Loftus and Palmer (1974)

Question 1

Aims?

Answer 1

• To investigate how information provided to a witness after an event will influence their memory of that event
• More specifically, to see if the phrasing of a question about speed would affect the ppts estimation of the speed of cars

Question 2

Briefly describe the procedure of the first part of this classic study

Answer 2

• 45 American students were split into 5 groups
• They were all shown the same 7 clips of a staged traffic accident (5-30 secs)
• Ppts completed a questionnaire with all same questions except for ‘how fast were the cars going when they smashed/collided/bumpbed/hit/contacted each other?’
• The clips were counterbalanced as the order was different for each group

Question 3

Results from first study?

Answer 3

Found that those asked ‘smashed’ estimated the speed of the car to be 9mph faster than those asked ‘contacted’

Question 4

Conclusion from first study?

Answer 4

• The verb used in the critical question influenced the speed estimate
• The more powerful verbs that suggested higher speeds before impact received higher estimates

Question 5

What 2 reasons did Loftus suggest could be the reason for why leading questions affect memory?

Answer 5

1) Distortion - the wording (verbal label) led to ppt cognitively changing memory
2) Response bias - ppt is not sure and therefore adjusts estimate to fit with expectations

Question 6

What were the aims of Loftus’s follow up experiment?

Answer 6

• To investigate the origin of the different speed estimates

- To investigate whether estimates were due to distortions or response bias

Question 7

Sample of second study?

Answer 7

150 students

Question 8

Briefly describe the procedure of the second part of this classic study

Answer 8

• 150 students were split into 3 equal groups
• They were shown a 1 min clip of a multiple car accident
• At the end they were given a questionnaire asking them to describe the accident and then answer 10 questions about it that were asked in a random order
• They were asked the critical question of: “About how fast were the cars going when they hit each other?”
• The verb was changed to smashed or hit, for two conditions, the third were not asked for a speed estimate
• 1 week later the ppts returned and were asked: “Did you see any broken glass?” even though there wasn’t any

Question 9

Results from second study?

Answer 9

Smashed - 16 said YES, 34 said NO

Hit - 7 said YES, 43 said NO

Question 10

Conclusions from second study?

Answer 10

• The smashed condition had the highest amount of people responding yes (16) and lowest amount responding no (34)
• This suggests that people in the smashed condition assumed there would be broken glass if they could not recall any themselves

Question 11

Strength?

Answer 11

P- High reliability
E- 2 lab experiments using a standardised procedure, e.g. all ppts were shown 7 clips of 5-30 seconds each of a staged traffic accident that were taken from the Evergreen Safety Council and Seattle Police
E- Allows for replication to check for consistency in the results

Question 12

Weakness?

Answer 12

P- Low eco validity
E- Lab study so ppts knew they were taking part in the experiment, ppts exposed to videos instead of a real life accident
E- In real-life situations, there would be an element of surprise, so might not be paying attention

Question 13

Weakness?

Answer 13

P- Low generalisability
E- Student sample
E- Not a representative age, driving experience and educational experience, e.g. they may be used to paying attention and getting tested

Question 14

Application?

Answer 14

P- Applicable to real life
E- Can be used when police are questioning witnesses - leading questions can influence the witnesses answers
E- Police should avoid leading questions to get a more accurate recall of events