Factors Affecting the Accuracy of Eyewitness Testimony Flashcards
What is a leading question?
A queestion that suggests what answer is desired or leads someone to a desired answer
What were the aims and procedures for the Loftus and Palmer speed experiment?
Aims:
* To investigate the accuracy of memory after witnessing a car accident
* To see if leading questions distort the accuracy of EWT
Procedures:
* 45 students were shown 7 films of different car accidents
* After each film, they were given a questionnaire about the accident
* Critical question was “How fast were the cars going when they (verb) each other?”
* Five groups used a different word each: hit, bumped, smashed, collided, contacted
What were the findings for the Loftus and Palmer speed experiment?
- Most was smashed (average 40.8) and least was contacted (average 31.8)
- Leading questions affect the response given by the participants
What was the aims and procedures of the Loftus and Palmer glass investigation?
Aims:
* To see if memory could be altered by post event information
Procedures:
* Participants divided into 3 groups
* Each were shown a film of a car accident lasting 1 minute
* They were then asked questions including one about speed
* Participants returned 1 week later and were asked 10 questions about crash
* Critical question was “Did you see any broken glass?” although there was none
What were the findings of the Loftus and Palmer glass experiment?
- Most was smashed (average 16/50 participants) and least was control (average 6/50)
- Leading questions changed the memory a person had for an event
What are the evluations for the strengths of the Loftus and Palmer experiments?
Headlight evidence:
* Considerable support for research of effects of misleading information
* Loftus and Zanni showed participants film footage of a car accident. Participants were then asked either “Did you see A broken headlight?” or “Did you see THE broken headlight?”
* People who saw a version of the film with no broken headlight were more than twice as likely to say they saw a broken headlight when THE was used, rather than A
* This suggests leading questions affect memory in the same way that Loftus and Palmer suggest. The methodologies are similar and are controlled, precise and easy to replicate
Disney evidence:
* Further considerable support for research into effects of misleading information
* College students who visited Disneyland as children were asked to evaluate advertising material about Disneyland. The material was either about Bugs Bunny, Ariel or neither
* Both were misleading information as Bugs Bunny isn’t Disney and Ariel was not around at the time of their visit. Participants in the Bugs/Ariel condition were more likely than the control group to report seeing them
* This shows how misleading information can create false memories, not only inaccurate memories
Real world applications:
* A strength of investigating EWT is its application to the criminal justice system
* Psychological research has been used to warn the justice system of problems with eyewitness identification
* Recent DNA exoneration cases have confirmed the warnings of eyewitness identification researchers by showering that EWT mistakes were the largest single factor contributing to innocent conviction
* This demonstrates the important role of EWT research in helping to ensure the innocent people are not convicted of crimes they did not commit on the basis of faulty EWT
What are the evaluations for the weaknesses of the Loftus and Palmer studies?
Low emotional arousal:
* A limitation of the studies is that the participants watched film clips
* This is a different experience to witness a real life accident, as clips lack the stress of real life. If a person were to witness a real life accident or crime they would experience emotional arousal
* There is some evidence that such emotions can have an influence on memory, sometimes increasing the accuracy meaning researchers may be too pessimistic about EWT accuracy. Studies about witnesses of armed robberies gave very accurate reports.
* This is a problem as it means the artificial nature of lab experiments ay tell us very little about real life
No real consequences:
* A further problem is that participants may not take the task too seriously
* In the lab it is not crucial if you recall information accurately as there are no real consequences. However, in the real world, eyewitnesses will be far more careful with recall in order to not make errors that lead to severe consequences (could result in an innocent person going to prison)
* Foster et al found that, if participants thought they were watching a real life robbery and thought their responses would influence the trial, their identification would be more accurate
* This is a problem as it means the leading questions seem to have more effect in a lab rather than the real world
What were the aims an procedures of the Gabbert et al study?
Aims:
* To see the impact of post-interview discussion on eyewitness testimonies
Procedures:
* 60 students from university and 60 adults from local community were recruited
* Participants watched a video of a girl stealing money from a wallet
* The participants were either tested individually or in pairs
* The participants in the co-witness group were told that they had watched the same video, however they had in fact seen different perspectives of the same crime and only one person had actually witnessed the theft
* Participants in cowitness group discussed crime altogether
* All participants then completed a questionnaire
What are the findings of the Gabbert et al study?
- 71% of participants mistakenly recalled aspects of the event that they did not see in the video, but picked up during discussion
- 0% mistaken recall in control (individual) group
- 60% said the girl was guilty despite the fact that they had not seen her commit the crime
- Witnesses often go along with each other to win social approval
- Memory conformity
What are the evaluations for the strengths of post-event discussion?
Good reliability
* A strength of the research is consistency of the findings
* Gabbert et al found that participants receiving misinformation after an event were less accurate at recalling the event than control groups. Especially if information came from a social source rather than a non-social source
* This means research in this area has high reliability and allows us to suggest with confidence that EWT is distorted by post-event discussion
Applications of research
* Research into post event discussion has many practical applications
* Police officers should advise witnesses not to discuss the case with co witnesses and will strive to interview the witnesses as soon as possible, to prevent their testimony from being distorted by discussion
* However, in the aftermath, it would be natural for co-witnesses to discuss what they have just seen. Therefore, police officers are advised to take this into consideration when questioning
* This demonstrates the value of the research findings and they can improve accuracy of testimonies
Population validity
* Gabbert’s research is said to have good population validity
* Gabbert et al tested two different populations (university students and older adults) and found little difference between the two conditions
* Therefore her results provide good population validity and allow us to conclude that post event discussion affects younger and older adults in a similar way
What is the evaluation for the weakness of post-event discussion?
Low ecological validity
* The mundane realism of these findings are under scrutiny due to controlled nature of research
* An eye witness who is involved in post event discussion may not act the same way in lab conditions
* There may have been a conformity effect in the research because they knew it was a study, therefore the outcome had no social impact and meant nobody would suffer from their testimony. Therefore, they would be more likely to conform and recall information they hadn’t seen
* The lack of validity in laboratory research suggests we must be cautious when making firm conclusions about the role of post event discussion in real life testimonies
What were the aims and procedures of the Johnson and Scott study?
Aims:
* To see the impact of anxiety upon accuracy of EWT
Procedures:
* Participant was told to wait in reception area
* A receptionist seated nearby excused herself to run an errand
* The experiment used an independent groups design
* Condition 1 overheard a conversation in the laboratory about equipment failure, then the target individual walked out holding a pen, with hands covered in grease
* Condition 2 overheard a heated exchange and the sound of breaking glass and crashing chairs, then the target individual ran out holding a bloodies letter opener
* Both groups were shown 50 photographs and then asked to identify the individual
What were the findings of the Johnson and Scott study?
- No-weapon condition correctly identified the target 49% of the time
- Weapon condition correctly identified the target 33% of the time
- Anxiety supposedly reduces the accuracy of eyewitness testimony
What were the aims and procedures of the Yuille and Cutshall study?
Aims:
* To see the positive impact of anxiety on accuracy of EWT
Procedures:
* Witnesses of a real life shooting were selected
* 21 witnesses were interviewed by investigating police and 13 witnesses chose to take part in the research interview
* Witnesses were asked to rate their stress on a scale of 1-10
* Accuracy was determined by the number of details reported in each account
* Researchers avoided leading questions
What were the findings of the Yuille and Cutshall study?
- Found the witnesses who took part in follow-up interview were accurate in their accounts and little change was seen in the testimonies
- The anxiety had little to no effect on their subsequent memory
- Studies refute the weapon focus effect
What is the evaluation for the strength of EWT anxiety research?
Contradiction between research:
* The Yerkes-Dodson law can be used to explain the contradiction in research findings
* The relationship between emotional arousal and performance represents an inverted ‘U’ in which moderate stress is associated with optimum performance
* It explains why some research shows a negative relationship between anxiety and EWT whilst others show a positive relationship.
* This law can help understand the contradiction in research on EWT anxiety
What are the evaluations for the weaknesses of EWT anxiety research?
Ethical issues:
* Further problems arise with ethical issues
* Deliberately creating anxiety in participants is risky and very unethical as it subjects people to psychological harm, purely for the purposes of research
* Johnson and Scott exposed some participants to a man holding a knife, which could have caused extreme feelings of anxiety. This is an issue as these participants may have left feeling stressed and anxious
* Furthermore, there was deception which would have led to a lack of informed consent
* This matters as it questions the need for such research, especially when researchers can just interview real life witnesses
Weapon focus may not be caused by anxiety:
* A limitation of the weapons focus effect comes from Pickel’s Chicken study who suggested accuracy is reduced by surprise rather than anxiety
* Participants watched a thief enter a hairdressers carrying scissors (HT, LS), handgun (HT, HS), wallet (LT, LS) and a chicken (LT, HS)
* It was found that identification was the least accurate in the high surprise conditions rather than high threat
* This supports the view that the weapons focus effect is related to surprise rather than anxiety
Individual differences:
* There are individual differences in how anxiety affects people. It has been suggested that one key extraneous variable in many studies is emotional sensitivity
* Participants were tested for personality characteristics and were labelled as either neurotic or stable
* It was found that stable participants actually had rising levels of accuracy as stress levels increased, whereas neurotic participants had lower
* This suggests individual differences play an important role in accuracy of EWT
