Loftus and Palmer 1974 Leading Questions

Background

Memory involves interpreting what is seen or heard, recording bits of it then reconstructing these bits into memories when required

This infers recall can be distorted or biased by certain features of the situation such as wording of questions

This study focuses on the effects of leading questions

AIM - to investigate how information supplied after an event (e.g. leading questions) can influence a witness' memory for that event

Research method (Exp 1)

Sample (Exp1)

Lab experiment

Independent measures design

IV - wording of critical question in questionnaire, "about how fast were the cars going when they hit/smashed/collided/bumped/contacted each other?"

DV - estimated speed given by participant

Research method (Exp 2)

Lab experiment

Independent measures

One group asked - "about how fast were they going when they smashed into each other?"
Second group asked - "about how fast were the cars going when they hit each other?"
Third group not asked about speed

Week later all participants completed another questionnaire with critical question "did you see any broken glass?"

IV - wording of question in questionnaire

DV - Yes/No to broken glass

45 students divided into 5 groups

5 groups of 9 students

Sample (Exp 2)

150 students divided into 3 groups

3 groups of 50 students

Procedure (Exp 1)

All participants shown same 7 clips of different traffic accidents

after each clip participant was given a questionnaire where they had to describe the accident then answer a series of questions

There was one critical question "about how fast were the cars going when they smashed/collided/contacted/bumped/hit each other?"

Each group was given a different verb

Procedure (Exp 2)

All participants shown a one minute film which contained a four second car crash

They were given a questionnaire which asked them to describe the accident then answer some questions - the critical question was about speed

One group was aksed "about how fast were the cars going when they smashed into each other?"
Another group was asked "About how fast were the cars going when they hit each other?"
A third control group did not have a question about vehicle speed

One week later without seeing the film again the participants completed another questionnaire the critical question was "did you see any broken glass? Yes/No" (there was none)

Key findings (Exp 1)

Smashed 40.5
Collided 39.3
Bumped 38.1
Hit 34.0
Contacted 31.8

The film of the crash at 20mph was estimated to be 37.7
The crash at 30mph was estimated to be 36.2
Crashes at 40mph were estimated to be 39.7 and 36.1

Key findings (Exp 2)

Yes - 16 in smashed, 7 in hit and 6 in control
No - 34 in smashed, 43 in hit and 44 in control

Majority of participants correctly recalled not seeing any broken glass

Conclusions

The verb used in a question influences a participants response

People are not very good at judging vehicle speed

Misleading post event information can distort an individuals memory