), those with more aggressive verbs had faster estimates
• Questioned a week later, and asked if they saw broken glass (there was none)
• 16 in ‘smashed’ group said they did, 7 in ‘hit’ group, 6 in control group

Question 7

Post-Event Discussion: Conformity Effect

Answer 7

• Co-witnesses may reach a consensus view of what actually happened
• Occurs due to ‘memory conformity’ - more likely to pick up incorrect ideas because we believe we are wrong and the other is right
• Could occur due to ‘memory contamination’, where the mixing of memories leads to misinformation

Question 8

Post-Event Discussion: Repeat Interviewing

Answer 8

Each time an eyewitness is interviewed there is the possibliity that comments from the interviewer will become incorporated into their recollection of events

Question 9

Anxiety

Answer 9

A feeling of unease, such as worry or fear

Question 10

Arousal

Answer 10

A physiological state in which the heart and breathing rate increase

Question 11

Weapon Focus Effect

Answer 11

Attention spotlight is drawn to dangerous objects, preventing perception of other objects

Question 12

Anxiety decreases EWT accuracy: Johnson & Scott (1976)

Answer 12

• Man ran through ‘waiting room’ carrying a pen covered in grease (low anx. condition) or a knife covered in blood (high anx. condition)
• Participants asked to identify man from set of photographs
• Mean accuracy in low anx. group was 49%, and in the high anx. group it was 33%
• Loftus et al (1987): this was due to weapon focus effect

Question 13

Anxiety increases EWT accuracy: Christianson & Hubinette (1993)

Answer 13

• Questioned 58 real witnesses to bank roberies in Sweden
• Witnesses either high anx. victims (bank teller) or low anx. bystanders (customers)
• All witnesses showed good detail recall (75%<), but those in higher anx. could recall more details

Question 14

Resolving the Conflict: Deffenbacher (1983)

Answer 14

• Reviewed 21 studies on anxiety & EWT, found that 10 had results that linked higher arousal levels with increased EWT accuracy, whilst 11 showed the opposite
• Suggested Yerkes-Dodson Effect (moderate anxiety increases accuracy)

Question 15

Catastrophe Theory

Answer 15

• Some suggest Y-D effect does not happen in extreme anxiety situations - reduces internal validity
• Many participants show rapid decline in recall after peak anxiety is reached

Question 16

The Cognitive Interview

Answer 16

A procedure designed for use in police interviews that involve witnesses - designed to improve EWT accuracy

Question 17

What are the 4 techniques used in cognitive interviews?

Answer 17

• Mental reinstatement of original context
• Report Everything
• Change Order
• Change Perspective

Question 18

Mental Reinstatement of Original Context

Answer 18

• Witness mentally recreates physical and psychological environment of the incident
• Makes memories accessible as recreating mental state can unlock retrieval cues

Question 19

Report Everything

Answer 19

• Witness is encouraged to report every detail, even if it seems insignificant
• Memories are interconnected, so recaling one item may cue others
• If many witnesses reveal small details, the bigger picture can be pieced together

Question 20

Change Order

Answer 20

• Events should be recalled in a different chronological order to the original sequence
• This disrupts effects of expectations and schema on recall

Question 21

Change Perspective

Answer 21

• Witnesses should recall incident from perspective of someone else
• This disrupts the effect of expectations and schema on recall

Question 22

Supporting Evidence of Cognitive Interview: Kohnken et al (1999)

Answer 22

• Meta-analysis of 53 studies found 34% increase in correct information provided in cog. in. compared to other techniques
• However, most studies involved volunteers, which are usually college students in a lab

Question 23

Opposing Evidence for Cognitive Interview: Konhken et al (1999)

Answer 23

• Effectiveness has been in quantity, not quality of information
• Found 61% increase of incorrect info in cog. int. compared with standard interviews
• Police need to treat cog. int. infor with caution as it is not always accurate