45 students shown films of different traffic accidents. Then asked to fill out
a questionnaire with various questions about the accidents, with one crucial question: “About how
fast were the cars going when they ____ each other?” Six groups were given different verbs, varying
in degree.
Experiment 2:
Divided into 3 groups (smashed, hit and a control group that did not have any questions
regarding speed) and shown a car accident lasting one minute. The question, “did you see any broken glass?” was asked,
no broken glass having been in the original film. Participants in the “smashed” group were more likely to
think they saw broken glass, suggesting that misleading post-event information does change the way
information is stored
Misleading information: evaluation
Loftus: stop/yield
One group shown car stopping at junction with a “STOP” sign, while the
other group were shown a “YIELD” (give way) sign. Half of each group were given the question:
“did another car pass the red Datsun while it was at the YIELD/STOP sign?” Participants were then
shown each picture again, varying as to which they were shown. 75% if participants who had
consistent questions picked at the correct slide, compared to 41% who had a misleading question
picked the correct slide
Yuille & Cutshall
Interviewed 13 witnesses of armed robberies 4 months after the incident
and included 2 misleading questions. Despite the questions and delay, witnesses provided accurate
recall, matching their initial detailed reports
Lab Study Criticism
Do not represent real life because (1) people
do not take them as seriously and (2) people
are not emotionally aroused as they would be
in a real experiment
Foster, et al: found that if
participants thought they
were watching a real-life
robbery and thought their
responses would influence
trial, their identification of a
robber was more accurate
Weapon-focus effect
Arousal may focus the witness on
more central details of the attack
(i.e. weapon), rather than the minor
things (i.e. what else was going on).
Johnson & Scott:
Condition 1: participants overheard a discussion, a men
then emerging with pen covered in grease.
Condition 2: participants overheard a more heated
discussion, a man then emerging with a penknife
covered in blood.
When asked to identify the man from 50
photographs, participants in condition 1 were 49%
accurate, compared to 33% in condition 2.
Yerkes-Dodson
Law
Steblay: meta-analysis of
studies concerned with the
weapon-focus effect proved
Loftus' findings