Factors Affecting The Accuracy Of Eyewitness Testimony Flashcards
What are the factors affecting the accuracy of eyewitness testimony
- Misleading Information
- Anxiety
Misleading information
Incorrect information given to an eyewitness usually after the event
Research on leading questions- Loftus and Palmer
- The wording of a question may lead or mislead you to give a certain answer
- Loftus and Palmer
- 45 participants watched film clips of a car accident
- Then they asked the questions about the accident- how fast were the cars going when they hit each other
- 5 groups were given different verbs (hit, contacted, bumped, collided, smashed)
- The mean estimated speed was calculated for each participant group
- Verb contacted estimated 31.8 mph
- Verb smashed estimated 40.5 mph
Why do leading questions affect EWT- Response bias
- 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
- Eg. ‘smashed’ leads people to estimate a higher speed
Why do leading questions affect EWT- Wording of questions
(Loftus and Palmer)
Loftus and Palmer
- Wording of question can change participants memories
- Participants who heard smashed were more likely to report seeing broken glass than those who heard hit
- Verb altered their memory of the incident
Research on post-event discussion- (Gabbert)
- Studied participants in pairs
- Each participant watched a video of the same crime but filmed from different points of view
- Means that each participant can see things in the video that others could not
- Then they discussed what they had seen before individually completing the task
- Found 71% of the participants mistakenly recalled aspects of the event that they did not see in the video but had picked up in the discussion
- Memory conformity
Why does post-event discussion affect EWT- Memory contamination
- Memory contamination- co-witnesses to a crime discuss it with each other their EWT may become altered, this is because they combine information from other witnesses with their own memories
Why does post-event discussion affect EWT- Memory conformity
- Memory conformity- witnesses often go along with each other either to win social approval or because they believe the other witnesses are right and they are wrong, however the actual memory is unchanged
Misleading information evaluation points- Real world Application
STRENGTH
Insights applied to police interviewing and expert witnesses
Misleading information evaluation points- Counterpoint
LIMITATION
Film clips in lab are less stressful than everyday life, no consequences. EWT more reliable
Misleading information evaluation points- Evidence against substitution
STRENGTH
Central details not much affected by misleading information
Misleading information evaluation points- Evidence challenging memory conformity
STRENGTH
Post event information on hair colour blended, supporting contamination
Misleading information evaluation points- Demand characteristics
LIMITATION
Lab environment enables control but answers in lab studies influenced by desire to be helpful
How does anxiety have a negative effect on recall
(Johnson and Scott)
- Participants believed they were taking part in a lab study- seated in waiting room
- Low anxiety group- heard casual conversation then saw a man walk past them carrying a pen with grease on their hands
- High anxiety group- heard heated argument with sound of glass breaking then saw man walk out holding a blood covered knife
- Participants later picked out the man from a set of 50 photos
- 49% who had seen the man carrying the pen were able to identify him
- Participants who had seen the man holding the blood covered knife was 33%
What is weapon focus
Weapon focus (focus on the weapon, reducing a witness’s recall for other details of the event)
What is tunnel theory
Tunnel theory of memory argues that people have enhanced memory for central events
why does anxiety have a negative effect
Anxiety creates physiological arousal in the body which prevents us paying attention to important cues, so recall is worse
How does anxiety have a positive effect on recall
(Yuille and Cutshall)
Yuille and Cutshall
- Study of an actual shooting in a gun shop
21 witnesses- 13 took part in the study
- Interviewed 4-5 months after the incident and these interviews where compared with the original police interviews at the time of the shooting
- Accuracy was determined by the number of details reported in each account
- Also asked how stressed they felt at the time of the incident and whether they has any emotional problems since the event
- The witnesses were very accurate in their accounts- little change
- Some details were less accurate such as age/height estimates etc
- Participants who reported feeling high levels of stress were most accurate
Why does anxiety have a positive effect
Witnessing a stressful event creates anxiety through physiological arousal within the body. The fight or flight response is triggered, increasing alertness. Therefore improving memory for the event as we become more aware of cues in the situation
Explain the contradictory findings of anxiety effect on EWT- Yerkes and Dodson
- Relationship between emotional arousal and performance
- Inverted U theory
Explain the contradictory findings of anxiety effect on EWT- Deffenbacher
- Reviewed 21 studies of EWT
- Used Yerkes-Dodson law to explain findings
- When we witness a crime we become emotionally and physiologically aroused
- Lower levels of anxiety produce lower levels of recall accuracy and then memory becomes more accurate as the level of anxiety increases
- Optimum level of anxiety = Maximum accuracy
Evaluation points on the effects of anxiety on EWT- Unusualness not anxiety
LIMITATION
Poor recall due to unusualness (chicken and handgun), not anxiety (Pickel)
Evaluation points on the effects of anxiety on EWT- Support for negative effects
STRENGTH
London Dungeon- anxiety reduced accurate recall of an individual
Evaluation points on the effects of anxiety on EWT- Support for positive effects
STRENGTH
The most anxious eyewitness at bank robbery had the most accurate recall
Evaluation points on the effects of anxiety on EWT- Problems with the inverted u theory
LIMITATION
Explains contradictory findings but focuses just on physical arousal, ignores cognitive aspects of anxiety
