Accuracy of the Eye-witness Testimony

Question 1

What 2 factors affect the accuracy of the Eye-Witness Testimony?

Answer 1

Misleading information
Anxiety

Question 2

What is the Eye-Witness Testimony (EWT)?

Answer 2

The ability of people to remember the details of events that they themselves have observed

Question 3

What are the 2 types of misleading information?

Answer 3

Leading questions
Post-event discussion

Question 4

What is the main study into leading questions?

Answer 4

Loftus & Palmer (1974)

45 students shown a video of a car accident

Participants asked how fast car was going when they hit each other - verb hit replaced

Contacted = mean estimate of 32mph
Smashed - mean estimate of 40.5mph

Question 5

What are the 2 reason why leading questions affect EWT?

Answer 5

Response bias explanation

Substitution explanation

Question 6

What is the response bias explanation?

Answer 6

Suggests the wording has no real affect on memory but affects how the participants answer

Question 7

What is the substitution explanation?

Answer 7

The wording alters the participant’s memory

Question 8

How is the substitution explanation supported?

Answer 8

Loftus & Palmer (1974) - broken glass
Loftus & Zanni (1975) - headlight

Question 9

What did Loftus and Palmer find which supports the substitution explanation?

Answer 9

Participants who heard smashed were more likely to report that they saw broken glass as suppose the the verb “hit” (no broken glass)

Question 10

What did Loftus & Zanni do (1975)?

Answer 10

7% participants said they saw “a” broken headlight

17% participants said they saw “the” broken headlight

Question 11

How does post-event discussion affect the accuracy of EWT?

Answer 11

Memory contamination

Memory conformity

Question 12

What is memory contamination?

Answer 12

When discussion causes the memories to be altered with information that may not be true

Question 13

What is memory conformity?

Answer 13

When witnesses go along with each other’s points as they want social approval but their memory remains the same

Question 14

What did Gabbert et al (2003) find about post-event discussion?

Answer 14

Participants tested individually or in pairs
The pairs were told they watched the same video when it was different perspectives
71% of participants that were in pairs recalled information they didn’t see (as suppose to 0%)

Question 15

What are the strengths of misleading information?

Answer 15

Good control of variables in lab studies

Studies can be replicated to test reliability

Important applications to real life

Shows that co-witnesses should be prevent from discussing the event

Question 16

How was there good control of variables in the lab studies for misleading information?

Answer 16

Extraneous variables such as weather were removed

Question 17

How can the lab studies for misleading information be replicated to test reliability?

Answer 17

Loftus & Palmer + Loftus & Zanni’s experiments were carried out under the exact same procedures - can conclude the iv itself affect the dv

Question 18

How does misleading information have important application to real life?

Answer 18

Police are careful with how they word questions when interviewing witnesses to avoid substitution

Question 19

How does misleading information show that co-witnesses should be prevented from discussing the event?

Answer 19

Gabbert’s study shows that people change their answers when speaking about their testimony with another witness

Question 20

What did Bodner et al (2009) find?

Answer 20

Can reduce effects of post-event discussion if participants are warned of impact

Question 21

What are the weaknesses of misleading information?

Answer 21

Lab studies lack ecological validity

Yuille & Cutshall (1986) - counter research

Lack of population validity

Question 22

How did the lab studies supporting misleading information lack ecological validity?

Answer 22

Watching video isn’t actually experiencing it
Staged event doesn’t cause anxiety - can affect accuracy
EWT has real consequences in real life
Demand characteristics

Question 23

What did Yuille & Cutshall do?

Answer 23

Performed ecologically valid experiment where they interviewed 13 witnesses of a real crime

Participants asked leading questions which had no effect on recall accuracy

Question 24

How do the lab studies supporting misleading information lack population validity?

Answer 24

Many of the experiments which Loftus did involved students which is not a representative sample so we cannot generalise the findings

Question 25

What did Yerkes & Dodson suggest about anxiety’s affect on EWT?

Answer 25

The relationship is an inverted u, performance will increase with stress only up to a certain point

Question 26

What did Deffenbacher find about anxiety’s affect on EWT?

Answer 26

Reviewed 21 studies on the effects of anxiety on EWT
10 linked higher arousal to increased accuracy
11 linked lower anxiety to lower accuracy

Question 27

What did Loftus & Burns (1982) find about anxiety?

Answer 27

Participants allocated to 1 of 2 conditions

Watch violent film - boy shot in head

Watch non-violent film of a crime

Participants less accurate in the violent short film than the participants who watched the other film

HIGH ANXIETY CAUSES LOW RECALL ACCURACY

Question 28

What is the weapon focus effect?

Answer 28

The anxiety levels of observers increase when a weapon is pulled out, also causing them to fixate on the weapon

Question 29

What did Johnson & Scott (1976) find about the weapon focus effect?

Answer 29

Participants sat outside a lab and heard 1 of 2 conditions
1. Friendly convo with man carrying pen with grease on his hands
2. Argument, smashing glass, overturned furniture and a man emerging with blood-stained paper knife

Witnesses had to identify the man from 50 photos

49% accurate identifying man with the pen
33% accurate identifying the man with the knife

Question 30

What did Stelbay (1992) find about the weapon focus effect?

Answer 30

Performed meta-analysis and found a variety of cases which included the presence of a weapon that signifies reduced the accuracy of identifying the person holding it

Question 31

What 2 studies show positive examples of high anxiety?

Answer 31

Christianson & Hubinette (1993) - bank robbery

Yuille & Cutshall (1986) - armed robbery in Canada

Question 32

What did Christianson & Hubinette’s (1993) study find?

Answer 32

Question 58 real witnesses to a bank robbery
Participants were either victims or bystanders

The victims (more anxious) had better and more accurate recall

Question 33

What did Yuille & Cutshall (1986) find?

Answer 33

Witnesses who had been the most anxious during an armed robbery gave the most accurate account

Question 34

What are the weaknesses of anxiety as a factor affecting EWT?

Answer 34

Weapon-focus effect may not be caused by anxiety - Pickel (1998)

Field studies sometimes lack control

Ethical issues

Yerkes Dodson Law too simplistic

Individual differences

Question 35

How might the weapon focus effect not be caused by anxiety?

Answer 35

Pickel (1998)

Suggested low accuracy may be due to surprise rather than accuracy

He had 4 conditions which had high/low elements of surprise and threat

The conditions with higher surprise caused identification to be less accurate than the high threat conditions

Question 36

How might field studies lack control (anxiety)?

Answer 36

Extraneous variables may have affected the results

People with higher anxiety may have been closer which is why they may have been more accurate than the

Question 37

How are there ethical issues during the studies on anxiety?

Answer 37

Creating anxiety in people is unethical itself

In Johnson & Scott’s study, the participants may have been psychologically harmed when witnessing the bloodied knife and there was deception

Question 38

How is the Yerkes Dodson Law too simplistic?

Answer 38

Anxiety is difficult to define and measure accurately

Anxiety can be due to worry and everyday stresses

Question 39

How do individual differences affect anxiety?

Answer 39

A person’s personality may affect their recall rather than anxiety

Bothwell et al (1987)
Neurotic individuals less accurate with higher stress than stable individuals