Psychology of the Courtroom

Topics Covered:
- How jurors make decisions
- Assessment of evidence
- Biases and preconceptions

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.

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.

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.

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.

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

Composition Rules:
- No specific qualifications for jurors beyond age and voting rights.
Decision Impact: Jurors may assert opinions contradictory to evidence due to nullification.

Initial consistency is often maintained throughout trials; leniency bias may arise during deliberation.
Majority Influence: Majority jurors have significant sway on overall verdict outcomes.

Influence Types:
1. Normative influence: Seeking social acceptance.
2. Informational influence: Gaining information to reduce uncertainty.

Behavioural Styles: Key characteristics necessary for a lone juror’s influence include:
- Consistency
- Flexibility
- Relevance

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.

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

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.