Loftus and Palmer 1974

Question: How language, mainly asking an individual about an event, can affect the memory of a witness.

Hypothesis: The hypothesis of this experiment was that memory is not an accurate recording of an event and that memories can become distorted by other information which occurs after the event.

Study Type: Laboratory Observation

Ethical Issues/Problems: There weren’t any ethical issues when performing this experiment.

Description: The main focus of this experiment was to observe how information supplied after an event, affects a witness’s memory of the event. In order to do this, E.F. Loftus and J.C. Palmer set up two different experiments. The first one included a group of 45 students from the University of Washington. These students were shown various clips that had to do with safety and traffic accidents. After watching the clips, the students were asked to respond to what they observed. They were also given specific questions and one critical question asking about the vehicles’ speeds in the collision. This question was ‘About how fast were the cars going when they *** each other?’ For each of these conditions, a different word was used in the space, such as crashed, smashed, and collided. After reviewing the answers, Loftus and Palmer concluded that the phrasing of the question created a difference in speed estimate. They could then conclude that the memory of how fast the cars were traveling could have been altered by the verbal label that was used to describe the crash. In the second experiment, they wanted to back up the theory that the speed estimate was affected by the verbal label. This time, 150 students participated and watched a 1 minute clip which contained a 4 second scene of a multiple car accident. 50 participants were then asked 'How fast were the cars going when they hit each other?’ Another group of 50 participants were asked 'How fast were the cars going when they smashed into each other?' The remaining 50 of the participants were not questioned about the speed of the vehicles. After a week later, the participants were asked a critical question asking whether there was broken glass at the scene or not. The results were that a significant amount of people were more likely to remember seeing broken glass when they heard the word ‘smashed.’

Author: Tessa Hockley