Criminal Classic Study - Loftus & Palmer (1974)

Experiment 1

Aim

• To investigate how accurately we remember the details of a complex event like a traffic accident.
• To test their hypothesis that the language used in eye witness testimony can alter memory, specifically the role of leading questions.

Procedure 

• This was a lab experiment using independent measures. Loftus used 45 of her own students who were put in groups of various.
• Each group was shown seven films (in a different order for each group) that each showed a road traffic accident, varying from 5-30 seconds.
• Afterwards, they were asked to fill out a questionnaire asking them to "give an account of the accident you've just seen" and to answer other specific questions. Nine subjects were asked "about how fast were the cars going when they hit each other?" and an equal number of subjects the same question with "smashed", "collided", "bumped" and "contacted" in place of "hit".

Results

• The mean speed estimate was measured and it was found that "smashed" had the highest mean estimate at 40.5 mph and "contacted" had the lowest at 31.8 mph.
• The results suggested that the sort of question given to a witness will impact the response they give.

Conclusions

• The wording of the question affects the estimate of speend; more severe sounding verbs produce higher speed estimates.
• Loftus suggested this may be due to distortion (the verbal label…