Eyewitness Testimony Accuracy

Introduction

Eyewitness testimony can be crucial in court cases.
Focus on factors affecting testimony accuracy: misleading information, post-event discussion, and anxiety.

Bartlett's theory: Memories are reconstructive, not accurate snapshots.
- Schemas: Packages of information that influence memory, leading to errors or confabulations.
Leading Questions: Influence memory recall.
- Substitution bias: Memory changes and replaces old memory.
- Response bias: Emotional pressure alters response without changing memory.
Research: Loftus and Leading Questions
- Study on traffic accidents with varying verbs (hit, smashed, etc.).
- Extreme verbs led to higher speed estimates.
- Follow-up study: More participants reported seeing broken glass when 'smashed' was used, suggesting substitution bias.

Definition: Contamination of testimony with other witnesses' memories.
- Results in memory conformity.
- Research: Gabbert's Study
  - Pairs watched crime from different perspectives.
  - Discussion led to 71% including unseen items.

Definition: Mental state of arousal.
Anxiety can either increase or decrease recall accuracy.
Weapon Focus Effect: Focus on weapon reduces attention to other details (e.g., criminal's face).
Theories:
- Anxiety decreases recall due to distraction.
- Anxiety increases recall by making witnesses alert.
- Yerkes-Dodson Law: Moderate anxiety improves recall; too much anxiety reduces it.
Research: Johnson and Scott Study
- Knife vs. pen scenario, less accurate recall with high anxiety state.
- Supported by field studies (e.g., Peters).
Counter Evidence: Yuille and Cutshall's study of real-life shootings showed high accuracy despite stress.

Real-world applications: Development of cognitive interviews.
Lab studies criticized for low validity and demand characteristics.
- Consequences in real-life testimony are more serious.
- Ethical concerns: Potential harm and lack of informed consent.