factors affecting eye witness testimony

Question 1

Factors that affect accuracy of the eyewitness reports

Answer 1

Misleading information

• leading questions
• postevent discussion
• -> info received after the event can lead to retroactive interference

Anxiety

Question 2

What is a leading question

Answer 2

A leading question that is either by form or content suggests to the witnessed what answer is desired

Question 3

Evidence supporting the effect of leading questions on the accuracy of eyewitness testimonies

Answer 3

LOFTUS + PALMER (1)
→ independent measures design ∴ no ind. diff
divided 45 US students, into 5 groups of 9. all pts watched a video of a car crash + asked a specific Q about the speed of the cars. L+P changed the verb (IV) used in the Q, e.g, “How fast were they cards going when they smashed/ collided/ bumped/ hit/ contacted with each other?”. FOUND: estimated speed was affected by the verb used. For example, participants who were given the verb ‘smashed’ reported an average speed of 40.5 mph, whereas participants who were given the word ‘contacted’ reported an average speed of 31.8 mph. TS accuracy of eyewitness testimony is affected by leading questions + that a single word in a question can significantly affect the accuracy of our judgments.
BUT
Ambiguous task: pts could be unsure whether 30 or 40 mph, ∴ use verb to form a response

LOFTUS + PALMER (2)
diff sample of 150 US students, divided into 3 groups. All of the pts watched a 1 min vid showing a car accident + then given a questionnaire. 1 group was asked: “How fast were the cars going when they smashed into each other?”, other group was asked: “How fast were the cars going when they hit each other?”, final group (control) was not asked about the speed of the vehicles. 1 week later pts returned + asked Qs about the accident. The critical question was: “Did you see any broken glass?” There was no broken glass in the video clip. FOUND:32% Qed w/ the verb smashed reported seeing broken glass; 14% Qed w/ the verb hit reported seeing broken glass; + 12% of control reported seeing broken glass. TS idea of memory of original event being distorted by leading Qs

Question 4

LOFTUS + PALMER evaluation

Answer 4

Lack ecological validity: pts watched a video of a car crash + witnessed the events unfold from start to finish. normally, witnesses rarely see the whole event∴ results do not reflect everyday car accidents + so unable to conclude if eyewitnesses to real accidents would be affected in the same way. YUILLE + CUTSHALL found misleading info didn’t alter mem of those who witnessed a real armed robbery. TS misleading info may have a greater influence in the lab than real life

internal validity: same vid, script ∴ replicable, establish cause + effect
BUT DC → verb easily identified ∴ ambiguity in causality
Lacks population validity: all US uni students → Culture? Age? WARREN: kids more influenced by misleading Qs than adults. Also more experienced drivers may have better speed judgement

experimental reductionism: the complex process of memory after a film of what would in real‐life be a traumatic event is reduced to the effect of the wording of a leading question (IV) on the eyewitness memory (DV). ALSO cultural bias, as samples of pts were from western countries 


Question 5

What is post event discussion

Answer 5

When co-witnesses discuss events with one another

EWT may be contaminated this is because they may combine other information with their own

Question 6

Related research into postevent discussion: GABBERT

Answer 6

→ 60 uni students + 60 older adults from Aberdeen
pts watched vid of a girl stealing money from a wallet. pts tested individually (control group) or in pairs (co‐witness group). pts in the co‐witness group told that they had watched the same video; however, they saw diff perspectives of the same crime + only 1 person actually witnessed the girl stealing. pts in the co‐witness group discussed the crime together. All pts completed a questionnaire, testing their mem of the event. FOUND: 71% of co‐witness group recalled info they didn’t actually see + 60% said that the girl was guilty, despite the fact that they had not seen her commit a crime. TS the issue of post‐event discussion + the effect it has on the accuracy of EWT

Question 7

GABBERT EVAL

Answer 7

• LACKS ECOLOGICAL VALIDITY: pts in co‐witness condition saw diff perspectives of the same crime, as would typically be the case in real‐life crimes. BUT witnesses knew they were taking part in an experiment + ∴ more likely to have paid close attention to details of the vid. ∴, these results do not reflect everyday examples of crime, where witnesses may be exposed to less information.
• Tested 2 diff pops, uni students + older adults, + found little diff between 2∴ good population validity + allow us to conclude PED affects younger and older adults in a similar way. 
BUT, what about younger ages? Other cultures (only done in Aberdeen)

Question 8

Related research into postevent discussion: LOFTUS + PICKRELL

Answer 8

24 pts (18-53) 4 stories about childhood provided by relatives, 3 true but 1 false. False mem = lost at dept store at 5 y/o + rescued by an old lady. Pts asked if they recalled these memories. 68% of true mems recalled + 29% of false mems recalled. TS false memories can be created from suggestion. i.e supporting idea of PED as info suggested by co-witness may implant false memories

Question 9

Outline weapon focus as suggested by Easterbrook

Answer 9

Concentration of weapon during the crime means less attention available for viewing other things

CUE UTILISATION HYPOTHESIS
Presence of a threat (e.g, weapon) would naturally incr. level of anxiety
∴ decr. Witness attention capacity
This means: witness focus on central cues (weapon) rather than peripheral cues (face) (KRAMMER)

Question 10

Related research into weapon focus + EVAL

Answer 10

LOFTUS / JOHNSON + SCOTT
pts invited to lab, told to wait in the reception area where they overheard a convo.
→independent groups design, pts exposed to 1 of 2 
 conditions: 1) harmless convo + confed walked past pts holding a pen. 2) pts overheard a hostile convo confed walked out with blood covered letter opener
Both then shown 50 pics + asked to identify confed. FOUND: pen condition correctly identified the target 49% of the time, vs knife condition, correctly identified the target 33% of the time.
Knife condition had higher levels of anxiety + more likely to focus their attention on the weapon and not the face of the target. TS idea of weapon focus.

IGD → no DC as only exposed to 1 condition ∴ cant guess IV
LAB lacks mundane realism BUT pts not expecting knife crime ∴ like real life
ETHICS: psychological harm but over come w/ debrief // lack of informed consent ∴ get retrospective consent
INVALID CONCLUSION: doesn’t measure level of anxiety / where pts are looking

Question 11

Limitations to weapon focus hypothesis

Answer 11

THREATENING OR UNUSUAL?

PICKEL: found accuracy of pts of an event in hair salon was affected by an unusual object rather than a threatening one. TS weapon focus phenomenon may be due to the fact of its unusualness ∴ is not reliant on anxiety

CHRISTIANSON + HUBINETTE: victims (who experience more stress) of genuine bank robberies where more accurate in their recall than bystanders (experience less stress). TS anxiety / stess does affect recall

With conflicting evidence, it may be best to apply it to
YERKES DODSON LAW: relationship between arousal + performance ∴ anxiety has a pos effect on recall up until a certain point, past this it has a neg effect

Question 12

Eyewitness testimony IDA

Answer 12

all use a nomothetic approach to try to establish universal laws regarding eyewitness testimony, but their claims are based on small, non‐ representative samples.