2. Loftus (1974)
• Presented Pp’s with a fictitious
case and asked them to judge the
guilt of a man accused of robbing a
grocers and killing the owner and
his 5-yr. old granddaughter.
• On the evidence presented, 9/50
said the man was guilty
3. What if there was an eye-witness?
• Other Pp’s were presented with the
same case but were told that one of the
shop assistants had testified as an
eye-witness who was sure that the
accused was the man who had
committed the crimes.
• On this evidence, 36/50 judged the
accused to be guilty
4. How reliable is the EWT?
• A third group of Pp’s were presented
with the original evidence and the
assistant’s EWT. However, they were
also told that the defence lawyer had
discredited the assistant. He is short-
sighted and had not been wearing his
glasses when the crime occurred so
couldn’t possibly have seen the
accused’s face.
5. How many students in the third
group do you think judged the
accused to be guilty?
Explain your answer and say
what this tells us about the
importance of EWT.
6. The Results?
• In fact, 34/50 thought he was guilty!
• So, a mistaken witness who couldn’t
possibly have seen the crime does seem
to be better than no witness.
8. Loftus & the role of misleading
information
Elizabeth Loftus (1975) suggested:
Eyewitnesses are
Memory is unreliable because the
reconstructive memory of an event can
be affected by the type of
questioning used
Post-event effect
New information suggested after
an event can be encoded into the
Leading questions
original memory, resulting in the
memory becoming inaccurate
9. Misleading Information
Loftus & Palmer AIM: to investigate the effects of
leading questions on the accuracy of
(1975) an eye-witnesses immediate recall
PROCEDURE: Which verb do
Laboratory Experiment you think
elicited the
45 students / 5 groups (her own students)
highest
Students shown 7 films of different traffic accidents estimated speed?
P’s were given a questionnaire after each
Questionnaire’s included one critical question –
“How fast were the cars going when they hit each other? Why?
One group (control group) were given ‘hit’ the other 4 were given
different verbs: Smashed, Collided, Bumped or Contacted
10. Misleading Information
FINDINGS:
VERB SPEED (mph)
Smashed 40.8
Collided 39.3
Bumped 38.1
Hit 34.0
Contacted 31.8
CONCLUSION:
The form of questioning can have a significant effect on a witnesses
answer.
Leading questions provide post event information which can be
stored and affect the original memory forever, reducing the
accuracy of EWT
11. Misleading Information – A02
Think research
Who were the
methods! participants?
Where was
the research What’s
done? What’s wrong with
good about this?
What’s not this?
so good
about this?