Reaching A Verdict - Persuading A Jury

Question 1

Results Pennington and Hastie 1

% of guilty verdicts

Answer 1

PRESENTING INFO IN SO MORE PERSUASIVE THAN WO.
Prosecution SO… Defence WO = 78%
Prosecution WO… Defence SO = 31%
There is a large difference in % guilty, the difference is presentation evidence. It is clear different order effects % guilty, this shows Story Order has a greater influencing effect than Witness Order.

Primacy and recency effect controlled for, hence confident they have shown the persuasive effect of story order.

Question 2

Results Pennington and Hastie 2

Answer 2

No control, therefore no comparison. Natural control as closest to real life environment would be PWO… DWO 63% guilty verdict when ecologically valid. Hence comparing 59% guilty could say PSO… DSO was reliable result as similar to “natural control” condition.

Question 3

Results Pennington and Hastie 3

Answer 3

Stories made by witnesses are influence by their own world experience.

Question 4

Results Pennington and Hastie 4

Answer 4

The story the juror constructs DETERMINES the jurors decisions.

Question 5

Results Pennington and Hastie 5

Answer 5

Subjects expressed greater confidence in their verdicts of story order.
Confidence is rated on a 5 point scale.

Question 6

Effect of order of testimony

Answer 6

• Primary effect + Recency effect

- Arousal level at start of task

Question 7

Persuasion

Answer 7

What happens when expert psychologist gives evidence about research into psychological variables affecting eyewitness account?

• Weapons effect
• Delays effect

Jury should treat testimony with some care as witnesses likely to inaccurate or reconstructed version of events.

Question 8

Procedure Cutler

Answer 8

Expert psychological testimony affects jurors decision making?
Lab experiment with video mock trail.
Questionnaire

Question 9

DV Cutler

Answer 9

• Verdict
• Memory test
• Rating scales

Question 10

IV Cutler

Answer 10

• Witnessing Identifying Conditions eg. delay in identification, suggestive instructions or vice versa
• Witness confidence of identification of robber
• Form of testimony - qualitative or quantitative
• Expert opinion of likelihood to be correct on scale of 1-25

Question 11

Results of Juror verdicts

Answer 11

When identifying conditions good, more guilty verdicts were given. This increased if form of testimony was descriptive. All other variables insignificant.

Question 12

Results of Juror memory

Answer 12

85% correctly recalled testimony therefore memory cannot be blamed for lack of effect on jurors judgements.
Memory of what expert said (4 stages of memory) greater than 50%, 81% recalled at least one stage.
Recalled what expert had said about weapons effect, disguise in displays and delays in identification.

Question 13

Results juror confidence

Answer 13

Good Witness identifying conditions (no disguise, hidden gun, short delay in identification, no suggestive information) that there was more confidence in identification.
Effect was stronger if they had heard the expert witness and if the witness confidence was 100% confident of identifying the correct robber, rather then 80%.

Question 14

Conclusions Cutler

Answer 14

1: Expert testimony improved jurors knowledge and made them may more attention to WIC.
2: Expert testimony decreased reliance on witness confidence alone (80% or 100%)
3: No evidence that expert testimony made witness sceptical about witness credibility or accuracy of identification.
4: With expert testimony, juror sensitivity to problems with evidence improved and may prevent miscarriages of justice.

Question 15

Lotus EX1 results

Answer 15

Expert testimony reduced % guilty verdict 39%, compared to 58%.
Fewer guilty verdicts for non-violent 41% to violent 56%
Expert testimony led to reduction of guilty verdict in non violent 12%, compared to 25% in violent.