Factors affecting EWT

Question 1

What is an eye witness testimony?

Answer 1

• Evidence provided in court by a person who witnessed a crime
• Person tries to identify the perpetrator

Question 2

What are 3 factors that affect the accuracy of EWT?

Answer 2

1. Misleading information, leading questions
2. Misleading information, post event discussion
3. Anxiety

Question 3

What is misleading information?

Answer 3

• Incorrect info given to the eyewitness (after the event) that affects their recall

Question 4

What are leading questions as part of misleading information?

Give 2 examples?

Answer 4

• A question by phrasing or content suggests a desired answer
• Leads witness to believe a desired answer is required
• Leading questions contain misleading pieces of info or wording & are closed questions
• Reduce accuracy of EWT

e.g.
- ‘Did you see the man in the red coat?’
- ‘You didn’t see any young people, did you?’

Question 5

What has research demonstrated about leading questions?

Answer 5

• Identity of interviewer can make a difference to how impactful they are
• Due to reconstructive nature of memory, leading questions alter original memories of a crime

Question 6

Explain 2 sets of research into leading questions in EWT?

Answer 6

Loftus & Palmer (1974)
- Asked Pt’s to estimate speeds of vehicles using different types of words:
- ‘Contacted’: 32mph
- ‘Hit’: 34 mph
- ‘Bumped’: 38 mph
- ‘Collided’: 39 mph
- ‘Smashed’: 41 mph

• Found: Leading questions significantly effect EWT

Loftus & Zanni (1975)
- Pt’s viewed a film of a car crash
- Pt’s then asked a definitive question/non-definitive question of an event that never happened
e.g.
- ‘Did you see a broken headlight?’ (non definitive)
- ‘Did you see the broken headlight?’ (definitive)

• 17% of Pt’s replied saying they had seen broken headlight (definitive)
• 7% of Pt’s replied saying they had seen broken headlight (non-definitive)
• Found: Even one word can make ETC less accurate in a leading question

Question 7

AO3 leading questions
Generalisability?
participants in research = students

Answer 7

P - Lacks generalisability as typically research is conducted on students
E - Creates problems generalising to target population as psychology students are not representative of the target population
E - Studies are limited in its use in explaining leading questions on accuracy of EWT
L - Findings cannot be generalised to everyone only the psychologists’ students

Question 8

AO3 leading questions
Practical applications?
Kohnken (1999)

Answer 8

P - Useful practical applications
E - Research into leading questions has led to enhanced cognitive interview (ECI) used by Police
E - Helps to reduce errors made by EW’s by eliminating use of LQ’s & allowed EW to report everything they remember without interruption
- Kohnken (1999) reviewed 53 studies & found ECI led to 34% increase in accuracy
L - Cognitive interviewing can increase the conviction rate & right person is more likely to be convicted thus improving justice system

Question 9

AO3 leading questions
High internal validity?
Loftus & Palmer (1974)

Answer 9

P - Most research into LQ using well controlled lab experiments giving research high internal validity
E - We have confidence that it is the IV causing the DV (effect) & not any extraneous variables
E - Loftus & Palmer (1974) change in verb (IV) changed the speed of the car estimate (DV) so we can make statements about cause & effect
L - This means research into LQ can be seen as more credible research that can be used to show a legitimate factor affecting EWT

Question 10

AO3 leading questions
Low ecological validity?

Answer 10

P - However research is also artificial lab experiments & so is low in ecological validity
E - research takes place in a lab with controlled settings that are not naturalistic & do not reflect real life behaviour
E - Loftus & Zanni (1975) Pt’s watched a film of a car accident which is not the same as seeing a car accident on the street
- So stress/anxiety absent & films are made for entertainment purposes
L - Makes it difficult to generalise the findings of the studies to real life eyewitness memory

Question 11

What is post event discussion?

What 3 factors can lead to post-event discussion?

Answer 11

• Witnesses to a crime discuss events with others (including other EW’s)
• Their memories become contaminated
• Police then get concerned over quality of evidence
• Retroactive interference/media coverage
• Conformity
• Repeat interviewing

Question 12

How can retroactive interference/media affect & damage EWT?
(post event discussion)

Answer 12

• If witness feels compelled to change their statement if media sharing info that doesn’t match their WT of event
• Through recent similar info affecting memory of old similar info

Question 13

How can conformity affect & damage EWT?
(post event discussion)

Answer 13

• ISI: Follow a different narrative to your own because you believe the other witness to be right
• NSI: Change your opinion as others have a different opinion, you do this to be accepted & not an outlier
• In EWT both can occur to be either correct/accepted

Question 14

How can repeat interviewing affect & damage EWT?
(post event discussion)

Answer 14

• Asking same question twice implies first answer was incorrect & second question should be answered differently

Question 15

Research evidence for post-event discussion?

Answer 15

Gabbert (2003)
- 60 students (Uni Aberdeen) & 60 older adults (local area)
- Pt’s watched video of girl stealing money from wallet
- Pt’s tested individually (control group) or in pairs (co-witness group)
- Pt’s in co-witness group were told were told they saw same video, in actual fact saw video from different perspectives of same event (their video had no crime in)
- Pt’s in co-witness discussed ‘crime’ together
- All Pt’s did questionnaire testing memory of video

• Found 71% witnesses (co-witness group) recalled info they hadn’t seen & 60% said girl was guilty despite not seeing her commit crime
• Results highlight post-event discussion having effect on EWT accuracy

Question 16

AO3 post-event discussion
Research evidence?
Gabbert (2003)

Answer 16

P - Research support from Gabbert (2003)
E - Summarise Gabbert here
E -
L - Showed post-event discussion can significantly effect accuracy of EWT

Question 17

AO3 post-event discussion
Gabbert does not take into account individual differences between Pt’s?

Answer 17

P - Gabbert (2003) did not take into account other factors that can affect accuracy of EWT
E - Individual differences between Pt’s were not taken into account
- Found: older Pt’s were less accurate than the students at providing EWT & age groups are more accurate when identifying people of their own age
E - Research studies often use younger people to be identified & so some age groups may appear less accurate but this is not the case
L - Implies individual differences may affect the results of research into post event discussion

Question 18

AO3 post-event discussion
Low ecological validity?

Answer 18

P - Research evidence suffers from low levels of ecological validity due to laboratory settings when studying EWT
E - Gives rise to demand characteristics meaning Pt’s able to guess aim of study
E - So may change their behaviours to ‘help’ the researcher or damage the results
L - Research support for effects of post-event discussion on accuracy of EWT may lack credibility

Question 19

AO3 post-event discussion
Practical applications?

Answer 19

P - Practical applications to help society & justice system
E - When people come forward after a crime to give evidence this helps police establish who the perpetrator is
E - The police know about post-event discussion & so will mitigate it & prevent witnesses from conferring with each other for risk of corrupting legitimate descriptions of an event
L - Suggests the prevention of post-event discussion can prevent the corruption of evidence improving the justice system & preventing further criminality

Question 20

How can anxiety affect accuracy of EWT?

Answer 20

• Witnesses may be highly aroused if stressed/anxious
• This happens if there was a threat/danger in the criminal event/if witness is the victim
• Some witnesses may naturally be anxious

Question 21

What is the Yerkes-Dodson law & what does it suggest?

Answer 21

• Predicts how anxiety affects our performance
• Model of relationship between stress & task performance
• Proposes you reach peak level of performance with intermediate level of stress/arousal
• Too little/too much arousal results in lower performance
• Known as inverted U theory
• Performance peaks when arousal is in a medium central position (between low & high) on the graph

Question 22

Explain the weapons focus effect?

Answer 22

• If threat posed at a crime or towards the witness is in form of weaponry they may remember more about the thing that poses the threat vs other details
• A weapon focus effect occurs when a weapon distracts eyewitness
• This harms memory of the perpetrator & other details due to anxiety fostered by the presence of a weapon

Question 23

Research evidence for weapons focus effect?

Answer 23

Johnson & Scott (1976)
- 49% of Pt’s correctly recalled the man when holding a pen compared to 33% when holding a paper knife, weapon

• Findings support weapons focused effect and effect anxiety has on EWT

Question 24

Research evidence for effect of anxiety on EWT?

Answer 24

Deffenbacher (2004)
- Meta-analysis of 63 studies & found increase in EWT accuracy up to high levels of anxiety
- But extreme anxiety decreased accuracy of EWT

• Findings supports idea anxiety makes EWT less accurate

Loftus & Burns (1982)
- Pt’s who saw violent incident of robbery recalled less than Pt’s who saw robbery film without violence
- Suggests anxiety caused by violence decreased accurate recall

• Findings supports idea anxiety makes EWT less accurate

Question 25

AO3 anxiety on EWT accuracy
research high internal validity?
Loftus & Burns (1982)

Answer 25

P - Research high levels of internal validity
E - Lab experiment (Loftus & Burns 1982) on violence & anxiety were well controlled so we can study cause & effect
E - In Loftus & Burns level of violence in the robbery was IV & the accuracy of EWT was DV
L - Means violence from event resulted in high levels of anxiety which disrupted accuracy of EWT

Question 26

AO3 anxiety on EWT accuracy
Research low in ecological validity?

Answer 26

P - Research often relies on lab experiments meaning research is low in ecological validity as its not the same as witnessing a real violent crime
E - In an experiment crimes are displayed on a television, meaning Pt’s pay more attention vs real life
E - Also its far less realistic & anxiety-provoking than being subjected to the real crime e.g. smell of gun fire/sounds of people screaming
L - Implies in experiments your not going to act naturally vs behaviour in real-life
- Means effect of anxiety & weapons focus effect on EWT is less credible

Question 26

AO3 anxiety on EWT accuracy
Research high reliability?

Answer 26

P - High level of control in research increases reliability
E - Research uses experimentation & standardised procedures allowing research to be replicated
E - In Loftus & Burns (1982) there were 2 experimental conditions (violent shooting robbery & non-violent robbery)
L - So study can be replicated with ease to check findings are consistent

Question 27

AO3 anxiety on EWT accuracy
Research is inconsistent?
Christianson & Hubinette (1993)

Answer 27

P - Research findings are inconsistent, research into recall from real incidents involving high levels of stress indicate memory can be accurate, detailed & long lasting
E - Christianson & Hubinette (1993) carried out survey of 110 people who witnessed between them 22 bank robberies - some bystanders, others directly threatened by robbers
E - Victims (those subjected to most stress/anxiety) were more accurate in EWT
L - Contradicts what experimental research has found
- Suggests in a real-life situation where anxiety & fear is at its maximum EWT is most accurate vs inverted u theory prediction