Lecture 7 Eyewitness Testimony Flashcards
What is one example by Brigham and Bothwell (1983) that find that eyewitness testimony is inaccurate ?
They gave ps details of various person identification experiments and asked them to estimate the accuracy of identification. It was found the ps overestimated the accuracy of correctly identifying people.
What four things do jurors base their opinion of eyewitnesses being accurate on?
Witness attributes and style (confidence and attractiveness)
Juror beliefs and preconceptions (think witness is correct 70% of time)
Witnessing conditions (trauma, time lapsed)
Questioning factors (asking things that are hard to remember)
How much variance does perceived confident account for in jurors judgements of witness accuracy?
50%
Correlation of r=.71
What did Bothwell et al (1987) find was the actual correlation between eyewitness confidence and accuracy?
Through a meta analysis of 35 studies they found that the actual relationship between confidence and accuracy was .2519. This was still a significant relationship but was no where near the .71 relationship exhibited by jurors perceptions.
How did Bothwell et al(1987) findings support the optimatily hypothesis?
They found that the longer they viewed the target face initially, the larger the relationship between confidence and accuracy was. This supported the optimatily hypothesis which states that longer viewing durations result in people ending up more justifiably confident
What did Sporer et al(1995) find in relation to the confidence/accuracy relationship when it came to identification ?
If the suspect was identified the correlation increased to .4. However when the suspect was not identified this correlation decreased to .1.
Where is Brewer and Wells (2006) calibration technique for confidence and accuracy most effective?
At the level of police investigation
What is the misinformation effect?
Memories can be planted very easily in people by supplying misinformation about an event they witnessed.
Describe Lofus et al (1978) study which demonstrates that people incorporate misinformation in their memories.
Had ps watch a slide
Show on a car crash at a junction. Half ps saw a yield sign and the other half saw a stop sign. Ps answered qs about the sequence some of which contained misinformation. Found that the people unwittingly incorporated this information into their memories
What is Zaragoza and McCloskey (1989) theory about the misinformation effect?
They suggest that the misinformation effect is due to biases at test. For example if ps can not remember a component of an event (ie like a hammer being used on a scene) and then receive a written summary of the event that indicates that a screwdriver was used then ps will assume the text information was correct and say a screwdriver was on scene. So the Original memory is not overwritten.
Explain the study by Loftus and Palmer (1974) which demonstrates that false memories can be generated without misinformation.
Presented car crashes to ps and got ps to estimate the speed at which the car was travelling. Half the ps were asked how fast the cars were going when they hit each other and the other half were asked how fast the cars were going when they smashed into each other. Those in the smashed group rated the cars as travelling faster than the hit group. Also the smash group recalled glass being apparent on the ground despite no aforementioning of This
Why do people find hypnosis appealing to use? Why are psychologists hestitant to use it?
Hypnosis is appealing to police officers and detectives becuase of the antedoctal evidence like the Chowchilla kipnapping case. However not much lab research has found hypnosis to be effective.
What does hypnosis increase?
Hypnosis increased suggestibility so people under hypnosis are more prone to correctly identify things that happened but to also recall a greater number of false memories.
Describe the study by Krafa and Penrod (1985) that suggests that context reinstatement can help improve recall of memories.
Krafa and Penrod (1985) had a customer (experimentor) go into a store, purchase some things with a travellers cheque and produce 2 forms of ID to a shop assistant. Then another experiment posed as a law intern came in either 2 or 24 hours later and asked the shop assistant if they’d seen the first experimenter come in. He showed the sales assistant 6 photos of what could potentially be the first
Experimenter (half the time was not). The second experimenter tried to reinstate the context for the SA by showing them a form of non photo ID in half the conditions. Reinstating the context by showing the ID improve memory recall significantly without impacting false negatives.
Who developed the cognitive interview and why?
Fisher and Geiselman (1985) developed the cognitive interview as standard police interviews were characterised by frequent interruptions and was prone to suggestability,
