Psychology of the Courtroom

The Psychology of the Courtroom: Overview

• Topics Covered:

  • How jurors make decisions

  • Assessment of evidence

  • Biases and preconceptions

Part 1: Information Processing

Juror Decision Making

• Decision-Making Models:

  • Various models explain how juries process evidence:

    • Eyewitness Testimony

    • Statistical Evidence

    • Confessions

• Judicial Constraints: Do jurors follow legal standards in civil cases?

• Extra-Evidentiary Influences: Evaluate if non-traditional factors play a role in decision-making actions.

• Defendant Characteristics: Influence of defendant's traits on jurors' decisions.

• Improving Juror Decisions: Ongoing reforms suggested for enhancing decision quality.

Accuracy of Jury Decisions

• Verdict Discrepancies: Judges agree with juries 75% of the time (Kalven & Zeisel, 1966).

  • Notable is the “leniency bias” where judges often overrule jury acquittals to convictions in absentia.

• Social Psychology Influence: Many identified jury phenomena align with broader social psychology traits.

Individual Decision Making Strategies

• Prediction Models:

  • Juror's final verdicts forecasted best by pre-deliberation opinions.

• Mathematical Approaches:

  • Bayesian probabilities (mental meter), algebraic addition, and stochastic-process theories (critical event).

• Explanation-based or cognitive approach

  • Active participant incorporating jurors’ unique experiences, knowledge, beliefs etc affecting how they interpret evidence• Mental representation of information heard

    • Story Model:

      • Jurors build narratives based on trial evidence intertwined with personal experiences and knowledge.

Evaluation of Evidence

• Eyewitness Reliability:

  • Eyewitness testimony leads to higher conviction rates despite influencing factors.

• Hearsay

  • Generally excluded unless special circumstances, e.g. deathbed utterances

  • Studies have found that jurors not influenced by hearsay unless by expert

• Confessions:

  • Often disproportionately affect juror decisions even under duress and inadmissibility.

• Statistical Evidence:

  • Jurors struggle with small versus large samples; yet, they are responsive to statistical weight.

  • Educational pre-instructions can enhance understanding of complex evidence.

Extra-Evidentiary Influences

• Jury Nullification:

  • Jurors can disregard law for moral reasons, creating a ‘community conscience'.

• Trial Prejudices:

  • Prior publicity can affect juror impartiality.

• Defendant Traits:

  • Characteristics like gender, race, and socioeconomic status influence jury perception.

  • Similarity principle

Part 2: Jury Behaviour and Selection

• Jury Composition and selection

• Decision making errors

• Internal group dynamics

Jury Composition and Decision-Making Processes

• Composition Rules:

  • No specific qualifications for jurors beyond age and voting rights.

• Decision Impact: Jurors may assert opinions contradictory to evidence due to nullification.

Decision-Making Stages (Hastie et al, 1983)

1. Orientation Stage: Initial fact exploration.

2. Conflict Phase: Emergence of differing opinions; potentially divisive.

3. Reconciliation: Process of conflict resolution among jurors.

Juror Disagreements

• Initial consistency is often maintained throughout trials; leniency bias may arise during deliberation.

• Majority Influence: Majority jurors have significant sway on overall verdict outcomes.

Psychological Processes in Jury Dynamics

• Influence Types:

  1. Normative influence: Seeking social acceptance.

  2. Informational influence: Gaining information to reduce uncertainty.

Minority Influence

• Behavioural Styles: Key characteristics necessary for a lone juror’s influence include:

  • Consistency

  • Flexibility

  • Relevance

Psychological Biases in Court

• Fundamental Attribution Error: Jurors' judgments are often influenced by dispositional vs situational attributions (Ross, 1977).

• Hindsight Bias: Knowledge of outcomes retroactively reshapes judgments of decision appropriateness.

Juror Selection Processes

• Procedures allow limited juror objections, driving candidate selection based on inferred juror profiles.

Criticism of Jury Research

• Low external validity due to differences in participant demographics and trial settings (Bornstein, 1999).

• Practical implications of research findings are often questioned due to experimental limitations.