Factors Affecting Eyewitness Testimony: Misleading Information
This page examines how misleading information, particularly through leading questions and post-event discussions, can impact the accuracy of eyewitness testimony. It presents key research findings and evaluates their implications and limitations.
Definition: Misleading information refers to incorrect information given to an eyewitness, usually after the event has occurred.
Research on Leading Questions
Loftus and Palmer 1974 conducted a seminal study on the effects of leading questions:
- 45 students watched film clips of car accidents and were asked questions about them
- The critical question varied the verb used: "About how fast were the cars going when they hit/smashed/collided/bumped/contacted each other?"
- Findings showed that the verb used influenced speed estimates, with "smashed" resulting in the highest mean estimate 40.5mph and "contacted" the lowest 31.8mph
Highlight: This study demonstrated that the wording of questions can significantly bias eyewitness recall of events.
Two explanations are proposed for this effect:
- Response-bias explanation: The wording only influences how participants choose to answer, not their actual memory
- Substitution explanation: The wording of the leading question actually changes participants' memory of the event
A follow-up experiment by Loftus and Palmer supported the substitution explanation, as participants who heard "smashed" were more likely to falsely report seeing broken glass.
Research on Post-Event Discussion
Gabbert et al. 2003 investigated the impact of post-event discussions:
- Participants in pairs watched videos of the same crime from different viewpoints
- They discussed what they had seen before individually completing a recall test
- 71% of participants mistakenly recalled aspects they hadn't actually seen, compared to 0% in a control group without discussion
Highlight: This study provides strong evidence for memory conformity, where witnesses incorporate information from others into their own memories.
Explanations for Post-Event Discussion Effects
- Memory contamination: Eyewitnesses combine misinformation from others with their own memories
- Memory conformity: Witnesses go along with each other for social approval or believing others are correct
Evaluation of Research
Strengths:
- Real-world applications in the criminal justice system
- Informs police interviewing techniques and use of expert witnesses in trials
Limitations:
- Artificial lab settings may not reflect real-world eyewitness experiences
- Potential demand characteristics in studies
- Central details may be more resistant to misleading information Sutherland & Hayne, 2001
- Some evidence challenges the extent of memory conformity Skagerberg & Wright, 2008
Example: In real-life situations, eyewitnesses may be more motivated to be accurate than research participants, potentially making their testimony more dependable than lab studies suggest.
This research highlights the importance of careful questioning techniques and the potential risks of witness contamination through post-event discussions in criminal investigations and legal proceedings.
