Loftus and Palmer conducted two experiments to investigate how leading questions can influence eyewitness testimony of traffic accidents. In Experiment 1, participants who were asked how fast cars were "smashed" together estimated the highest speeds, showing more severe verbs led to increased speed estimates. Experiment 2 found participants exposed to the verb "smashed" were more likely to incorrectly report broken glass that was not present. The experiments demonstrated eyewitness memories can be altered by the phrasing of post-event questions.

1. Loftus and Palmer: Reconstruction
of Automobile Destruction

2. Why was the experiment conducted?
• A lot of court cases rely on eyewitness
testimonies, but it has been questioned how
reliable they are.
• There have been many studies that have shown
humans do not recall complex situations
accurately.
• Variables such as time, emotional distress and
distractions have all been proven to effect
reliable recollections of the event.

3. • Loftus and Palmer wanted to investigate how
accurately eye witnesses can recall information
on traffic accidents. For example, providing
information like how fast the vehicles were
traveling and how much damage was caused.
• They conducted two experiments to investigate
the influence of leading questions and also
how time between the event and questioning
effects recall.

4. Experiment One
• 45 students were shown clips of car accidents.
• They were asked to answer questions on what
they had seen. Embedded within the questions
there was the critical question “how fast were the
cars going when they…. each other?” which is
what the researchers were most interested in.
• The participants were split into five groups of
nine and each group was allocated a different verb
within the critical question.
• The verbs were: contacted, hit, bumped, collided
and smashed.

5. Results of Experiment One
Verb Mean Speed (MPH)
Smashed 40.8
Collided 39.3
Bumped 38.1
Hit 34.0
Contacted 31.8

6. • This table shows that the more severe the verb
used in the critical question, the higher the
estimated speed was.
• There are two explanations for this:
1. Response bias- if a participant could not choose
between two speeds, and had a harsher verb such
as “smashed,” they are more likely to select the
higher speed.
2. Reconstructed memory- a harsh verb may cause
the witness to recall the crash as being worse then
it was. Consequently, details are altered.

7. Experiment Two
• 150 students watched a film of a multiple car accident.
• Participants were then asked to complete a questionnaire
about the clip. 50 subjects were asked about the speed
using the verb “smashed,” 50 were in the “hit” group and
50 were not asked about the speed.
• A week later the participants were asked to return and
researchers asked them the critical question “did you see
any broken glass?” In reality there was no broken glass.
• It was predicted that more participants who were part of
the “smashed” group would answer yes than the groups
with the verb “hit” and the control group.

8. Results for Experiment Two
Response Smashed Hit Control
Yes 16 7 6
No 34 43 44

9. • This table shows that more participants are likely
to say “yes” in response to the critical question if
they were asked about the speed using the verb
“smashed” than the verb “hit”. The control group
who were not asked about the speed of the cars
had the least amount of “yes” responses.
• It is worth noting that most participants did not
succumb to leading questions and reported that
they did not see any broken glass.

10. Discussion
• This experiment proves what was already believed, that
a way a question is phrased has great influence on the
answer.
• They found that there are two kinds of information that
goes into a person’s memory during a complex
occurrence.
1. Information gained at the original event.
2. External information supplied after the event.
• A combination of these two factors usually merge
together to form a reconstructed memory.
• For this reason, Loftus and Palmer concluded that eye-witness
testimonies can often be unreliable.

11. Strengths
• Laboratory experiment with clearly defined variables
• Gathered quantitative data
• Experimental validity
• 99.5% significance in their findings in Experiment 1
• Acknowledge faults in their own work which was
considered in the conclusion and analysis
• Two experiments
• Provided further evidence for something that was
already known, implying their results are accurate
• Supporting studies
• Practical applications

12. Limitations
• Low ecological validity
• Low population validity and generalisability
• Some of the procedure was not standardised
• Researcher effects
• Films were not shown for long
• The speed estimates may have been purely due to
response bias
• Flashbulb memory
• Contradicting studies
• Merely confirmed what was already known