PYA1: Critical Issue
Eye Witness Testimony
EWT
Eye Witness Testimony
EWT
The statements provided by witnesses of a
crime or situation which help to establish
the facts and often convict criminals.
BUT….
• Is a person’s memory of an event always
accurate?
• Can anything affect it?
• Can we help to improve or restore it?
• Can we rely on it in a court of law?
Reconstructive Memory
Bartlett (1932)
Memory does not work like a
camera!
Memory is an active process.
We weave in elements of existing
knowledge and experience
(schemas)
Reconstructive Memory
We form these elements into a
coherent whole.
This means what we actually
remember may not be an
accurate reproduction of the
original stimulus.
Schemas
A packet of information about a
thing.
A cluster of related facts based
on previous experiences.
Why do we need schemas?
• They help us to understand the world and
situations.
• They help us to fill in gaps.
• They simplify the processing required.
• Look at p32 of Exploring Psychology –
Carmichael et al(1932)
• The word given conjured up a set of
expectations about the object
Look at this picture
Write down a description
of what is happening in
the picture
Factors that affect reconstructive
memory
• 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.
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)
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?
One study by 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.
Star Study: Loftus and Palmer (1974)
Aim: To investigate the accuracy of memory for a car
accident and to see whether leading questions affect
accuracy.
Procedure:
Showed films of traffic accidents to 45 participants, then
answered a series of questions about what they had
seen.
Participants divided into 5 groups – all filled in same
questionnaire apart from on critical question* which was
different for each group relating to estimate of speed
when cars ‘hit’ (smashed into, collided with, bumped into,
contacted) each other.
Mean speed calculated for each group.
* About how fast were the cars going when they ….. each other?
Loftus and Palmer (74)
Read about this classic research on p 33 of
Exploring Psychology
Draw a graph of the results in tables 2.1 and
2.2.
What conclusion can be drawn from this
research?
What does is suggest about the accuracy of
EWT?
Any problems with this piece of research?
Star Study: Loftus and Palmer (1974)
Findings: The mean speed varied significantly
between groups.
‘smashed’ – approx 41mph,
‘collided’ – approx 40mph,
‘bumped’ – approx 38mph, ‘
‘hit’ – approx 34mph,
‘contacted’ – approx 32mph
Conclusion: The wording of a question can affect
the accuracy of the answer.
Star Study: Loftus and Palmer (1974)
Criticisms:
 Loftus has made a huge contribution to our
understanding of EWT and her research is rigorous.
 Participants all students – not a repesentative sample.
 They might have guessed what was expected – demand
characteristics.
 People were expecting to witness a car accident. In
real life an accident is unexpected.
 Real eyewitnesses are likely to be emotionally affected
and know their testimony could have serious
consequences. (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.)
Other research by Loftus et al
• Loftus and Zanni (1975) – Showed 2
groups a film of a car accident. More
participants remembered a non-existent
broken headlight in the group that were
asked – ‘Did you see the broken
headlight?’, rather than ‘Did you see a
broken headlight?’
• A criticism of these types of studies is that
they are artificial.