Evaluating the impact of first-yes-counts instructions on eyewitness performance using the two-high threshold...

Area of Science:

• Psychology
• Forensic Science

Background:

• Eyewitness research often uses "first-yes-counts" instructions in sequential lineups, where only the initial identification decision is considered.
• These instructions conflict with standard police protocols that allow witnesses to view the entire lineup.
• This discrepancy raises questions about the ecological validity of current eyewitness identification research.

Purpose of the Study:

• To experimentally investigate the impact of "first-yes-counts" instructions on eyewitness identification decisions.
• To analyze how these instructions affect the detection and guessing processes within the two-high threshold eyewitness identification model.
• To assess the ecological validity of sequential lineup research protocols.

Main Methods:

• Reanalysis of existing data from Horry et al. (2012).
• Conducting a conceptual replication of the Horry et al. study.
• Utilizing the two-high threshold eyewitness identification model to differentiate decision-making components.

Main Results:

• "First-yes-counts" instructions did not significantly alter the detection of the actual culprit.
• These instructions were found to decrease the likelihood of guessing-based selections in identification tasks.
• Both the data reanalysis and the replication confirmed these findings.

Conclusions:

• "First-yes-counts" instructions in sequential lineups do not impair the ability to detect a culprit.
• These instructions reduce the rate of erroneous, guessing-based identifications.
• To enhance the real-world applicability of sequential lineup research, the use of "first-yes-counts" instructions should be discontinued.