Lesson 10- eyewitness testimony Flashcards
eyewitness testimony
the evidence supplied to a court by people who have seen a crime based on their memory of the incident, evidence can include identification of perpetrator or details of the crime, juries are often heavily influenced by eyewitness
leading questions
questions that are phrased in such a way as to encourage a witness to give a certain answer
response-bias explanation argues that leading questions do not affect memory, merely the answer a person chooses to give
substitution-bias explanation proposes that leading questions distort the memories because they contain misleading info
leading questions study
Procedure- Loftus and Palmer 1974 showed 45 American students a film of a car crash and then asked them to estimate the speed that the cars were travelling at when they crashed, however different verbs were used in the question depending on condition- contacted, hit, bumped, collided, smashed
Findings- participants in ‘contacted’ estimated 31mph but in ‘smashed’ estimated 41 mph, a week later participants were asked if they saw any broken glass even though there was none in the film, 32% in ‘smashed’ reported they did compared to 12% in control, shows leading questions can change persons recall and memory of event
leading questions evaluation
-lab experiment, highly controlled, reduces chances of extraneous variables, increasing validity, easy to replicate making it reliable
-questionable ecological validity, watched video of car crash, people who witness real car accident, who have stronger emotional attachment to event may not be as susceptible to leading questions
-lacks population validity, study consisted of students-less experienced drivers may be less competent at estimating speeds, unable to generalise findings, older more experiences drivers may be more accurate in speed judgement and less susceptible to leading questions
post-event discussion
memory of an event can be contaminated through discussing events with others due to misinformation-memory contamination
a desire for social approval can lead co-witnesses to reach a consensus view of what happened- memory conformity
post-event discussion study
Procedure- Gabbert et al 2003 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 they were encouraged to discuss the event with each other before individually recalling, in the other they did not discuss what they had seen with one another
Findings- 71% of witnesses who discussed the event went on to mistakenly recall details that they could not have seen themselves but had instead learned during discussion with their partners
post event discussion evaluation
-has population validity, two different populations students and adults were compared and there were no significant differences between them, affects younger and older adults in a similar way
-lacks ecological validity, participants knew they were taking part in an experiment therefore were more likely to have paid close attention to the details of the video clip, results do not reflect real life where witnesses may be exposed to less information
