Factors a ecting the accuracy of eyewitness testimony
Misleading information: leading questions and post event discussion
An eyewitness - someone who sees something rst hand
Studies have shown that eyewitness testimony (EWT) can be distorted by leading questions &
post even discussion
Leading questions:
They point to a certain answer because of how they are phrased.
Making leading questions non leading:
Did you see the broken glass? → What did you see?
Did you see the woman hit the dog? → How did the woman behave?
How drunk was the perpetrator? → What was the perpetrator’s behaviour like?
Many of the early studies of memory demonstrated how memories are not accurate records of
our experiences. We try to t past events into our existing representations of the world
(known as schemas), making the memory more coherent or make more sense to us.
Loftus and Palmer (1974) - Reconstruction of Automobile Destruction
• This Is a study aimed to investigate how leading questions in uences a witness’s memory for
that event.
• Laboratory experiment
• Independent measures design
• 45 American students
• Shown clips of a car crash on a screen
• Given a questionnaire
• One critical ‘leading question’: “How fast were the cars going when they hit each other?”
• Participants then split into 5 separate conditions.
• Each given a di erent leading verb: smashed, contacted, bumped, collided, hit.
Results:
• “Smashed” condition ‘remembered’ the car going at 40.5mph
• “Contacted” condition: 31.8mph
• In a 2nd study, 1 week later - “was there any broken glass?” Smashed condition - Yes
Conclusions:
• Response-bias: wording didn’t actually e ect memory. They didn’t know, they said what they
thought was expected (demand characteristics).
• Substitution explanation: the leading question actually changed the memory.
→Participants who heard the word smashed were more likely to say the had seen
broken glass when there wasn’t any.
Post event discussion:
When witnesses discuss an event afterwards, this can distort their original memory as they
combine other peoples memories with their own, reconstructing/contaminating their own
memory.
Gabbert et al (2203):
• Showed pairs of participants a video of a crime (a woman stealing money from a bag).
ff
ff fi ff fi fl
Misleading information: leading questions and post event discussion
An eyewitness - someone who sees something rst hand
Studies have shown that eyewitness testimony (EWT) can be distorted by leading questions &
post even discussion
Leading questions:
They point to a certain answer because of how they are phrased.
Making leading questions non leading:
Did you see the broken glass? → What did you see?
Did you see the woman hit the dog? → How did the woman behave?
How drunk was the perpetrator? → What was the perpetrator’s behaviour like?
Many of the early studies of memory demonstrated how memories are not accurate records of
our experiences. We try to t past events into our existing representations of the world
(known as schemas), making the memory more coherent or make more sense to us.
Loftus and Palmer (1974) - Reconstruction of Automobile Destruction
• This Is a study aimed to investigate how leading questions in uences a witness’s memory for
that event.
• Laboratory experiment
• Independent measures design
• 45 American students
• Shown clips of a car crash on a screen
• Given a questionnaire
• One critical ‘leading question’: “How fast were the cars going when they hit each other?”
• Participants then split into 5 separate conditions.
• Each given a di erent leading verb: smashed, contacted, bumped, collided, hit.
Results:
• “Smashed” condition ‘remembered’ the car going at 40.5mph
• “Contacted” condition: 31.8mph
• In a 2nd study, 1 week later - “was there any broken glass?” Smashed condition - Yes
Conclusions:
• Response-bias: wording didn’t actually e ect memory. They didn’t know, they said what they
thought was expected (demand characteristics).
• Substitution explanation: the leading question actually changed the memory.
→Participants who heard the word smashed were more likely to say the had seen
broken glass when there wasn’t any.
Post event discussion:
When witnesses discuss an event afterwards, this can distort their original memory as they
combine other peoples memories with their own, reconstructing/contaminating their own
memory.
Gabbert et al (2203):
• Showed pairs of participants a video of a crime (a woman stealing money from a bag).
ff
ff fi ff fi fl
