Eyewitness Testimony

Question 1

What is an eyewitness?

Answer 1

An ‘eyewitness’ is someone who has seen or witnessed a crime, and was present at the time of the incident. They use their memory of the crime to give their testimony or a ‘reconstruction’ of what happened.

Question 2

What is eyewitness testimony?

Answer 2

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

Question 3

How accurate is EWT?

Answer 3

Research over the last 30 years has shown that eyewitness identification is a highly unreliable source of evidence…
1. 72% of convictions overturned by DNA testing involved EWT that was not accurate (The Innocence Project)
2. Wells (1998) studied 40 people who were convicted, then released by conclusive DNA evidence. More than 90% were wrongly convicted by inaccurate eyewitness testimony.
3. Ronald Cotton spent 11 years in prison for 2 rapes he didn’t commit. He was picked out of a line up by two victims who misidentified him. Bobby Poole eventually confessed.

Question 4

How do leading questions affect EWT?

Answer 4

when asked a question the wording of the question may lead or mislead you to give a certain answer, a particular issue in EWT because police questions may ‘direct’ a witness to give a particular answer.

Question 5

Research on leading questions

Answer 5

Loftus and Palmer arranged for 45 participants to watch film clips of car accidents and then asked them questions about the accident. In the critical question (a leading question/misleading information) participants were asked to describe how fast the cars were travelling: ‘About how fast were the cars going when they hit each other?’ There were 5 groups of participants and each group was given a different verb in the critical question. One had ‘hit’, others had ‘contacted’, ‘smashed’, ‘bumped’ and ‘collided’.

The mean estimated speed was calculated for each participant group - contacted estimated 31.8 mph whilst smashed estimated 40.5 mph - this leading question biased the EWT recall of an event

Question 6

Why do leading questions affect EWT?

Answer 6

The response-bias explanation suggests that the wording of the question has no real effect on the participants’ memories, but just influences how they decide to answer. When a participant gets a leading question using the word smashed, this encourages to choose a higher speed estimate.

Loftus and Palmer conducted a second experiment that supported the substitution explanation, which proposes that the wording of a leading question changes the participant’s memory of the clip. This was shown because participants who originally heard smashed were later more likely to report seeing broken glass than those who heard hit. The critical verb altered their memory of the incident.

Question 7

Evaluation leading q - real-world

Answer 7

One strength of research into misleading information is that it has important practical uses in the criminal justice system. The consequences of inaccurate EWT can be very serious. Loftus believes that leading questions can have such distorting effects on memory that police need to be very careful about how they phrase their questions when interviewing eyewitnesses. Psychologists are sometimes asked to act as expert witnesses in court trials and explain the limits of EWT to juries. This shows that psychologists can help to improve the way the legal system works, especially by protecting innocent people from faulty convictions based on unreliable EWT.

Question 8

Evaluation - subsitution

Answer 8

One limitation of the substitution explanation is that EWT is more accurate for some aspects of an event than for others. For example, Sutherland and Hayne showed participants a video clip. When participants were later asked misleading questions, their recall was more accurate for central details of the event than for peripheral ones. Presumably the participants’ attention was focused on central features of the event and these memories were relatively resistant to misleading information. This suggests that the original memories for central details survived and were not distorted, an outcome that is not predicted by the substitution explanation.

Question 9

How does post-event discussion effect EWT?

Answer 9

When witnesses discuss the event with each other (post-event discussion), their EWT may become contaminated. This is because they combine (mis)information from other witnesses with their own memories.

Question 10

Research on post-event discussion

Answer 10

Gabbert et al. had participants watch a video of a crime, but filmed from different points of view. This meant that participants all saw different elements of the event. Participants then discussed what they saw in pairs before completing a test of recall individually.
They found that 71% of participants mistakenly recalled aspects of the event they did not see in the video but had picked up in the discussion. The corresponding figure in a control group, where there was no discussion, was 0%.

Question 11

Why does post-event discussion affect EWT?

Answer 11

o Memory contamination – combining (mis) information from other witnesses with own memories (actual memory is changed).
o Memory conformity – to win social approval or they believe they are wrong and other witness is right (actual memory is unchanged)

Question 12

Evaluation - post-event = memory conformity

Answer 12

One limitation of the memory conformity explanation is evidence that post-event discussion actually alters EWT. Researchers showed their participants film clips. There were two versions, e.g. a mugger’s hair was dark brown in one clip but light brown in the other. Participants discussed the clips in pairs, each having seen different versions. They often did not report what they had seen in the clips or what they had heard from the co-witness, but a ‘blend’ of the two, e.g. medium brown. This suggests that the memory itself is distorted through contamination by misleading post-event discussion, rather than the result of memory conformity.

Question 13

Evaluation - post-event discussion = validity

Answer 13

One limitation is that Gabbert’s research that supports how post-event discussion affects eyewitness testimony is low in validity. There is no emotion/element of surprise watching a video, which is very different to witnessing something in real life and therefore the findings are low in ecological validity as they do not consider how typical human emotions like anxiety can affect eyewitness testimony. However, the study does have high internal validity as it is conducted in a lab setting meaning all extraneous variables are controlled. This suggests that the findings of the study may have limited real-world application, lowering the reliability of it.

Question 14

What is anxiety?

Answer 14

an unpleasant emotional state where we fear that something bad is about to happen. People often become anxious when they are in stressful situations. This anxiety tends to be accompanied with physiological arousal

Question 15

How does anxiety affect recall?

Answer 15

Negative - anxiety creates physiological arousal in the body which prevents us paying attention to important cues, so recall is worse. Research has looked at the effect of the presence of a weapon which creates anxiety and reduces a witness’s recall for other details of the event – the weapon focus effect

Positive - The stress of witnessing a crime creates anxiety and through physiological arousal within the body. This triggers the fight or flight response which increases alertness and improves memory for the event because we become more aware of cues in the situation.

Question 16

Research into weapon focus effect on EWT

Answer 16

Johnson and Scott (1976) conducted an experiment that tested the weapon focus effect. Two groups of participants come into what they thought was a laboratory study of human memory. In actuality they were to take part in a simulated interaction intended to determine whether the presence of a weapon would influence eyewitness memory for an event. Participants in the control condition sat in a waiting room where they overheard an argument between two people, following this a man walked through the waiting area carrying a pen and with grease on his hands. In the weapon, high-anxiety condition participants sat in the same waiting room, but instead they heard a heated argument accompanied by the sound of breaking glass. Following this a man walking through the waiting area holding a knife covered in blood. During a photo line-up, the control participants were more likely to accurately identify the man they saw in the waiting room relative to participants in the weapon condition (49% versus 33% correct identifications). The tunnel theory of memory argues that people have enhanced memory for central events, weapon focus as a result of anxiety can have this effect.

Question 17

Evaluation - negative - not anxiety

Answer 17

One limitation of Johnson and Scott’s study is that it may not have tested anxiety. The reason participants focused on the weapon may be because they were surprised at what they saw rather than scared. Another researcher conducted an experiment using scissors, a handgun, a wallet or a raw chicken as the hand-held items in a hairdressing salon video - scissors would be high anxiety but low unusualness. Eyewitness accuracy was significantly poorer in the high unusualness conditions, the chicken and handgun. This suggests that the weapon focus effect is due to unusualness rather than anxiety/threat and therefore tells us nothing specifically about the effects of anxiety on EWT, lowering the validity of the experiment.

Question 18

Evaluation - negative - support

Answer 18

One strength is evidence supporting the view that anxiety has a negative effect on the accuracy of recall. Researchers carried out a study in the real world setting in the London Dungeon designed to frighten people. Visitors agreed to complete questionnaires at the end of their visit to assess their level of self-reported anxiety. They wore heart monitors to confirm they were experiencing anxiety and were split into two groups: high anxiety and low anxiety. They found that 17% of the high-anxiety participants could correctly identify a scary actor they encountered compared to 75% correct identification by those in the low-anxiety group. This suggests that a high level of anxiety does have a negative effect on the immediate eyewitness recall of a stressful event.

Question 19

Research into positive effects on recall of anxiety

Answer 19

Yuille and Cutshall (1986):

• Conducted a study of a real-life shooting in a gun shop where the shop owner shot a thief dead.
• 13 witnesses agreed to take part in the study.
• Interviews were held 4-5 months after the incident and compared to the original police interviews.
• Accuracy was determined by the number of details reported in each account.
• Witnesses asked to rate how stressed they felt at the time of the incident.

Findings:
* Witnesses gave accurate accounts five months later.
* Participants who reported the highest levels of stress were most accurate (about 88% compared to 75% for the less-stressed group).

This shows that heightened arousal associated with anxiety enhances the accuracy of EWT.

Question 20

evaluation - positive - support

Answer 20

One strength is evidence showing that anxiety can have positive effects on the accuracy of recall. Researchers interviewed 58 witnesses of actual bank robberies in Sweden. Some of the witnesses were directly involved, bank workers, and some were indirectly involved, bystanders. The researchers assumed that those directly involved would experience the most anxiety. It was found that recall was more than 75% accurate across all witnesses. The direct victims, most anxious, were even more accurate. These findings from actual crimes confirm that anxiety does not reduce the accuracy of recall for eyewitnesses and may even enhance it.

Question 21

Evaluation -anxiety- limitation

Answer 21

One limitation is that studies into the effects of anxiety on eyewitness testimony when conducted months later may produce results that lack validity. For example, the Denmark bank study interviewed participants several months after the event. The researchers therefore had no control over what happened to their participants in the intervening time. This means the memory can be distorted through contamination by misleading post-event discussion. The effects of anxiety may have been overwhelmed by these factors and impossible to assess by the time the participants were interviews. Therefore it is possible that a lack of control over confounding variables may be responsible for these findings, invalidating their support.

Question 22

What is the ‘inverted U’?

Answer 22

Deffenbacher reviewed studies of EWT and noted contradictory findings on the effects of anxiety. He used Yerkes-Dodson Law to explain his findings.

If anxiety is low – eyewitness testimony recall will not be accurate as they are not alert or motivated to recall information.

If you have medium level anxiety this is the optimum level of anxiety to induce accurate EWT as flight or fight has been activated to enforce motivation to recall details of crime.

If anxiety is high – recall and accuracy of eyewitness testimony declines as someone is too anxious therefore, they are not able to focus on details of the crime

Question 23

What is an issue with the inverted-U theory?

Answer 23

• may be reductionist - too simplistic
• ignored how anxiety has many elements - cognitive, behavioural, emotional and physical.
• only focuses on physical arousal and assumed this is the only aspect linked to EWT
• but the way we think about the stressful situation, cognitive, may also be important