6: Factors affecting the accuracy of Eyewitness Testimony

Question 1

what is eyewitness testimony

Answer 1

EWT is a legal term used to describe the evidence provided in court by a person who was present at the time a crime took place
the purpose of gathering EWT is to identify the criminal involved

Question 2

what factors have been identified as affecting the accuracy of EWT

Answer 2

• misleading information (in the form of leading questions or post-event discussion)
• anxiety

Question 3

what is misleading information

Answer 3

incorrect info given to the eyewitness usually after the event has taken place

can take place in many forms including leading questions and post-event discussion

Question 4

what are leading questions

Answer 4

questions that suggest a certain answer

eg: “you saw the knife, didn’t you?”

Question 5

what is post-event discussion

Answer 5

where two witnesses have a conversation after a crime has taken place

Question 6

why might post event discussion affect the accuracy of EWT

Answer 6

• could combine information/misinformation from the other’s recollection with their own
• may think the other is right and they are wrong
• may agree with the other due to ‘memory conformity’ to win social approval

Question 7

who did research into the effects of leading questions on the accuracy of EWT?

Answer 7

Loftus and Palmer (1974)

Question 8

Description - Loftus & Palmer’s research into leading questions:
aim

Answer 8

aimed to investigate the effects of misleading info (in the form of leading questions) on the accuracy of EWT

Question 9

Description - Loftus & Palmer’s research into leading questions:
procedure

Answer 9

• laboratory experiment
• 45 students
• shown 7 films of diff car accidents
• given questionnaire to describe the incident with one critical question: “about how fast were the cars travelling when they hit each other”
• other groups: ‘hit’ changed to smashed, collided, bumped, contacted
  -calculated mean estimated speeds for each condition

Question 10

Description - Loftus & Palmer’s research into leading questions:
findings

Answer 10

mean estimated speeds:

smashed: 40.8
collided: 39.3
bumped: 38.1
hit: 34
contacted: 31.8

Question 11

Description - Loftus & Palmer’s research into leading questions:
conclusion

Answer 11

misleading info in the form of leading qs can indeed affect the accuracy of EWT and it may cause the info to be changed before it is stored, so that the memory is permanently affected

Question 12

Evaluation - Loftus & Palmer’s research into leading questions:
strengths

Answer 12

P: practical applications
E: warn justice system for potential problems w EWT
E: warn juries against fully trusting EWT, should take into account a range of evidence
L: avoid inaccurate judgements being made in court

P: lab experiment: high control over variables
E: artificial setting so EVs can be controlled
E: L&P can standardise environment (eg noise, lighting) and materials (questionnaire) for all pps when viewing the films
L: high internal validity: measures what it intends to measure

P: easy to replicate
E: control setting - materials/procedures can be repeated for further replications of the study
E: L&P can use the same films/verbs
L: findings easily tested for reliability

Question 13

Evaluation - Loftus & Palmer’s research into leading questions:
limitations

Answer 13

P: criticism from Yuille & Cutshall (1986)
E: real robbery in Canada, 4 months later 13 eyewitnesses weren’t affected by leading questions - responded same as they did in initial report
E: misleading info doesn’t affect real life EWT, possibly due to the level of anxiety/emotions faced
L: L&Ps findings don’t generalise to real EWT as laboratory conditions lack the emotions of real crimes

P: low ecological validity
E: artificial setting - doesn’t represent real life EWT
E: mock crimes lack the consequences of real life EWT, pps more likely to let themselves be influenced by leading questions
L: findings can’t be generalised to real life EWT

Question 14

who did research into the effects of post-event discussion on the accuracy of EWT?

Answer 14

Gabbert et al (2003)

Question 15

Description - Gabbert’s research into post event discussion:
aim

Answer 15

aimed to test the effects of post event discussion in the accuracy of EWT

Question 16

Description - Gabbert’s research into post event discussion:
procedure

Answer 16

• laboratory experiment
• 120 participants
• put into pairs/ shown video of the same event from diff POV
• each pp could see elements the wither couldn’t
• eg only one could see the girl steal a £10, only the other could see the name of the book she was returning
• pps discussed what they had seen before individually completing a test of recall

Question 17

Description - Gabbert’s research into post event discussion:
findings

Answer 17

71% mistakenly recalled aspects that they hadn’t seen in the video but picked up in the discussion
(corresponding figure in control group was 0%)

60% of pps who didn’t see the crime reported the girl as being guilty

Question 18

Description - Gabbert’s research into post event discussion:
conclusion

Answer 18

witnesses often go along with each other due to ‘memory conformity’: going along with the testimony of others either to win social approval or because they believe the other is right and they are wrong

Question 19

Evaluation - Gabbert’s research into post event discussion:
strengths

Answer 19

P: support from Bodner et al (2009)
E: found similarity strong effects of PED on accuracy of EWT
E: these effects could be reduced by warning pps abt the negative effects of listening to ‘second hand information’
L: supports the strong influence memory conformity on EWT accuracy

P: practical applications
E: warn justice system for potential problems w EWT
E: warn juries against fully trusting EWT, should take into account a range of evidence
L: avoid inaccurate judgements being made in court

P: lab experiment: high control over variables
E: artificial setting so EVs can be controlled
E: Gabbert: ensure all pps discussion time is standardised
L: high internal validity: measures what it intends to measure

P: easy to replicate
E: control setting - materials/procedures can be repeated for further replications of the study
E: Gabbert: same video, discussion time, confederate
L: findings easily tested for reliability

Question 20

Evaluation - Gabbert’s research into post event discussion:
limitations

Answer 20

P: laboratory: mock crimes lack the consequences if real-life crimes
E: artificial setting: pps aware that their testimony doesn’t have as serious consequences as in real life, where someone can be wrongly convicted/freed
E: may not have said the girl was guilty if they hadn’t seen it themselves
L: low ecological validity: Gabberts findings don’t accurately represent real life EWT

P: demand characteristics
E: aware they are being studied, act unnaturally
E: eg may work out the aim of the experiment and be less susceptible to influence of PED, or give the results they think are intended
L: low internal validity as not measuring true behaviour, and the findings cant be generalised to real life effects of PED

Question 21

what is anxiety

Answer 21

a state of emotional and physical arousal
emotional changes may include worried thoughts and feelings of tension
physical changes may include an increased heart rate and rapid breathing

Question 22

explain the weapon-focus effect

Answer 22

presence of a weapon increases anxiety.
makes the EW focus on central details (eg the weapon) rather than peripheral details (eg what else was going on)
this mean the EW may struggle to recall key details of what they saw (eg the face of the attacker) as they are so focused on the weapon, making EWT less accurate

Question 23

who did research into the effects of anxiety on the accuracy of EWT

Answer 23

Johnson and Scott (1976)

Question 24

Description - Johnson & Scotts research into anxiety:
aim

Answer 24

aimed to study the effects of the anxiety caused by the presence of a weapon on the accuracy of EWT

Question 25

Description - Johnson & Scotts research into anxiety:
procedure

Answer 25

• lab experiment
• independent groups design
• two conditions: C1 heard discussion and saw man holding pen w grease (non-anxiety), C2 heard more heated discussion and saw man holding knife w blood (anxiety)
• asked to identify man from 50 photos

Question 26

Description - Johnson & Scotts research into anxiety:
findings

Answer 26

C1: 49% accurate

C2: 33% accurate

Question 27

Description - Johnson & Scotts research into anxiety:
conclusion

Answer 27

anxiety cause by the weapon narrowed the focus of attention (W-F E) making their recall less detailed/accurate.

may explain why EW may have poor recall for certain violent crimes

Question 28

Evaluation - Johnson & Scotts research into anxiety:
strengths

Answer 28

P: support from Loftus et al (1987)
E: presence of a weapon causes eye movements to be drawn to weapon/away from other things
E: weapon focus effect - affects focus of attention
L: supports that anxiety by a weapon causes decrease in EW accuracy, explains bc of a shift in visual attention

P: Yerkes-Dodson Law explains the apparent contradiction in research on anxiety
E: can help up to an optimal point, but too much can reduce the accuracy
E: J&S weapon focus research occurred bc it put pps beyond optimal point
L: supports J&S research while also explaining research like Christianson & Hubinette (1993)

P: practical applications
E: warn justice system for potential problems w EWT
E: warn juries against fully trusting EWT, should take into account a range of evidence
L: avoid inaccurate judgements being made in court

P: lab experiment: high control over variables
E: artificial setting so EVs can be controlled
E: J&S could use same researcher/conditions
L: high internal validity: measures what it intends to measure

P: easy to replicate
E: control setting - materials/procedures can be repeated for further replications of the study
E: same items held by man, same 50 pictures
L: findings easily tested for reliability

Question 29

Evaluation - Johnson & Scotts research into anxiety:
limitations

Answer 29

P: Evidence from Christianson & Hubinette (1933) suggests anxiety can improve accuracy of EWT
E: out of 58 EW to real robberies, those threatened directly (higher anxiety) were more accurate in recall than onlookers
E: continued to be the case months later
L: contradicts J&S; suggests anxiety may increase accuracy

P: demand characteristics
E: aware they are being studied, act differently
E: may not be actually anxious if they know it’s staged
L: low internal validity as not measuring true behaviour and the findings cant be generalised to real life effects of anxiety

P: ethical issues
E: lack of protection from harm
E: ppts may have expericed fear and distress from believing there had been a crime or felt in danger
L: how’s against ethical code of conduct