Transcript Eyewitness Testimony

Memory
Watch this clip and answer the
following questions

http://www.youtube.com/watch?v=Nfz6e
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Questions
1.
2.
3.
4.
5.
How many parked cars did you overtake
before the roundabout?
What coloured top was the person
wearing who was talking into the
passenger side?
What was the registration no. of the white
transit van?
How many people were waiting to cross at
the first set of traffic lights?
What colour was the car that over took
you?
Share your answers
Are they all the same?
 Was the pedestrian male or female?
Can you be sure?
 Did the wording of the questions
influence your answers?

Eyewitness Testimony
Important aspect of criminal trials.
 Often very influential.
 Juries can decide based on eyewitness
testimony alone.

Reliable? Factors affecting?
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How accurate do you think you would be in
describing what you witnessed about the
crash?
What factors might influence your statement?
Would being in a police station influence you?
Would the police officers have any effect on
you, say in their manner or in their questioning
technique, even in the language they used?
Would your impressions about police through
television influence you?
Factors affecting testimony:

Anxiety / Stress

Reconstructive Memory

Weapon Focus

Leading Questions (Loftus and Palmer,
1974)
Anxiety/stress
Clifford and Scott (1978) found that people
who saw a film of a violent attack remembered
fewer of the 40 items of information about the
event than a control group who saw a less
stressful version. As witnessing a real crime
is probably more stressful than taking part in
an experiment, memory accuracy may well be
even more affected in real life.
 However, Yuille and Cutshall (1986) found that
witnesses of a gun shooting had remarkable
memory. Even after 5 months and despite
leading questions.

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Chinese Whispers
Reconstructive Memory
Bartlett, 1932 – recall subject to our
perception based on our culture, norms
and experience.
 We fit memories into our understanding.
This means memories can be distorted
or unreliable.
 'War of the Ghosts', Bartlett (1932)

Weapon Focus
As a witness you focus on the weapon
making all other details secondary.
 Loftus, 1987
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Selective attention. Do you remember
the clip with the gorilla?
Loftus and Palmer, 1974
Aim – to test if leading questions can
distort eyewitness accounts.
 M&P – Asked ppts (45 American
students) to estimate the speed of
vehicles after watching a clip of a car
accident. A task ppl are generally poor
at. The IV was the verb used in the
question eg smashes, collided,
contacted etc.

Results
Conclusions
A week later ppts were asked if they saw any
glass at the scene. Despite there being none ppts
in the ‘smashed’ condition were much more likely
to say yes.
 This suggests that memories are open to
distortion by language and that confabulation can
occur (addition of false details to an existing
memory).
 How might you use this knowledge if you are:

a) A police officer
b) A lawyer?
Loftus and Zanni, 1975
Did you see the broken headlight?
VS
 Did you see a broken headlight?
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Ppts asked ‘the’ were twice as likely to
answer yes.
Evaluation
Lacks ecological validity.
 Consequences?
 Closed questions.

For you to research:
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Effect of individual differences on EWT:
 Age
 Occupation

This work has led to the development of
cognitive interview technique. Research
more about this technique.