factors affecting the accuracy of eyewitness testimony Flashcards
what is the role of an eyewitness
to give evidence in court that can result in convictions
what did Bartlett argue
memories are not accurate ‘snapshots’ of events carefully preserved in our minds.
how are our memories reconstructive
they are influenced by our personal attitudes and the stereotypes we hold so our recall is not objective
when does it become a problem for EWT
if recall is not objective
what is a schema
packages of information about people and objects around us. we use schemas as mental shortcuts. when we recall a memory it is influenced by schemas, memories change to fit with the individuals pre-existing bias
what do schemas do
they reflect our attitudes and memories and we use schemas to construct our memories
why are schemas a problem for EWT
if memory is reconstructive, then its not accurate. in its reconstruction, it is changed and will produce errors.
what are reconstructive memories
memory is not an accurate recording of events. it is reconstructed in recalling and may produce errors (confabulations)
what do reconstructive memories explain
how misleading information influences memory
what can misleading information appear in the form of
leading questions
what are leading questions
the words used to ask questions can imply a certain response and this influences the memory that someone reports
what are two explanations for why memory is altered
substitution bias
response bias
what is substitution bias
actual memory does change replacing the old memory completely
what is response bias
actual memory doesnt change but there is an emotional pressure that alters your response
how did Loftus and Palmer (1974) investigate the effects of leading questions
they showed traffic accident clips to participants. after watching the clip, they were asked the leading questions
what was the question L&P asked
“how fast were the cars going when they __________ into each other”
what did they keep changing in the leading question
the verb asked
what were the different verbs used
smashed
collided
bumped
hit
contacted
what were the results of the L&P experiment
the more extreme the verb, the faster the estimation of the travellers speed
contacted suggested the slowest speed (31.8mph on average)
smashed suggested the fastest speed
(40.8mph on average)
what were the conclusions of the L&P experiment
misleading information in the form of leading questions can influence the recall of EWT
what did L&P do one week later
in a 2nd study, participants were invited back and completed a follow up questionnaire.
what did L&P ask in the 2nd study
“did you see any broken glass?”
what were the results of L&P’s 2nd study
more than twice as many participants said they had seen broken glass in the ‘smashed’ condition
why were the results of L&P’s 2nd study the way they were
it had been a week since the first part of the study and so its likely the participants may not remember that the word ‘smashed’ or ‘hit’ was originally used - this is subsitution bias
what is post event discussion
contamination of EWT with another witness’s memory reducing accuracy
what usually occurs during PED
witnesses usually discuss what they have seen and we find that their testimony alters to match the accounts of other witnesses
what is memory conformity
witnesses go along with other accounts for social approval
how did Gabbert et al (2003) investigate PED
they showed videos of the same crime to pairs of participants. each member of the pair was shown a different video showing the crime from a separate perspective.
what were the results of G. et al (2003) experiment
if they were allowed to discuss what they had seen with the other witness, when interviewed later alone 71% of participants would include items they hadn’t seen in the video but heard in the discussion.
compared to 0% in pairs who were not allowed to discuss what they had seen
what was G.et al experiment a demonstration of
memory conformity
how did Bodner et al (2009) investigate PED
the experimental setup was similar to Gabbert, particpants were explicitly discouraged from sharing information in their testimony. it was found that these participants shared significantly less information gained from the other witness. this suggests that if warned about the dangers of PED its effects can be reduced
what is another factor affecting EWT
anxiety
what is the definition of anxiety
mental state of arousal that includes feelings of exteme concern and tension. this is often accompanied by physiological changes such as increased heartrate
why does anxiety affect EWT
in many situations that use EWT witnesses are recalling anxious situations like violent crimes.
why do some of the lab based research lack validity
none of the situations participants are exposed to are anxious situations.
why do some psychologists suggest anxiety decreases recall
people are so anxious that they become distracted not paying attention so they can’t accurately recall later
what is the weapon focus effect
the eyewitness is so focused on the gun or knife that they don’t look at the face of the criminal
why do some psychologists suggest anxiety increases recall
the anxiety makes the witness more alert to the situation around them as well as the stronger emotion making a stronger memory and improve memory encoding
what is the Yerks-Dodson Law of Arousal
EWT accuracy increases as anxiety raises as the witness becomes alert. However, at a point, anxiety becomes too high and more stress/distraction results in lower accuracy
explain the Yerks-Dodson Law of Arousal
when anxiety = low, recall = low as the witness isnt paying attention. as anxiety increases, witness becomes more aware and focused so recall improves. at a certain point, the witness is too anxious and stressed so in that panic loses concentration resulting in less accurate EWT
how did Johnson and Scott (1976) investigate the effect of anxiety on EWT
unaware/naive participants sat outside a lab waiting to take part in a study (they didnt know the study had started).
what conversation did the participants hear (J&S)
participants either heard a conversation about equipment failure and a man walking out with greasy hands and a pen or a hostile conversation, breaking glass and furniture being knocked over
what were the participants told to do (J&S)
when asked to identify the man from 50 photographs 49% of participants could identify the man with the pen. only 33% could identify the man with a knife.
what were the results of the experiment (J&S)
results showed anxiety caused by knife resulted in weapon focus and less accurate EWT
how did Peters (1988) investigate the effects of anxiety on EWT
patients at a real healthcare centre were given a real injection by a nurse with a researcher present in the room. patients were able to better recognise the researcher than the nurse. the anxiety was caused by having an injection and there is weapon focus on the syringe
what did Yuille and Cutshall present (1986)
counter evidence against the effects of anxiety on EWT
what was the Yuille and Cutshall experiment
13 witnesses to a real life deadly shooting were interviewed 4 months after the events. researchers found recall to be highly accurate, participants managed to resist leading questions and high levels of stress didn’t seem to impact the accuracy. some of the most accurate recall was from the people who would have been most stressed during the shooting
give additional evaluations on factors affecting the accuracy of EWT (strengths)
- research on limitations of EWT has led to real life applications. led to the development. designed to reduce influence schemas on accuracy of recall
give additional evaluations on factors affecting the accuracy of EWT (weaknesses)
- research in a lab have low validity because of lack of consequences. incorrect EWT in a courtroom when under oath can lead to wrongful convictions.
- lab studies suffer from demand characteristics with participants memories not actually changing but perhaps picking up on the language used and guessing a response that they think the researcher wants to hear (this is a problem especially when looking at leading questions)
- researchers have an ethical duty to protect their participants from harm and to gain informed consent. Research on anxiety breaks both the guidelines and could be considered unethical. even interviewing people about traumatic experiences could lead to additional anxiety
