The effects of misleading information on the accuracy of EWT Flashcards
What is an ‘Eyewitness Testimony’?
Eyewitness testimony is the evidence (i.e. details) provided by a person who witnessed an event e.g. a crime or an accident.
Stages in EWT
Coding of information into LTM
Storage/Retention of information
- Memories may be lost or become distorted during retention.
Retrieval of information
- Accuracy may be affected by the questions asked.
What are leading questions?
A leading question is a question that suggests a certain answer.
Leading questions often activate a particular schema, which in turn may influence individuals to give a desired response.
For example, asking ppts ‘What colour was the man’s hat?’, implies the man was wearing a hat, or ‘Did you see the knife?’, rather than ‘Did you see a knife?’.
What is meant by post-event discussion?
This is where misleading information is added to a memory after the event has occurred.
This can occur when eyewitnesses discuss what they saw and compare their perceptions of the event.
what did Bartlett (1932) argue
Bartlett (1932) argued that memories are ‘reconstructions’ of events, influenced by active schemas.
what are schemas
Schemas are packets of information that determine our expectations.
They are based on previous experiences, existing knowledge, contexts, attitudes and stereotypes.
They make sense of the world around us by ‘filling in the gaps’ in our knowledge.
how can schemas affect reliability
This can affect the reliability of memory because witnesses are reconstructing memories that may be biased by schemas that are activated at the time of recall, which can lead to false memories.
Loftus and Palmer (1974)
An investigation into the effects of leading questions.
(Experiment 1)
Experiment 1: Laboratory experiment; 45 university students watched 7 video clips of road traffic accidents, which they were then asked specific questions about.
Critical question: ‘About how fast were the cars going when they hit/smashed/bumped/collided/contacted (HSBCC)?’
There were therefore 5 conditions; independent groups design.
The verb used was manipulated by the researcher (IV)
The DV was the speed estimate (mph) given by each participant
Loftus and Palmer (1974)
(Experiment 1)
Findings
Verb-
Contacted : 31.8
Hit
Bumped
Collided
Smashed : 40.8
Loftus and Palmer (1974)
(Experiment 2)
Loftus and Palmer asked 150 participants to watch a video of a car crash.
There were three conditions:
50 of the ppts were asked to estimate the speed of the cars when they ‘hit’;
50 ppts were asked to estimate the speed of the cars when they ‘smashed’;
The control group weren’t asked this question at all
They returned one week later, where they continued to question them about the accident and asked them the critical question:
’Did you see any broken glass?’
Loftus and Palmer (1974)
(Experiment 2)
Findings
Smashed = 16 yes
Hit = 7 yes
Control = 6 yes
Loftus and Palmer (1974)
Conclusions
Conclusions: 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.
Loftus and Palmer (1974)
P: The study lacks ecological validity…
E: …because it is a laboratory experiment centred on an artificial task (watching videos) and as such lacks relevance to real-life scenarios. Witnessing real car crashes would have much more of an emotional impact, therefore affecting memory differently.
C: This makes it difficult to generalise the findings beyond the experimental setting.
Misleading Information: Are people’s memories affected by blatantly incorrect information?
Loftus (1979) - participants were exposed to a set of slides depicting the theft of a large, red purse from a handbag, of which 98% correctly remembered in an immediate recall test.
When participants were provided with an account where the purse was stated as being brown, were they able to resist this blatantly incorrect information?
In a second recall test, all but two of the participants resisted this blatantly incorrect information and still correctly recalled that the stolen purse had been red.
This suggests that memory is not easily distorted by blatantly incorrect information, but it may be more easily influenced by subtle and plausible misleading information.
Post-Event Discussion
Post-event discussion is where misleading information is added to a memory after the event has occurred.
This can occur when eyewitnesses discuss what they saw and compare their perceptions of the event.
This can occur due to memory contamination where witnesses combine misinformation with their own memory and which actually changes the memory (source confusion), or due to memory conformity where people change their accounts to go along with others to be liked or because they (other witnesses)think they must be right (in which case their memory is unchanged)
The Conformity Effect
Gabbert et al. (2003)
Gabbert et al. (2003) - Participants watched a video of a girl stealing money from a wallet. The participants were either tested individually (control group) or in pairs (co-witness group). The participants in the co-witness group were told that they had watched the same video, however they had in fact seen different perspectives of the same crime and only one person had actually witnessed the girl stealing. Participants in the co-witness group discussed the crime together. All of the participants then completed a questionnaire, testing their memory of the event.
The Conformity Effect
Gabbert et al. (2003)
Findings
Gabbert et al. found that 71% of the witnesses in the co-witness group recalled information they had not actually seen and 60% said that the girl was guilty, despite the fact they had not seen her commit a crime.
These results highlight the issue of post-event discussion and the powerful effect this can have on the accuracy of eyewitness testimony.
P: Loftus’ research was conducted under highly controlled laboratory conditions.
E: The risk of extraneous variables was therefore reduced.
C: This increases the internal validity of the study and also makes it possible for other researchers to replicate her research to check the reliability of her findings.
P: Loftus’ research has highlighted how unreliable eyewitness accounts can be…
E: …which has been of benefit to the criminal justice system.
C: There is now more awareness of the problems with relying too heavily on eyewitness accounts, especially when there is no other evidence to corroborate the account.
P: The results may be due to demand characteristics, rather than genuine changes in memory as a result of the leading question…
E: …because participants may have given the answer they thought the researchers wanted to hear, as suggested by the verb they heard in the critical questions.
C: This therefore potentially decreases the internal validity of the findings.
P: Loftus’ research raises some important ethical issues.
E: Loftus deliberately misled her ppts, which raises the issue of deception. Furthermore, some studies used potentially distressed stimuli e.g. video clips of a car crash, which raises the issue of psychological harm.
C: This stimuli could be particularly distressing for those who have experienced traumatic car accidents.
