Eyewitness Testimony - a2 Psychology Lesson updates 13-14
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Transcript Eyewitness Testimony - a2 Psychology Lesson updates 13-14
Eye Witness
Testimony
EWT
Eye Witness Testimony -1
AO1 - outline what is meant by the terms
EWT and Leading questions
A01/2 -Discuss the factors that affect the
accuracy of EWT (leading questions,
anxiety, age of witness)
Evaluate the impact of misleading
information on EWT
Eyewitness Testimony
Reconstructive memory
Schema driven errors
Effect of leading questions
Other factors
Weapon focus
Effects of anxiety/arousal
Age of witness
www.psychlotron.org.uk
Reconstructive Memory
Bartlett (1932)
Memory is not a direct record of what was
witnessed
What is encoded and how it is retrieved
depends on:
Information already stored in memory
How this info is understood, structured and
organised
www.psychlotron.org.uk
Reconstructive Memory
Schemas
Knowledge structures that relate to commonly
encountered objects, situations or people
Enable us to predict events, make sense of
unfamiliar circumstances, organise our own
behaviour
Act as filters to perception & recall
www.psychlotron.org.uk
Computer Information Processing
BANG!
www.psychlotron.org.uk
Can you
wreck a
nice
beach?
Schema Driven Processing
Yes. I can
recognise
speech.
www.psychlotron.org.uk
Can you
wreck a
nice
beach?
Bartlett (1932)
Input
Schema
Output
‘Turf cutter’
Bartlett (1932)
See also Carmichael et al (32)
p 32 Exploring Psychology
www.psychlotron.org.uk
‘Pickaxe’
EWT: Schema Driven Errors
Witnesses to crimes filter information
during acquisition & recall
Their schematic understanding may influence
how info is both stored & retrieved
Distortions may occur without the witness
realising
www.psychlotron.org.uk
Past experiences
Assumptions about
what usually happens
Stereotypes & beliefs
about crime &
criminals
www.psychlotron.org.uk
EWT: Schema Driven Errors
Look at this picture
Write down a description
of what is happening in
the picture
Factors that affect Eye Witness
Testimony
Stereotypes - Allport and Postman (1947)
Participants shown a cartoon of a black and a
white man on a subway train. Most recalled
that the black man had the razor in his hand.
The razor was actually in the white man’s hand.
(stereotype – more prone to violence).
Conclusion: When an actual perceptual fact
doesn’t match our expectations, we trust our
expectation more than the real situation.
We see what we expect to see and this forms
the basis for the memory for an event.
EWT: Leading Questions
Loftus (1970s onwards)
Effect of leading questions on recall
Leading questions introduce new information
Leading info may activate wrong schemas in
witness’ mind
Consequently, witness may recall events
incorrectly
www.psychlotron.org.uk
Factors that affect reconstructive
memory
How
witnesses are interviewed –
leading questions, facial
techniques, tone of voice of
interview may unintentionally
communicate their expectations
(what they want to hear).
Eye Witness Testimony
Elizabeth Loftus (70’s)
Research)
Illustrated the reconstructive
nature of memory.
Star Study: Loftus and Palmer
(1974)
http://www.youtube.com/watch?v=8hwEUaOeuFQ
The role of misleading questions?
In her research Loftus showed that
memories can be affected by the wording
of questions.
A leading question is a question about an
event that is phrased in such a way as to
prompt a particular answer.
Information is provided in the question (i.e.
after the event) which may distort the
accuracy of the memory.
Do people believe EWT’s?
Loftus (1974) shows that people tend
to believe a suspect is guilty if there
is an eyewitness.
So it is very important that
psychologists find out why EWT is
inaccurate and how to improve
accuracy.
Loftus and Palmer (74)
Read about this classic research in your text
book
Draw a graph of the results
What conclusion can be drawn from this
research?
What does is suggest about the accuracy of
EWT?
Any problems with this piece of research?
EWT: Leading Questions
Loftus’ studies using film/video/slides road
accidents
‘How fast were cars going when they hit…’
or ‘…when they smashed…’?
‘Smashed’ led to higher speed estimates
Loftus and Zanni (1975)
‘Did you see a/the broken headlight’?
‘The’ produced more affirmative (incorrect)
responses
www.psychlotron.org.uk
EWT: Leading Questions
Loftus’ research usually lab based:
Restricted samples (students)
Artificial stimuli (slides, videos, not real
events)
Potential for demand characteristics to
influence responses
No legal/moral consequences for inaccurate
answers. (Foster et al (1994) – witnesses
more accurate in recalling memory of a bank
robbery when they were led to believe their
testimony would influence a real trial.)
www.psychlotron.org.uk
What other factors affect Eye
Witness Testimony?
Anxiety
If you were a witness to a crime:
How would you feel?
What other factors affect Eye
Witness Testimony?
Age
of witness
Can we rely on the testimony of
children and older people?
How does anxiety and age of witness
affect EWT? Over to you…..
You will be given one of the above
to research using the text book.
Produce a bullet point summary
to report your findings back to the
other group.
When a weapon is
used to threaten a
victim, their attention
is likely to focus on it
Consequently, their
recall of other
information is likely to
be poor
www.psychlotron.org.uk
Anxiety: Weapon Focus
performance
arousal
Graph to show the YerkesDodson Law that says that
performance is best in
moderately arousing conditions
Memory is most
effective at moderate
arousal levels
If the witness was in
a state of extremely
low or high arousal
then recall may be
poor
www.psychlotron.org.uk
EWT: Arousal Effects
Yuille and Cutshall (86)
Assessed level of arousal and accuracy of
testimonies from 13 witnesses to real robberies
or murders.
Less accurate recall when levels of arousal were
high than low, BUT very high arousal led to
better recall than moderate.
Does not match Yerkes-Dodson Law
Could be explained by how close (proximity)
witnesses were to the crime
Closest are more stressed, but have better view
Freud (1894)
Repression – motivated forgetting
Traumatic memories become inaccessible
(in unconscious) to protect us from being
upset by them.
Conflicting evidence for this theory
See p 31 Exploring Psychology
Age of Witness and EWT
Children
Brennan and Brennan (88)
6-15 year olds failed to understand 1/3 of
questions asked by lawyers.
More correct answers when asked more
simple questions (Carter et al 96)
‘Tags’ – ‘didn’t she’ added at end – led to
more yes answers than when tag not
there (Krackow and Lynn 03)
Age of Witness and EWT
Children –
Children often change answers if question
repeated. (Samuel and Bryant, 84.
Blades and Krahenbuhl, 06)
Memon et al (06) – positive, but not
negative stereotypes affect children’s
judgements about people.
Defendents with more positive stereotype
less likely to considered guilty.
Age of Witness and EWT
Thinking Critically about
psychology p 36
How does Memon et al’s
research findings help to
explain why Ian Huntley
was able to get away with
the crime for so long?
When he was interviewed
Ian Huntley (2003) on TV at the time of the
Soham murders
murder he wasn’t
considered a suspect
Age of Witness and EWT
Older Adults as Witnesses
Assumption by police and society that
Memory fails with age, so less reliable Eye
witnesses.
Backed up by:
(Holliday, ‘05), Brimacombe et al (‘97),
Wright and Holliday (’07)
Age of witness made no difference in
cognitive interviews (next lesson!!)
Plenary
1.
2.
3.
Answer the following questions
What type of experiments were those
carried out by Loftus in the 70’s?
What are the strengths and weaknesses
of her research?
Find examples of ethical issues raised
during EWT research. How could they
be addressed?
Homework
Summarise the work you have covered today as
bullet points of the main points or a mind map.
Include – Definition of leading questions, EWT, weapon focus,
Yerkes-Dodson Law
- The research of Loftus – (1974), Loftus and Zanni and Yuille
and Cutshall (pros and cons, ethics e.t.c)
- the affect of leading questions, age and anxiety on EWT
Finish the Case of Wrongful Conviction activity
What does this task highlight about the impact
of misleading info, age and anxiety on EWT?
Eye Witness Testimony AO1 - Describe the cognitive interview
technique and understand its rationale
A01/2 - Describe and evaluate evidence
that underpins our understanding of EW
AO2 - Discuss the impact of misleading
information on EWT
The Cognitive Interview
In the light of the work of Loftus on the
importance of Leading Questions in the
70’s Police needed to change questioning
techniques.
The Cognitive Interview
Also EWT typically takes place in a
different context to acquisition (scene of
the crime)
Lack of retrieval cues (state and context) can
inhibit recall
Reconstruction of the events (either
imagination or simulation) can lead to
enhanced recall
This is one of the elements of the
Cognitive Interview
The Cognitive Interview
Geiselman et al (1985) identified 4
key principles for the cognitive
interview.
In pairs use p 37 of Exploring Psychology and
p14 of your revision guide to find out what those
4 key principles are, plus the principles of the
Enhanced CI (Fisher et a, ’87)
Each study 4 and report back to your partner.
Fill in the worksheet, use as a revision tool.
The Cognitive Interview
Try it for yourself….
Work in fours – 2 of you will be the
interviewers and the other 2 the witnesses
Use the incident from the video
Either ask direct ’interrogative’ questions
(see sheet)
Or Use a Cognitive interview technique
(see sheet)
Compare the accuracy of the recall.
The Cognitive Interview
Outline the pros and cons of the CI, using
research studies –
Fisher et al (87)
Geiselman (86) –
Geiselman and Fisher (97)
The Cognitive Interview
Pros – lots of studies (in real and lab
situations) have shown that CI produce
more forensically rich information .
Cons – Can be time consuming – some
elements missed out (Thames Valley
Police)
- Insufficient training (Memon et al 94)
Plenary
Think LoP
Create a poster, leaflet, or mind map of what
you have learnt about what factors can affect
Eye Witness Testimony and recommendations
for how best to make EWT testimonies as
accurate as possible.
Think about your audience. Select the most
important points. Have a balanced view.