Effect of Order of Testimony – Pennington and Hast
Aim: To test the hypothesis that jurors are more easily persuaded by story order than witness order.
Participants: 130 Students from Northwestern Uni and Chicago. Half were put in the story order condition, half in witness order condition.
Procedure: Listened to stimulus trial + answered questions on verdict + confidence
Results: Story order had greatest confidence in defence and prosecution. Witness order was least effective.
Conclusion: Story order has a persuasive effect.
Persuasion - Cutler
Aim: To investigate the effect of expert witnesses challenging eye witness memory on jury decision making.
Participants: 538 psychology undergraduates.
Procedure: Watched video taped mock trial of expert witness talking about good Witness identification conditions, confidence, statistics of identification and personal opinion. Participants then completed a questionnaire independently.
Results: Memory was fine - 85% recalled the testimony. When WIC were good, more guilty verdicts and this increased if expert witness gave a descriptive testimony. Jury had more confidence in accuracy of eyewitness in good WIC, if the witness was more confident and if they heard expert witness.
Conclusion: Improved jurors knowledge and sensitivity to prevent miscarriages of justice. Shows effect of expert witness.
Effects of Evidence Being Ruled Inadmissible - Bro
Aim: To examine the effect of information being ruled inadmissible by a judge.
Participants: Actual jurors on service that agreed to serve on an mock trial.
Procedure: Participants listened to tapes of evidence from previous trials and were then asked to deliberate as if they were hearing the case.
Results: Jurors awarded the victim on average $37,000, $4000 more than when the defendant didn't have insurance ($34,000) which suggests juries make larger awards to victims when the insurance company will have to pay. If the judge ruled the fact the defendant has insurance inadmissible the average increased to $46,000 .
Conclusion: When jurors are told they must disregarded the information, they pay more attention to it.
Witness Appeal – Castellow
Aim: To see if attractive defendants will be less guilty and vice versa.
Participants: 71 Male and 74 female psychology students at East Carolina University.
Procedure: Shown pictures and given case, asked 'do you think Mr Radford is guilty of sexual harassment?' and had to rate defendant and victim on bipolar scales such as dull-exciting, warm-cold.
Results: Physically attractive defendants and victims were rated positively on other personality variables. Attractive defendants were found guilty 56% of the time compared to unattractive at 76%. Attractive Victims made guilty verdict 77% of time compared to 55% for unattractive. Both sexes equally influenced by appearance.
Conclusion: Appearance has a powerful effect; defendants should dress up.
Witness Confidence – Penrod and Cutler
Aim: To examine several factors: mainly confidence in which jurors consider when evaluating eyewitness identification evidence.
Participants: Undergrads, eligible and experience jurors.
Procedure: Shown videotaped mock trial, witness testified 80% or 100% confidence in identification
Results: Witness confidence was only variable to show statistical difference. 100% confidence had 67% convictions whereas 80% confidence has 60% convictions.
Conclusions: Witness confidence affects jury decision.
Effects of Shields and Videotapes on Children Givi
Aims: To see if shields and videotaped testimony increased guilty verdicts and to see if these protective devices affect credibility of either prosecution or defence.
Participants: 150 male and 150 female psychology students white and middle class.
Procedure: Watched 2 hour film of case into sexual abuse, there were three versions (open court, shield and video) They then gave their verdicts and rated credibility of child witness and defendant.
Results: No significant differences between conditions, but more females than male found the defendant guilty (58.6% vs 38.6%). Females rated defendant less credible and victim more credible. Second experiment showed when tape stopped after child testified, open room condition participants more likely to convict.
Conclusion: Shows that gender differences involved in child cases, but defendant not more at risk if protective devices are used.
Stages in Decision Making - Hastie
Orientation period: Relaxed and open discussion, set agenda, raise questions and explore facts, different opinions arise.
Open confrontation: Fierce debate, focus on detail, explore different interpretations, pressure on minority to conform, support for group decision.
Reconciliation: Attempts to smooth over conflict, tension released by humour
The opinions of the majority are extremely influential in the final decisions made within a group If the first decision favoured acquittal then in 86% of cases a not guilty verdict was returned and vice versa with 90% guilty verdict.
Majority Influence – Asch
Aim: To investigate the effects of conformity to a majority when the task unambiguous
Participants: 123 American male undergraduates.
Procedures: Had to match a line to correct one, confederates purposely gave wrong answer on critical trials.
Results: 32% conformity (gave wrong answer). No one conformed all the time, 25% didn't conform once.
Conclusion: Shows impact of majority, but there are individual differences.
They conformed due to:
- Distortion of perception - thought they were right.
- Distortion of judgement - doubt in accuracy so yielded to majority.
- Distortion of action - Didn't want to be ridiculed so went with group.
Minority Influence – Nemeth and Wachtler
Aim: To investigate the influence of perceived autonomy (choosing where to sit at a table) and consistency on minority influence.
Participants: Groups of 5 (one stooge) drawn from an adult sample of students.
Procedure: Group have to deliberate on amount of compensation due for victim of injury. After hearing facts, make individual verdict, taken to a rectangular table 2 seats on long ends and one at the head. In some groups participants chose where to sit, with the stooge at the head of the table, other groups told where to sit . They then deliberate, the stooge adopts deviant position suggesting $3000 instead of $10000-25000.
Results: The stooge exerts influence when consistent and when perceived or autonomous because chosen seat. Whereas when experimenter tells everyone where to sit; he has little influence. When he has been influential, effect continues in second case. When he sits at head of table, seen as more consistent and confident.
Conclusions: Interesting repercussions for jury where people sit. Many examples exist where minorities have influenced i.e. gay rights, global warming, cult music. Possible that in jury room this effect weakened by need for unanimity in a limited time.