factors affecting eye witness testimony Flashcards
what is meant by ‘eye witness testimony’?
evidence supplied by people who witnessed a specific event/crime, relying only on their memory
what was the devlin committee?
a uk committee which looked at criminal cases to draw conclusions on EWT being used to identify suspects
what did the devlin committee find?
a number of cases where innocent individuals were wrongly convicted due to EWT
- e.g Laszio Virag was misidentified by 8 witnesses
why is it important to study the factors affecting EWT?
EWT misidentification is the greatest contributing factor to wrongful convictions (70%)
describe the supporting evidence from Ronald Cotton and Jennifer Thompson
- Jennifer was sexually assaulted
- Cotton was wrongfully convicted of rape and burglary in January 1985, sentenced to life
- evidence used was a flashlight used at scene matched one in his home, and rubber on his shoes
- DNA did not match, released in June 1995
what is post event information?
information that arrives after the event that may affect the witness’ memory by distorting it
how can post event information distort a witness’ memory?
- leading questions or schemas from other people
- information remembered can be changed due to confabulation/rationalisation
- information remembered can be changed through leading questions that may suggest something being there when a witness does not remember it so they will assume they forgot
what is a strength of post event information as a factor effecting EWT reliability (PEE)?
- supporting evidence
a strength of post event info as a factor affecting EWT reliability is supporting evidence from Loftus and Palmer. this is because they found that when asking ppts how fast a car was going, ppts were more likely to estimate higher speeds with “smashed” as opposed to “contacted.” therefore, this shows that using a leading question will suggest to the witness something is different than what they remembered and so they will assume they forgot or got it wrong leading to a false conclusion.
what is a weakness of post event information as a factor effecting EWT reliability (PEE)?
- opposing evidence
a weakness of post event information as a factor affecting EWT reliability is opposing evidence from Yuille and Cutshall. this is because they found that when interviewing witnesses 5 months after the crime using leading questions they still recalled events accurately. additionally, when interviewers used 2 misleading questions, including one about a broken headlight, 10/13 ppts said there was no broken headlight. therefore, this suggests that any new information that they are exposed to does not have an impact on a witness’ memory.
what is a weakness of post event info as a factor affecting EWT reliability (PEEIA)?
- L & P criticism
a weakness of post event info as a factor affecting EWT reliability is that research lacks ecological validity. this is because EWT is often assessed in controlled, artificial conditions. for example, in Loftus and Palmer’s 1994 study, they asked ppts to watch a video of a collision. therefore, this lacks mundane realism as it doesn’t reflect how ppts would behave if the collision happened in real life. additionally, lab/field studies have high control over extraneous variables. this is a weakness because real cases involve variables which would affect a witness’ memory. therefore, this reduces the validity of the research.
what is a strength of post event info as a factor affecting EWT (PEE)?
- application
a strength of post event info as a factor affecting EWT reliability is the applications. for example, it suggests that when gathering EWT accounts the police should avoid leading questions and exposing the witness to new info. therefore, accounts will be more reliable and techniques such as the cognitive interview use these methods to ensure a detailed accurate account and avoid false convictions.
what is meant by ‘stress and arousal’? reference the Yerkes Dodson model.
- witnesses are under stress when witnessing an event/crime.
- the Yerkes-Dodson Law states that there is an optimum level of stress arousal in a situation that leads to the best memory performance
- there are also levels of being under-aroused and over-aroused that will lead to an poor performance in memory
what is a strength of stress and arousal as a factor affecting EWT reliability (PEEA)?
- supporting evidence
a strength of stress and arousal as a factor affecting EWT reliability is supporting evidence from Valentine and Mesout. this is because they found that when people were scared in the london dungeons, they showed high anxiety levels and this reduced their ability to identify a perpetrator. therefore this suggests that the emotional state of the witness effects memory accuracy. additionally, this research has good ecological validity. for example, it took place in a natural setting and ppts were unaware of the study. therefore, this limits the risk of demand characteristics affecting results and means findings are accurate to stress affecting EWT in real life.
what is a strength of stress and arousal (PEECA/)?
- applications
a strength of stress and arousal as a factor affecting EWT reliability is the practical applications. for example, it suggests that when gathering EWT accounts the police should also measure their stress level. therefore, this means that a more accurate account can be obtained and wrong convictions can be avoided. however this can be limited as it doesn’t suggest ways to improve the accuracy due to not being able to advise people to reach the optimum level of arousal.
what is a weakness of stress and arousal (PEE)?
- criticism
a weakness of stress and arousal as a factor affecting EWT reliability is that arousal is difficult to operationalise. for example, it can result from fear or increased alertness. therefore, his makes comparisons difficult due to having inconsistent definers for arousal.
