The effect of pre-event instructions on eyewitness identification

Area of Science:

• Psychology
• Cognitive Science

Background:

• Eyewitness identification research often uses simulated crimes and lineups.
• Pre-event instructions, rarely reported, vary in warning participants about the event or task.
• Existing research suggests pre-event instructions can influence eyewitness performance.

Approach:

• This experiment tested the impact of non-specific versus eyewitness pre-event instructions on lineup identification and confidence.
• Participants viewed a simulated crime and completed a lineup.
• Conditions varied based on pre-event instructions: general ("watch this video") or specific ("watch this crime video, you'll complete a lineup later").

Key Points:

• Eyewitness pre-event instructions did not enhance discriminability compared to non-specific instructions.
• Confidence-accuracy calibration remained similar across conditions.
• Participants receiving eyewitness instructions were more likely to label the event a crime and make an identification.

Conclusions:

• Pre-event instructions do not inherently improve eyewitness discriminability in simulated scenarios.
• Specific instructions may bias participants towards perceiving a crime and making an identification.
• Findings have implications for designing eyewitness research and understanding instruction effects on attention and perception.