Classic research : The cognitive approach - loftus and palmer Flashcards
What is an eyewitness testimony?
- an eyewitness testimony is the use of eyewitness to give evidence in court concerning the identity of someone who has committed a crime
What did loftus and palmer want to find out?
The reconstruction of automobile destruction: an example of the interaction between language and memory
Procedures
45 american students were split into 5 groups with. 9 participants in each one.
- they were shown the same 7 short video clips of car accidents
- all participants filled in a short questionnaire that included filler questions and the critical question about how fast cars were going when they -blank- each other
- the five verbs were hit, smashed, collided, bumped and contacted
Findings
- a speed estimate was calculated for each group
- it managed to show that the verb used in the question influenced the speed estimate given by the participant
- when the verb smashed was used, participants estimated that the cars were travelling at a higher speed than when another verb was used
Conclusions
- the effect of leading questions is not due to response bias bur is due to memory being altered
- leading questions can actually alter a persons memory of an event
- leading questions cause memory to become reconstructed
Experiment 2 and its aim
- to see if the leading question just biased the responses given to the questions or whether the participants memory had actually been altered as a result of the leading question
Experiment 2 procedures
150 american university students were split into groups of 50
- were shown a short film that showed multi-vehicle car accident
-were asked questions including a critical question
- group 1 was asked how fast were three cars going when they smashed into each other
- group 2 was asked how fast were the cars going when they hit each other
group 3 was a control group so was not asked about the speed
- a week later all particpants returned and were asked further questions
- the critical question was ‘did you see any broken glass’
- there was no broken glass
Experiment 2 findings
- showed that the leading question depending on the word can influence the participants memory
- with the word smashed 16/50 people said they saw broken glass
- with the word hit 7/50 people said they saw broken glass
- with the control group 6/50 people saw broken glass
Methodological issues
- both experiment 1 and 2 are said to lack ecological validity due to the fact that it does not provide insights into how people behave in the real world so it is not generalisable
- in real life situations there would be an element of surprise which may lead to a person not paying attention to detail
-could both lack internal validity
- participants knew what they were taking part in, which could lead to demand characteristics potentially affecting their speed estimates
- HOWEVER were given a lot of questions so they would not figure out the aim
- could both be reliable as they show the participants the same videos and all given particular words, same experience, consistent results
-cannot be generalised so could lack population validity, all of them are students so cannot be generalised beyond that
Ethical issues
Deception
- decieved them as they did not tell them the true aim of the study
- loftus and palmer could justify this as they may have wanted to have more validity within the study and knowing the aim could ruin that
Consequence of decieving them raised the issue of having informed consent
Ability to withdraw
- participants may have felt they could not withdraw because they were all students so may have felt they had to take part
Avoidance of causing harm
- dealt with this by not showing them a real car crash as this may have been distressing to the participants
-this research helped us to understand the accuracy of eyewitness testimonies
