Eye witness testimony Flashcards
evidence of anxiety impacting eye witness testimony
Yuille and Cutshall
summarise Yuille and Cutshall evidence
Witnesses of a real life accident had remarkable accurate memories of a stressful event involving weapons
-the police interviewed witnesses five months after the crime and compared them to what they’d said at the time .
-Witnesses who were more stressed were 88% compared to 75% who weren’t stressed.- anxiety has an effect
Summarise Loftus experiment
-Two groups of people watched a video of a fast food restaurant
-in one group the customer hands the employee a check and hands him some money.
- in the other group the customer pulls out a gun and employee hands out some money
-39% of no weapon group identified correctly compared to the 11% of people in the weapon group
summarise Christianson and Hubinette
110 witnesses of 22 real life bank robbers were interviewed 4-15 months after the crime. Some had been onlookers of the customers, so their anxiety was low to none
-victims had a 75% accurate in their recall of the robbers, still evident 15 months later
-No difference between rated degree of anxiety and number of details remembered
What is the Yerkes Dodson law?
The Yerkes Dodson law dictates that performance increases with anxiety, but only up to point when levels on anxiety become to high, performance decreases.
What is the inverted u?
Deffen Bacher
-performance increases with anxiety but only to certain point
What is EWT ?
The ability of people to remember the details of events, which they have observed.
What is misleading information?
Incorrect information given to eye witnesses
What was the aim of Loftus and palmer EWT research?
To test their hypothesis that the language used in eye witness testimony can alter memory. Leading questions could distort eye witness testimony accounts and have a confabulating effect
What was the procedure of Loftus and palmer experiment?
45 American were split into 5 groups in a lab experiment
-participants were shown a video of a car crash, after watching the film participants were asked to describe hat happened as if they were eye witnesses - asked how fast were the cars going when they hit, smashed ,bumped or collided
What were the findings of Loftus and palmers experiment
-The estimated sped was affected by the word used
-participants in the ‘smashed’ condition reported the highest speed estimate at 40.8mph and ‘contacted’ was 31.8mph
what is the conclusion of the Loftus and palmer experiment
-Results show that the verb gave an impression of the speed of the car, and this altered the participants perception
-ewt can be biased in terms of how the questions were asked.
What is response bias explanation?
When a person gets a leading question it biases their response without changing memory
What is memory substitution explanation?
- when a person gets a leading question it changes there stored memory
- this has important implications for the questions used in police interviews of eye witnesses.
What was Loftus and palmers second study?
-1974
-participants who originally heard the word smashed were later more likely to report seeing the word glass (there was none) than those who had heard hit. The critical verb altered their memory of the incidence.
What does this experiment show about memory?
Memory can be distorted by leading questions as they can alter the original memory
Response bias explanation
-Wording of a question only affects the way a person decides to respond
-biased towards the verb
Substitution explanation
-Wording of a question alters the memory in the second experiment those who heard smash were more likely to say that they saw broken glass
-verb altered memory
What is post event discussion?
-Occurs when there is more than one witness to an event. Witnesses may discuss what they have seen with other witnesses which can influence accuracy of recall and eye witness testimony
Summarise Gabbert’s study
-investigated the effect of post-event discussion on the accuracy of eye witness testimony.
-60 students
-60 older adults
-participants watched a video of a girl stealing money from a wallet
-control group, co witness group
-watched different perspectives of the same crime
-participants in co witness group discussed the crime
-all participants completed a questionnaire
What are the findings of Gabbert’s experiment?
-71% of the co witness group recalled information they had not actually seen
-60% said girl was guilty despite the fact they had not actually seen the crime
What is source monitoring theory?
-memories are already distorted
-eye witnesses can recall information, but cannot recall where it came from
-source confusion
Conformity theory
-eye witnesses only recall changes because they go along with others
-conform to the majority
Bonder et al
post event discussion can be reduced if participants are warned of the effects
-recall was more accurate when participants were warned that id if hear anything from ither witnesses it could be false
- goes against conformity
Evaluate eye witness testimony -
-lacks ecological validity, artificial stimulus
-cognitive factors may have bigger impact on EWT than emotional factors
-Christian et al interviewed participants 4-15 months after the event
-lacks control over cofounding variables
