Psychology: Memory - Eyewitness testimony: Misleading information

Loftus and Palmer (1974) Leading questions: Procedure

• 45 students watched a clip of a car accident and asked question about speed

• Critical question: How fast were the cars going when they hit each other

• 5 groups, each group had the verb of the question changed to sound more or less severe: hit, contacted, bumped, collided or smashed

Loftus and Palmer (1974) Leading questions: Findings

• The verb ‘contacted’ produced estimate of 31.8mph, ‘smashed’ mean estimate was 40.5mph

• The leading question biased eyewitness recall of an event, because smashed suggested fasted speed than contacted

Response bias explanation for the effect of leading questions on EWT

Leading questions influence how an eyewitness responds, not what they remember. The wording might bias the answer given without changing the actual memory.

Substitution explanation for the effect of leading questions on EWT

The wording of a question affects the actual memory, interfering with and changing the original info stored by the eyewitness

Gabbert et al. (2003) Post-event discussion: Procedure

• Matched pairs watched a clip of the same crime but for one person the clip had details which there wasn’t for the other pair

• Both pps discussed what they saw before taking a test of recall

Gabbert et al. (2003) Post-event discussion: Findings

• 71% of pps wrongly recalled aspects which wasn’t part of the vid that they saw, but heard in discussion

• A control group had no talk therefore no issues

• Evidence of memory conformity

Memory contamination explanation for the effect of post-event info on EWT

When co-witnesses discuss a crime, they may combine info from others with their own memories, leading to distorted recall

Memory conformity explanation for the effect of post-event info on EWT

Witnesses may agree with others accounts to gain social approval or because they believe others are correct even if their own memories differ

Strength - Real world applications in the criminal justice system

• Consequences of inaccurate EWT are serious. Loftus suggests police officers should be careful in phrasing questions to EW

• Psychologists are sometimes expert witnesses in trials and explain limits of EWT to juries

• Therefore psychologists can improve how the legal system works and protect the innocent from faulty convictions

Limitation - evidence challenges the substitution explanation

• Sutherland and Haye found pps recalled central detailed of an event rather that peripheral ones even when asked misleading questions

• Because attention was on central features and memories were relatively resistant to misleading info

• Therefore the original memory of an event survived and was not distorted which is not predicted by the substitution explanation

Limitation - evidence doesn’t support memory conformity

• Skagerberg and Wright’s pps discussed film clips

• The pps recalled a blend of what they had seen and what they had heard from their co-witnesses rather than one or the other

• Suggests that the memory itself is distorted through contamination by post-event discussion and is not the result of memory conformity