Factors affecting the accuracy of eyewitness testimony

including misleading information; leading questions, post event information and discussion; anxiety

what is an eyewitness testimony?

information given by people who have seen an event happen e.g. a crime

what is a limitation of eyewitness testimonies?

they are not always accurate

what are the implications of eyewitness testimonies not always being accurate?

problematic as its used in court cases which can lead to wrongful imprisonment

what are the two main forms of misleading information?

• leading questions

• post-event discussion

what is a leading question?

the way a question is phrased can suggest a certain answer and influence an individual to give a desired response

what is post-event discussion?

speaking about an event with others after it has occurred which can implicate the accuracy of recall and add extra details that didn’t happen

who did a study investigating leading questions?

loftus and palmer (1974)

what was loftus and palmer’s study on leading questions?

• 45 Ps were shown 7 videos of car accidents

• they were asked ‘how fast were the two cars going when they _____ each other?”

• they used verbs ranging from severe (“smashed”) to mild (“bumped”)

what were the results of loftus and palmer’s study on leading questions?

the “smashed” group gave a higher estimate for the speed of the two cars compared to the “hit” group

• smashed = mean estimated speed of 40.8mph

• hit = mean estimated speed of 34mph

in loftus and palmer’s study on leading questions, when asked a week later “did you see any broken glass?” what were the results?

smashed group = 32% said yes

hit group = 14% said yes

in loftus and palmer’s study on leading questions, why would it have been necessary to randomly allocate the groups?

to avoid participant characteristics from affecting the study e.g. less confident/more easily led people

why does loftus and palmer’s study on leading questions lack mundane realism?

they’re watching it through a TV screen instead of actually seeing the collision

how could demand characteristics affect the results of loftus and palmer’s study on leading questions?

if you’re given stronger/weaker verbs, you may give a faster/slower speed, or feel like you need to, compromising the validity of the results

what implications does loftus and palmer’s study have for interviewing eyewitnesses and police training?

• can be used to improve CIT as police training can be taught to use less leading Qs

• leading Qs negatively impact accurate recall - police ask open ended Qs instead e.g.

  • “tell me everything”

  • “what happened next?”

who investigated post-event information?

loftus and pickrell (2003)

how did loftus and pickrell investigate post-event information?

• 120 students who’d visited Disneyland as a child

• 4 groups asked to read an advert and answer Qs about their trip

  • group 3 → fake ad featuring bugs bunny

  • group 4 → fake ad featuring bugs bunny and cardboard figure

what were the results of loftus and pickrell’s study into post-event information?

• 30% Ps in group 3

• 40% Ps in group 4

said they remembered meeting bugs bunny (which is impossible as he is a warner bros character)

who investigated the effects of post-event discussion?

gabbert et al. (2003)

how did gabbert et al. investigate post-event discussion?

60 students from uni of aberdeen and 60 adults

2 simulated videos: one was normal, one featured the girl committing act of theft

people in pairs told they had watched the same video but had each watched a diff one → allowed to talk to other Ps after watching them

what were the results of gabbert et al. investigation into post-event discussion?

• 71% of Ps said they remembered info they had not seen in the video

• 60% who had not seen the girl commit a crime said she was guilty

what are the implications of post-event discussion for the police?

police train officers not to judge statements of multiple witnesses as more accurate just because they have the same information

give a limitation of the investigations into misleading information.

lacks ecological validity → in real life you may not pay as much attention to your surroundings, but when asked to watch a video you are already honing in on the surroundings

what could memory distortion be caused by as well as post-event information?

conformity effects and informational social influence (ISI)

what is ‘weapons focus’ and who proposed it?

loftus → an eyewitnesses focus on a weapon leading to the exclusion of other details in a crime

who conducted an investigation testing loftus’ theory of weapons focus?

johnson and scott (1976)

what was the investigation johnson and scott (1976) carried out investigating weapons focus?

• Ps sitting in waiting room thinking they are taking part in lab study

• they hear argument in next room and see a man walk out with something different in his hands

  • low anxiety condition and high anxiety condition

what were the low anxiety and high anxiety conditions in johnson and scott’s (1976) investigation?

low anxiety → man walks through waiting room carrying a pen w/ grease on his hands

high anxiety → overheard sound of breaking glass + man walks through carrying paper knife covered in blood

what were the results of johnson and scott’s (1976) investigation into weapons focus?

when Ps had to pick out suspect who walked through waiting room:

• pen - 49% remembered

• knife - 33% remembered

supporting weapons focus

who proposed a potential positive effect of anxiety on eyewitnesses and what is it?

yuille and cutshall (1986) → fight or flight due to anxiety may make the individual more alert as the senses become heightened

what is a limitation of johnson and scott’s investigation into weapons focus?

the study may have tested surprise and not anxiety

who investigated the limitation of johnson and scott’s weapons focus study that they may have tested surprise, not anxiety?

pickel (1998) → using a video in a hairdressers

chicken had the lowest recall

what is an ethical issue of johnson and scott’s weapons focus investigation?

potential distress caused to Ps