Lesson 10 - Eyewitness Testimony Flashcards
What is eyewitness testimony
Evidence supplied to a court by people who have seen a crime based on their memory of the incident.
This evidence can include identification of the perpetrator or details of the crimes.
Juries are often heavily influenced by eyewitnesses.
Leading Questions
Questions that are phrased in such a way to encourage witnesses to give a certain answer.
The response-bias explanations argues that leading questions do not affect memory.
Substitution bias explanation proposes that leading questions distort memories as they contain misleading information.
Leading Questions Procedures
Loftus and Palmer (1974)
45 American students saw a film of a car crash and then asked them to estimate the speed that the cars were travelling when crashed. However different verbs were used in the question depending on the condition; contacted, hit, bumped, collided and smashed.
Leading Questions Findings (Speed)
Loftus and Palmer (1974)
Contacted = 31mph Smashed = 41mph
Leading Questions Finding (Broken glass)
Loftus and Palmer (1974)
Participants then asked if they saw any broken glass a week later
32% = broken glass in smashed
12% = broken glass in control condition
Shows leading questions have a significant impact on what people recall and can change a person’s entire memory of an event
Evaluation of Leading Questions - Lab experiment
Highly controlled reducing chance of extraneous variables increasing validity
Easy to replicate = reliable
Evaluation of Leading Questions - Ecological Validity
Participants watched a video of a car crash
People who witness a real car accident have a stronger emotionally connection to event, may not be susceptible to leading questions
Low ecological validity
Evaluation of Leading Questions - Population Validity
45 American students
Students less experienced drivers to less competent at estimating speeds
Unable to generalise results to other populations
Older and more experienced drivers more accurate in judgment of speeds => less susceptible to leading questions
Post Event Discussion
Memory of an event can be contaminated through discussing events with co-witnesses due to misinformation (memory contamination)
Desire for social approval lead co-witnesses to reach a consensus view of what happened (memory conformity)
Post Event Discussion - Procedure
Gabbert et al. (2003)
Participants in pair and watched a different video of same events => unique details of events for each
One condition pairs encouraged to discuss events before recall
Other condition pairs prohibited to discuses events before recall
Post Event Discussion - Findings
Gabbert et al. (2003)
71% of witnesses who discussed with pair went onto mistakenly recall details that they could not have seen themselves but that they had learned during discussion with partner
Evaluation of Post-Event Discussion - Population Validity
Two different populations - students and older adults
Compared and no significant differences between the two groups
Post event discussion affects younger and older adults in a similar way
Good population validity (sample)
Evaluation of Post-Event Discussion - Ecological Validity
Participants knew they were taking part in an experiment => more likely to have paid close attention to details of video
Do not reflect real life where witnesses are exposed to less information
Lacks ecological validity
