2.4 - Eyewitness Testimony Flashcards
Eye witness testimony
When a person who was present at a event recalls what happened
Relies on recall from memory
Can be inaccurate or distorted
Factors that affect accuracy of eye witness testimony
- misleading information
- anxiety
- age of the witness
Loftus & palmer (1974)
Misleading information
Conducted two experiments
Experiment 1 :
- shown a film of multiple car crashes
- asked series of questions eg. How fast do you think the car was going when they got hit
- in different conditions the word hit was replaced with “smashed” or “ contracted “ etc.
Experiment 2 :
- participants split into 3 groups
- 1 group given the word smashed another hit and the 3rd control group wasn’t given any indication of the vehicle’s speed
- 1 week later the participants were asked if they’d seen any broken glass ?
Results of loftus and palmer
Results 1:
- participants that were given the word smashed estimated a higher speed
- participants given the word contracted gave lower speeds
Results 2 :
- even though there was no broken glass
- participants were more likely to say that they’d seen broken glass in the smashed condition than any other
Conclusion of Loftus & Palmer
Leading questions can affect the accuracy of peoples memories of an event
Evaluation points for Loftus & Palmer study
- implications for questions in police interviews
- artificial experiment - watching a video that is not emotionally arousing as a real life event which potentially affects recall
- leading questions give participants Ques about the nature of the experiment
- reduced the validity and reliability of the experiment
Loftus & Zanni looked into leading questions study - aim of study
How altering the wording of a question can produce a leading question that can distort EWT
Loftus & Zanni method
- shown a film of a car crash
- asked “ did you see THE broken headlight” “ did you see A broken headlight”
There was no broken headlight in the film
Loftus & Zanni results
- 17% of those asked about “The” broken headlight claimed they saw one
- 7% of the group asked about “ a” broken headlight
Loftus & Zanni conclusion
Simple use of the word “ THE” is enough to affect the accuracy of peoples memory of an event
Loftus & Zanni evaluation
- lab study which made it possible to control any extraneous variables ✅
- possible to establish cause and effect ✅
- artificial study so thus lacked ecological validity ❌
What else can affect the accuracy of recall ?
Post event discussion
Shaw et al. Method
- paired participants with a confederate
- pairs were shown videos of a staged robbery and were interviewed together afterwards
- participant and confederate alternated who answered the questions first
Shaw et al. Results
- participant responded first = recall was accurate 58% of the time
- confederate answered first and gave accurate answers the recall of the participants was 67%
- if confederate gave inaccurate answers = correct recall for participants fell to 42%
Age of witness Valentine and Coxon Method :
- 3 groups ( children, young adults, elderly ) watched a kidnapping video
- asked a series of leading and non leading questions about what they’ve seen
-
Valentine and Coxon results
- elderly and children gave more incorrect answers to non leading questions
- children were mislead more by leading questions compared to adults and elderly
Valentine and Coxon evaluation
- implications in law when elderly and young children are questioned
- artificial experiment wasn’t as emotionally arousing as s real life situation thus lacks ecological validity
Anxiety
- small increases in anxiety and arousal = increase the accuracy of memory
- high levels = negative effect on accuracy
- violent crimes where anxiety increases the witness may focus on central details eg. Weapon and neglect other peripheral details eg. What the criminal was wearing ?
Loftus - weapon focus in EWT method :
- study with independent groups design participants heard discussion in a nearby room
- 1 condition = a man came out of the room with a pen and grease on his hands
- 2nd condition = the man came out carrying a knife covered in blood
- participants were asked to identify the man from the 50 photographs
Lofus - weapon focus in EWT results
- Participants in Condition 1 were 49% accurate
- 33% of the participants in condition 2 were correct
Loftus - conclusion
When anxious and aroused witness focused on a weapon at the expense of other details
Loftus evaluation - weapon focus in EWT
- study has high ecological validity as the participants weren’t aware that the study was staged
- thus means that there are also ethical considerations as participants could have been very distressed at the sight of the man with the knife
Evidence against : misleading questions and anxiety don’t always affect EWT
- field study by YUILLE and CUTSHALL showed that witnesses of a real incident ( gun shooting ) has remarkably accurate memories of the event
- a thief was shot and killed by police and witnesses were interviewed
- 13 were invited to be re- interviewed 5 months later
- recall was highly accurate even after the time period
- researchers had included two misleading questions but these had no effect on the subjects answers
- study had high ecological validity as it was based on real life event
- the witnesses who experienced the highest levels of stress were also closest to the event - it’s difficult to determine whether proximity or stress contributed to the accuracy of recall
Cognitive interview
A questioning technique used by the police to enhance retrieval of information from the witnesses memory
- important role within the legal system and the serious repercussions when it goes wrong