4.1.2 - eye witness testimony Flashcards
Why is EWT significant
- Important for juries when making decisions
- In 75% of cases, where individuals found to be wrongfully convicted by DNA evidence, the original eye witness testimony which led to the conviction was inaccurate
- research helps further our understanding and has many practical applications and has influenced how courts conduct witness statements and the basis of convictions.
How does the schema influence memory
Schemas are internal representations of the world and do not always accurately represent real life situations
- they can generalise situations leading to inaccurate recall due to pre-set perspectives of the world
Who researched the effect of schemas on ewt
Bartlett (1932)
What did Bartlett propose
- memories are not accurate snapshots of events, but
Are reconstructions - these reconstructions are influenced by active schemas which are not l ways realistic
- schemas affect the reliability of ewt , witnesses aren’t just recalling facts as they happened, they are reconstructing memories.
What investigation did Bartlett carry out to support his view
War of the ghosts
· Bartlett (1932) - when Western cultural participants were told this
story, it didn’t make sense from their cultural viewpoint.
· upon recall, memory of the story was distorted to fit a
Western cultural viewpoint
· Demonstrates how memory can be affected by schemas.
Ways in which misleading info cause in accuracy of ewt
- leading questions ( questions that suggest an answer )
- post event discussion ( discussion between co-witnesses after an event )
Study about misleading info through leading questions
Lotus and Palmer - used language to distort the ppts memory of a situation
Loftus and Palmer - method
- 45 ppts were shown short video clips of a road accident
- all ppts were asked: “about how fast were the cars going when they ……. each other”
- each group was given a different verb to fill the blank.
- the IV was the verb used which were smashed, contacted, collided, bumped or hit
Loftus and palmer - findings
- The estimated speed was affected by the verb used. - The verbs implied information about the speed, which systematically affected the participants’ memory of the accident.
- “smashed” made ppts believe the cars were travelling faster than “contacted” which led ppts to believe that speeds were low
Loftus and palmer - conclusion
- ewt can be biased by the way questions are asked
- two explanations:
1) response bias factors: the misleading info influenced the answer a person ave but didn’t actually lead to false memory
2) the memory representation is altered: the critical verb changed a persons perception of the situation and therefore changed the way in which it is stored in the memory.
Loftus and palmer A03: lab study
Limitation
- not realistic setting: decreases ecological validity
- does it involve flashbulb memories as emotions aren’t heightened
- in real life ppts will not be told to pay attention to a specific event, there is an element of surprise
Loftus and palmer A03: generalisability
Limitation
- all ppts were students, who are not experienced drivers therefore less able to accurately judge speed compared to older people
- all the same age, not generalisable to the whole population
Loftus and palmer A03: real life application
- police questioning witnesses have specific rules avoiding leading questions dues to the effect that they have been suggested to have on memory
Who carried out research on post event discussion
Gabbert (2003)
Gabbert - method
· ppts watched a video of a crime, filmed from different viewpoints.
· so, each participant could see elements of the event that others could not
· In one group ppts, then discussed what they had seen before comparing recall
· In the other group, there was no discussion between ppts
Gabbert - findings & conclusion
- 71% of participants mistakenly recalled aspects of the event they did not see, but picked up in discussion.
-> CONCLUSION:
·witnesses often go along with each other to win social approval or because they believe the others may be right and they may be wrong
-> this is called MEMORY CONFOMITY
Misleading info A03: individual differences
-> A number of studies (eg. schater et al, 1991) have found that compared to younger
subjects, elderly people have difficulty remembering the source of their information,
therefore they are more prone to the effect of misleading into.
-> shows that Identification is an important factor when assessing the
reliability of CNT.
Misleading info A03: real world application
Strength
- research is important to ensure that people are not wrongfully convicted of crimes due to inaccurate ewt
What are the two ways in which anxiety effects ewt
- high anxiety leads to inaccurate recall
- high anxiety has positive effects in recall
Anxiety having negative effects on recall explanation
anxiety leads to increased arousal in the body which can stop us from paying
attention to important cres (such as an attackers face) and therefore recall is
Worse.
What is the weapon focus effect ( anxiety worsening recall)
- If the crime is violent, then high anxiety and levels of arousal may focus
attention on the central details of the attack.
eg: the weapon used instead of the perpetrator’s face
How did Johnson and Scott investigate the weapon focus effect and anxiety worsening recall
ppts In a waiting room overheard discussion in the room next door.
condition 1:
- A man emerges holding an ink stained pen (low anxiety).
- 79% of ppts accurated Identified the man.
Condition 2:
- A man emerges holding a blood-stained knife (high anxiety).
- Only 36%. of ppts identify merges man correctly.
not
Johnson and Scott conclusion
- when feeling anxious, central details of the event were not remembered therefore it is suggested that attention was shifted onto the weapon instead
Anxiety having a positive effect on recall explanation
The stress of witnessing a crime or accident creates anxiety. The fight or
flight response is triggered which increases our alertness and therefore will
improve our memory for the event because we are more aware of cues in
the situation.
Yuille and cutshall method to investigate anxiety positively effecting recall
· A group of as customers in a gun shop in vancouver witnessed the owner of the shop shoot and kill a thief. They all gave statements to the police
· 13 of the original witnesses were interviewed months later by Yuille & cutshall.
- The original statements were compared with the interviews for accuracy and specific details
- ppts were then asked to rate how anxious they were feeling on a scale
Yuille and Cutshall findings
The group of people that reported high stress and anxiety levels recalled the event most accurately
What is the Hermes Dodson law
INVERTED U HYPOTHESIS
- accounts for these contradictory findings that anxiety can both hinder and enhance recall
- · This states that when arousal is concerned
their is an optimum level at which performance
will be best, but below or above which will
be worse.
Anxiety A03: not measuring anxiety
limitation
- Yuille and cutshalk measured stress levels, not explicitly anxiety
- decreases the internal and external validity
- the stress scale is also subjective and social desirability bias may have occurred
Anxiety A03: individual differences
Limitation
- one key extraneous variable in many studies of anxiety is emotional sensitivity.
- Bothwell et al (1987):
· ppts were tested for personality characteristics and were labelled as either ‘neurotic’ (get anxious quickly) or ‘stable ‘(less emotionally sensitive
· He found that stable’ ppts showed increase in accuracy as stress levels rose
·so can be concluded that anxiety levels can both and
accuracy of recall depending on the emotional sensitivity of person.
Anxiety A03: real life application
increased ecological validity of theories by interviewing Hurricane Andrew victims.
- He defined amount of anxiety as level of destruction to home experienced & he found that there was a link between level of recall, and amount of anxiety experienced
-> strengthens increased anxiety = increased recall theories.
