Lesson 10: Misleading Information and EWT Flashcards
What is an eye witness testimony?
The evidence supplied to a court by people who have seen a crime, based on their memory of the incident. This evidence can include an identification of the perpetrator or details of the crime. Juries are often heavily influenced by eyewitnesses.
Leading questions
Questions phrased in such a way as to encourage a witness to give a certain answer. The response-bias explanation argues that leading questions do not affect memory, merely the answer the person chooses to give. However, substitution-bias explanation proposes that leading questions distort memories because they contain misleading information.
Loftus and Palmer leading questions study
Showed 45 American students a film of a car crash and then asked them to estimate the speed that the cars were travelling when they crashed. Different verbs were used in the question depending on the condition- contacted, hit, bumped, collided, or smashed.
Findings- pps in the ‘contacted’ condition estimated the speed as 31mph but in the ‘smashed’ condition they estimated as 41mph. A week later, pps were asked if they saw any broken glass, even though there was none in the film. 32% in the ‘smashed’ condition reported seeing glass compared to only 12% in the control condition.
This shows that leading questions significantly impact what people recall and can change a persons memory of an event.
Positive of leading questions study by loftus and palmer
Laboratory study therefore highly controlled, reducing chance of extraneous variables, increasing the validity of results- easier for scientists to replicate to gain same results, meaning study is reliable.
Negatives of leading questions study by loftus and palmer
Questionable ecological validity. The pps watched a video of a car crash- people who witness a real car accident have a stronger emotional connection to the event and may not be as susceptible to leading questions.
Lacks population validity- study consisted of 45 American students. Students are less experienced drivers and may be less competent at estimating speeds. Therefore unable to generalise results to other populations. Older and more experienced may have more accurate judgments and be less susceptible to leading Qs.
Post event discussion
The memory of an event can be contaminated through discussing events with others due to misinformation (memory contamination). Also, a desire for social approval can lead co-witnesses to reach a census view of what happened (memory conformity).
Gabbert et al post event discussion study
Put participants in pairs and got them to watch a different video of the same event so that they each got unique details. In one condition the pairs were encouraged to discuss the event with one another before individually recalling the event. In the other condition they did not discuss what they had seen with one another.
71% of witnesses who had discussed the event went on to mistakenly recall details that they could not have seen themselves, but that they had learned during the discussion with their partner.
Positive of post-event discussion study by gabbert et al
The study has population validity. Two different populations, students and older adults, were compared and there were no significant differences between these two groups. This allows us to conclude that post event discussions affects younger and older adults in a similar way.
Negative of post-event discussion study by gabbert et al
Lacks ecological validity - pps knew they were taking part in an experiment and they therefore are more likely to have paid close attention to the details of the video clip. The results do not reflect real life where witnesses may be exposed to less information.
