psychology eye witness testimonies Flashcards
what did loftus and palmer study and find
arranged 45 pps to watch car acciednt
split into 5 groups each got a different verb of the crash eg contacted smashed bumped
asked to describe how fast the carw as going
verb contacted resulted in mean speed of 30.8mph
verb smashed resulted in mean spped of 40.5
why do leading questions affect ewt
response bias- influenced by question to change response
substitution explanation- changes pps memories
what did gabbert study and find
studied pps in pairs watched a video of the same crime but filmed from different povs
each pps could see elements the other couldnt and then they discussed what they had seen
found 71% recalled what they had picked up in the discussion compared to control group of 0%
evidence of memory conformity
why does post event discussion affect ewt
memory contamination- witness memories become distorted because they combine info of their memories with the other persons
memory conformity- go along with the other witness to either gain social approval or because they think the other person is right and they are wrong but the mem is unchanged
what are the real world application evaluation (misleading info)
- important pracitcaly uses in criminal justice system
- lets police know they need to be careful about questioning as it can affect ewt
- psychologists invited to be expert witnesses to explain limits of ewt to jury
- psychologists can help to improve the way legal system works and prevent faulty convictions
- practical applicatons may be affected by issues with research
- loftus and palmer used film clips different experience to being involved
- foster- what the ew remembers has important consequences in real world but doesnt matter the same in research
- research is too pessimistic about the effects
- ewt may be more dependable than some studies suggest
what are the evidence against substitution points (misleading info)
- subsitution explanation is more accurate for some aspects of events than others
- sutherland and hayne- showed pps clips and when asked leading questio their recall was accurate for central details than peripheral ones and attention was focused on central features and these memories were more resistent to misleading info
what are the evidence challenging memory conformity (misleading info)
- memory conformity is vidence that post event discussion alters ewt
- skagerburg and wright- ahowed pps two versions of clips in pairs, each saw different video, discussed in pairs, didnt report what they had seen or heard but a combo
- memory itself distorte d through montamination of misleading post event discussion rather than memory conformity
what did johnson and scott study and find
put pps in high and low anxiety conditions
- low anxiety- overheard discussion and saw man walk out with pen and greasy hands
- high anxiety- overhead heated argument and breaking glass and saw a man come out with knife and blood on hands
asked to recall out of 50 pictures of man- 49% in low and 33% in high
supports tunnel theory- focus on the weapon
what did yuille and cutshall study and find
actual shooting in gun shop, owner shot a thief dead
21 witnesses and 13 took part in study
interviewd 4-5 months apart and were compared with orignial police interviews at the time
accuracy based off the amount fo correct details
asked to rate their stress levels on a 7 point scale and if they had any emotional psychological problems sleep eg not sleeping
those with the higher stress level 88% and those with the lower stress level 75%
anxiety doesnt have detrimental effect on recal and may even enhance it
what is yerkes dodson law
witness a crime emotionally and physiologically aroused
higher levels of anxiety= higher levels of ercall
lower levels of anxiety= lower levels of recall
optimim point of anxiety where memory takes drastic decine
what are the unusualness not anxiety points (anxiety
- may not have tested anxiety
- pps focused on weapon because they were surprised inetead of anxious
- pickel= study in hair salon using scissors in one condiiton and chickne and handgun in another, those in high unusualness had poorer recall
- weapon focus effecti is due to unusualness rather than anxiety, doesnt tell us about the effects of anxiety on recall
what are the support for positive effects points (anxiety)
- can have positive effect on accuracy
- researchers interviewd 58 witnesses to actual bank robberies, some directly involved and some indirectly, all recall was above 75% and those directly involved had higher recall
- confirms anxiety doesnt reduce accuracy and may even enhance it
- researchers interviews their pps several months later- had no control over what happened in intervening time and affects of anxiety may have been overwhelmed by other factors and impossoble to assess by the time pps were interviewed
- possibel lack of control over confounding variables may be responsoble for these findings invalidating their support
what are the support for negative effects points (anxiety)
- negative effect on accuracy support
- valentine and mesout- used objective measure divide pps into high and low anxiety groups anxiety disrupted ability to recall details about actor in london dungeons labrinth
- high level of anxiety does have negative effect on immediate ew recall ofstressful event
