Loftus and Palmer (1974) Flashcards
What was the aim of experiment 1?
Loftus and Palmer investigated the effect that leading questions have on an eyewitnesses’ ability to recall infomation
What was the method and procedure of experiment 1?
Forty five American college students watched seven films
of traffic accidents, ranging from 5 to 30 seconds in duration. The participants filled in a questionnaire giving a general account of what they had seen and answering specific questions about the accident. The participants were asked ‘How fast were the cars going when they ____ each other?’ only the verb was changed
What was the findings of experiment 1?
The verb ‘smashed’ generated higher mean speed estimates (40.8 mph) and contacted generated the lowest (31.8 mph)
What was the conclusion of experiment 1?
Loftus and Palmer concluded that the form of a question - and just changing a single word can markedly and systematically affect a witness’s answer to that question
Loftus and Palmer speculated that their findings could be due to two factors;
-A response-bias: the participant is unsure whether to say
30 mph or 40 mph and the verb used biases the estimate
(i.e. ‘smashed’ causes a bias towards a higher estimate)
-The leading question changes the participant’s memory of
the event- for example, the verb ‘smashed’ causes the
participant to ‘see’ the accident more severe than it
actually was
What was the aim of experiment 2
Loftus and Palmer wanted to investigate whether the leading questions distorted eyewitnesses’ memory of an event
What was the method and procedure of experiment 2?
One hundred and fifty US college students were shown a short film of a multiple car crash. The critical question asked about the speed of the vehicles. One week later the participants returned and, without viewing the film again, answered a series of questions about the accident. The critical question was, ‘Did you see any broken glass?’ which the participants answered yes or no. There was no broken glass in the accident but since broken glass is highly likely to occur in a high-speed accident Loftus and Palmer expected participants in the ‘smashed’ condition to answer ‘yes’ to the question
What were the findings of experiment 2?
The responses to the critical question ‘Did you see any broken glass?’ Those on the ‘smashed’ condition were more than twice as likely as those in the ‘hit’ to say ‘yes’ to the critical question
What was the conclusion of experiment 2?
Loftus and Palmer concluded that the verb used in a leading question has an effect not only on speed estimates but also on information called a week later
What was the internal validity of the experiments?
A laboratory experiment was used in both studies which allowed the experimenters to manipulate the independent variable and objectively measure the dependant variable
What was the external validity of the experiments?
A laboratory experiment is often lacking in ecological validity, making it difficult to generalise to the real world. Also, shock and emotional impact of witnessing a car accident in real life cannot be recreated under laboratory conditions
What are the demand characteristics of the experiments?
Another limitation of a laboratory experiment is that the participants know they are in an experiment. This could lead to demand characteristics- for example, they probably suspected they would be asked about the film clips and may have altered their answers to fit in with what they believed the experimenter was looking for
Explain the ethical issue deception
The participants did not know what the aim of the experiment was or that there were other conditions in this experiment. However, the level of deception in these experiments is both necessary and acceptable
Explain the ethical issue protection from harm
Although Loftus and Palmer did show clips of real car accidents to their participants most of the clips were staged. The participants could have still experienced strong emotional reactions to these clips. For example, it is unknown whether any of the participants have been in a car accident themselves
What are the social implications from the experiments?
The findings of Loftus and Palmer’s study have important implications for our understanding of the testimonies given by eyewitnesses to a crime. The consequences of inaccurate information can be catastrophic. Innocent people may go to jail or even be put to death in some parts of the world, just because inaccurate eyewitness statements have been made. The research by Loftus and Palmer shows, first, our memory is reconstructive and that people may nit be aware of it.
The study shows that even in the absence of misleading information, witnesses can still make errors (six people said yes to broken glass in the control group). The error in recall stems from their schema for road accidents and the expectation that there must be broken glass even if they didn’t actually see any. Therefore, eyewitness testimony must be used with caution
