Factors Affecting the Accuracy of Eyewitness Testimony: Misleading Information
Verb Intensity and Speed Estimation: Research has shown that changing a single verb in a question (e.g., 'smashed' vs. 'hit') significantly alters a witness's estimation of speed. Stronger verbs lead to higher speed estimates and can even cause witnesses to 'remember' details that never occurred, such as broken glass.
The Co-Witness Effect: When witnesses discuss an event, they often reach a consensus on what happened, even if that consensus is incorrect. This is known as memory conformity, where individuals adopt the accounts of others to gain social approval or because they believe the other person is more accurate.
Source Monitoring Errors: Witnesses often fail to remember where a specific piece of information came from. They may correctly recall a detail but incorrectly attribute it to the original event rather than a subsequent conversation or a leading question.
| Feature | Leading Questions | Post-Event Discussion |
|---|---|---|
| Source | Interviewer/Authority figure | Peers/Other witnesses |
| Mechanism | Suggestive phrasing/Verb choice | Social pressure/Information exchange |
| Primary Effect | Substitution or Response Bias | Memory Contamination or Conformity |
| Context | Formal interrogation/Interview | Informal conversation post-event |
Precision in Terminology: Always distinguish between 'response bias' (changing the answer) and 'substitution' (changing the memory). Examiners often look for these specific terms when you are explaining why misleading information affects accuracy.
Evaluating Research: When discussing studies on EWT, consider the ecological validity. Many studies use film clips in controlled settings, which may not elicit the same emotional response or level of attention as a real-life crime, potentially making real-world memory more or less susceptible to distortion.
Application of Findings: Be prepared to apply these concepts to real-world scenarios, such as how police should conduct interviews. For instance, the 'Cognitive Interview' was developed specifically to minimize the impact of leading questions and post-event discussion.
The 'Video Camera' Fallacy: A common misconception is that human memory works like a recording device that can be replayed perfectly. In reality, memory is a reconstructive process that is active and easily influenced by new information received after the event.
Overstating the Effect: While misleading information is powerful, it does not always overwrite memory. Some research suggests that central, highly salient details of an event are much harder to distort than peripheral, less important details.
Confusing PED with Anxiety: Students often confuse the effects of misleading information with the effects of anxiety on EWT. While both affect accuracy, misleading information is an external cognitive factor, whereas anxiety is an internal emotional state.