Eyewitness Testimony - Factors Affecting the Accuracy of Eyewitness Testimony - Research and Evaluation
Loftus and Palmer (1974)
Aim
To assess the extent to which participants estimates of the speed of cars involved in accidents witnessed on video could be influenced by misleading questions
Procedure
Experiment 1 - 45 university students , each shown 7 video clips of car crashes. After each accident participants wrote an account of what they could recall and answered specific questions, the key question being to estimate the speed of the vehicles. there were five conditions, with the verb varying in the key questions .
The words were contacted, hit, bumped, collided, smashed
Findings
Experiment 2 - 150 students viewed a video of a car crash. 50 were asked the key question with the word smashed, 50 were asked the key question with the word hit and a control group of 50 weren't asked at all. A week later they were questioned about their memory again, with the key question being, did you see any broken glass (there wasn't any)
Contacted - 31.8 mph
Hit - 34 mph
Bumped - 38.1 mph
Collided - 39.3
Smashed - 40.8
Participants were twice as likely in the 'smashed' condition to recall the false memory of broken glass
Conclusion
Experiment 1 showed that misleading information in the form of leading questions can affect memory recall of eyewitnesses
Experiment 2 showed that misleading information in the form of post event information can also affect memory recall of eyewitnesses
Both studies suggest that at recall misleading information is reconstructed with material from the original memory
Evaluation
The study is a laboratory experiment centred on an artificial task and such lacks relevance to real life scenarios . Witnessing rela car crashes would have much more of an emotional impact and therefore would affect recall differently
The results may be due to demand characteristics, rather than genuine changes in memory, participants may have just given the answer they thought the researchers wanted, as suggested by which verb they heard in the question
Tomes and Katz (1997) found individuals who identify with others moods, score highly on measures of imagery vividness and have poor recall are more affected by misleading questions, implying personality factors influence EWT
Bekerian and Bowers ( 1983 ) shpwed slides of events leading up to a car crash, finding that participants memories remained intact despite being asked leading questions, which suggests that post event information affects the retrieval of memories rather than their storage
Evaluation
The consequences of inaccurate memories are minimal in research settings compared to real life incidents . Foster et al (1994) showed EWT was more accurate for real life crimes as opposed to simulations
Participants don't expect to be deliberately mislead by researchers: therefore inaccurate recall should perhaps be expected since participants believe the researchers to be telling the truth
Misleading information often affects only unimportant aspects of memory. Memory for important events isn't easily distorted when the information is obviously misleading. Subtle and plausible misleading information is much more influential
Studies of EWT that use potentially distressing stimuli bring ethical concerns of psychological harm. For example , care should be taken not to include participants who may have experienced traumatic car accidents. Many studies of EWT also involve elements of deceit
Whether advertisers should be allowed to use techniques that deliberately try to create positive false memories of products so that people will buy them is debatable, as it could be argued to be a form of lying
