Draft: Factors affecting the accuracy of eyewitness testimony: Misleading information

What is an eyewitness testimony (EWT)?

The ability of people to remember the details of events, such as accidents and crimes, which they themselves have observed

What is accuracy of EWT affected by?

Misleading information (leading questions and post event discussion)

Anxiety

What is misleading information?

Leading questions and post event discussion

What is a leading question?

A question which, because of the way it is phrased, suggests a certain answer

Who studied leading questions?

Loftus and Palmer

What was the procedure of Loftus and Palmer’s study into leading questions?

• 45 students watched film clips of car accidents and were asked questions about the accident

• The critical question (leading) was ‘About how fast were the cars going when they ______ each other?’

• There were 5 groups - each one was asked the critical question with a different verb:

• Smashed, hit, bumped, collided, or contacted

What were the findings of Loftus and Palmer’s study into leading questions?

The mean estimated speed was calculated for each group.

The verb contacted resulted in a mean estimated speed of 31.8 mph

The verb smashed resulted in a mean estimated speed of 40.5mph

What speed did the verb contacted result in?

31.8 mph

What speed did the verb smashed result in?

40.5mph

What was the conclusion of Loftus and Palmer’s study into leading questions?

The leading question biased the eyewitnesses recall of an event.

Why do leading questions affect EWT?

• Response Bias - The wording of the question has no real effect on the participants memories but it just influences how they decide to answer. E.g. when a participant gets a leading question using the word smashed, this encourages them to choose a higher speed estimate

• Substitution Explanation - This suggests that the wording of a leading question changes the participants memory of the film clip. Loftus and Palmer conducted a 2nd experiment to prove this and found that participants who originally heard smashed were later more likely to report seeing broken glass (there was none) that those who heard hit. The critical verb altered their memory of the incident.

What is post event discussion?

This occurs when there is more than one witness to an event. They may discuss what they have seen with co-witnesses or with other people which may affect the accuracy of each witness’s recall of the event.