Loftus and Palmer

• To investigate the effects of language on memory
• To see whether memory distortion truly occurs
• To see whether changing the leading questions effects memory distortion

• 45 students shown clips of traffic accidents
• After were split into 5 groups and asked the critical question --- 'How fast were the cars going when they _____ into each other?'.
• Verbs were: Hit, smashed, collided, bumped, contacted.

IV: The critical verb

DV: The speed estimate

Results: Mean estimates

1. Smashed (group 1) - 40.8
2. Collided (group 2) - 39.3
3. Bumped (group 3)- 38.1
4. Hit (group 4)- 34.0
5. Contacted (group 5)- 31.8

- Smashed group were the fastest rated verb.

• Response had biased factors, manipulating words may be lead to demand characteristics
• Participants memory may  be distorted by the leading question

To further validate this experiment, they used concurrent validity. 

• 150 participants watched a short film that showed a multicar crash
• Participants were then split into 3 groups of 50

1. 'How fast were the cars going when they hit each other?'
2. 'How fast were the cars going when they smashed each other?'
3. Asked no question. (control group)

• A week later, subjects were asked 'Did you see any broken glass?' There wasn't any.

Did you see any broken Glass? :

Yes - smashed- 16 Hit-6 Control- 6

No- smashed- 34 Hit-43 Control- 44

• Results show verb used in original question influences whether participants thought whether they saw broken glass or not.

The second experiment did alter people's memory.

Loftus suggested 2 kinds of information go into the memory:

1. Person's own subjective perception at the time of the event
2. information recieved after the event via leading questions or other opinions

They Become intergrated to make a whole memory.

Strengths:

• Labortary experiment- lots of control
• High reliability- easily repeated

Weaknesses:

• Low ecological Validity
• Participants knew they were taking part
• Demand characteristics- as they were students to experimentor

Sample representative?:

1. Students usually young- said memory is better when younger
2. students are used to taking on information all the time and being tested
3. Students may be susceptible to demand characteristics
4. Students may not drive

Quantitative data:

Good - allows us to compare easily

Bad- Doesn't have back up to explain answer

Improvement - Ask how conficent they were with their answers or take them to a real crash site - increases ecological validity.

Useful? :

• Leading questions can effect memory
• Avoiding leading questions
• Make sure court cases are relied on more than just one eye witness testimonies.