Loftus and Palmer 1974 PDF

Preview

Summary

Download Loftus and Palmer 1974 PDF

Description

Loftus and Palmer (1974)

Aim To investigate the effect of leading questions on the accuracy of eyewitness testimony. Will the use of more severe sounding verbs to describe an accident lead participants to: -

Produce a higher estimate of speed? Be more likely to (incorrectly) recall the presence of broken glass?

Information on Experiment The experiment was a laboratory. The design was independent.

Study 1 Participants -

45 students Five groups of nine

Method -

Participants shown seven clips of traffic accidents Asked to write a short account of what they had seen Asked to complete a questionnaire Critical question was ‘About how fast were the cars going when they ******* each other?’ Five different verbs (one per group) were smashed, hit, collided, bumped and contacted

Independent Variable The change of the verb in the critical question

Dependent Variable The estimate of speed with the verb in the question

Results -

The more severe sounding the verb was, the higher the speed estimate was

Verb used in critical question Smashed Collided Bumped Hit Contacted

Average speed (mph) 40.8 39.3 38.1 34.0 31.8

Data Gathered -

Quantitve data was collect This was the speed of the cars

Conclusions -

-

Interpretations:  The verb distorts actual memory  Response bias (demand characteristics) A second study was conducted to explore these possible interpretations

Study 2 Participants -

150 students Three groups of 50

Method -

Procedure similar to Study 1 but three conditions Group 1 – How fast were the cars going when they smashed into each other? Group 2 – How fast were the cars going when they hit each other? Group 3 – Control so they were not asked to estimate speed

One week later -

All subjects were questioned again Critical question, ‘Did you see any broken glass?’

-

There was no broken glass in the film.

Independent Variable The word in the question

Dependent Variable How many people said that there was broken glass or not

Results Group Smashed Hit Control

-

Number of people (out of 50) saying ‘yes’ to broken glass 16 7 6

The wording of the question affected the participants’ memory of the event Those who had the word ‘smashed’ was twice more likely to recall seeing broken glass

Conclusions -

Study 2 offers more support for the first interpretation – that the information we receive in the question can cause an actual distortion of the memory Loftus and Palmer suggest that there are two types of information that go into making up a memory of a complex event and these are;  The information that we get from perceiving an event  The information that we get after the event...