factors that effect eye witness testimony ( case studies)

leading questions and reconstructive memory already covered in my other notes!read those before reading this :)

yerkes dodson curve.not research but shows that the lower the stress.the less memory you have but also the higher the stress the less memory you have,you have to have a balnce of stress to have the highest amount of memory possible.not one of the 2 extremes.

clifford and scott

yuille and cutshull

these people studied how eyewitness testimony is effected by anxiety and stress

clifford and scott

experimental group : saw violent version of attack on video

control group:saw less violent attack on video

both groups asked to recall 40 pieces of info

results:experimental group remember less.the higher the stress the less we remember.stress badly effects EWT

disadvantage:ecological validity in artificial enviorment and demand characteristics.its a video!not real life/results not generalised 

• those more stress more accurate.anxiety enhanced with accuracy
• real world happenings.
• witnesses to real life shooting
• outside gun shop where thief killed 
• interviewed immedicatly after and 5 months later to see if memory changes
• results:recall accurate even when asked misleading questions
• Yuille and cutshull happened in real world.clifford and Scott in lab.people look to this study more

loftus

parts outside lab overhears heated discussion and man runs past them

condition 1:man runs out holding pen and hand covered in grease/oil

condition 2:man runs out holding paper knife and knife covered in 'blood'

• when asked to recall man who ran parts in condition 1 more accurate 
• part in condiction 2 focused on weapon,.not the face of the man
• weapon=stress=less accurate EWT
• lab experiment,so low ecological validity and demand characteristics

110 people surveyed

they witnessed 22 bank robberies between them

 remembered more if in real life-the most stressed people

not in artificial lab but real world happenings

results:witnesses threatened had greater accuracy in recall.other witnesses may have been outside!or not threatened at all and so don't remember much.

children 3 to 8 years participated in science experiment 

interview after immediately 

then read story by parents with misleading info(they trust parents)

hidden in story was misleading info on experiment that's false

re interviewed

results:kids accurate when immediately interviewed(1 percent false)

after misleading story read,then memories changed

KIDS HIGHLY SUGGESTIBLE AND POOR AT SOURCE MONITERING

they believe parents

implications:kids used in court cases(mainly abuse cases).parents who re trusted can intentionally or unintentionally alter their memory

Yarmey

witnessed stage event and asked questions

young adults:20 percent didn't recall knife

older adults:80- percent didn't recall knife

older adults less accurate memory.adults lose memory over time

Young adults are better witnesses

Coxon and Valentine

young people have better memory but older people are less suggestible

children-8yrs average

young adults-17 yrs average

old adults-70 years average

they were the experimental groups

witnessed kidnapping video and asked questions

experimental groups fed misleading information

results: young adults have best memory.old people have 66 right memory and young adults have 77 percent right memory

however old people are less suggestible because when they were fed misleading info after ,they didn't have their memory 'changed'

old: from 66 to 50 percent(lose 10 percent memory after midleasding info fed to them)

young: from 77 to 52 percent (lose 25 percent memory after misleading info fed to them)

Flin etal

children and adults witnessed same incident

interviewed 1 day and 5 months after

results:no difference in memory of kids /adults 1 day after

5 months after:adults more accurate.they can retain more information.kids memory affected by time.

implications: when kids used in court cases,it takes time to actually get to court so by then they could be less accurate

• lab studies lack ecological validity
• parts can be more accurate if answer 'not sure'
• parts can be more accurate if asked questions in logical order-misleading questions then have no effect