A within-statement baseline comparison for detecting lies.

Area of Science:

• Psychology
• Forensic Science

Background:

• Practitioners often use baselining, comparing a statement to a known truthful one, to judge veracity.
• The effectiveness of within-statement verbal baselining for enhancing accuracy in veracity judgments is not well understood.

Purpose of the Study:

• To investigate if a within-statement verbal baseline comparison enhances discriminatory accuracy in veracity judgments.
• To determine if instructing participants to use surrounding truthful elements as a baseline improves credibility assessments.

Main Methods:

• Participants (n=148) evaluated the veracity of a critical two-hour period within a mock suspect's alibi statement.
• The critical element was either truthful or deceptive, embedded within an otherwise truthful narrative.
• Half the participants received instructions to use the truthful parts of the statement as an internal baseline.

Main Results:

• Instructing participants to make a within-statement baseline comparison did not significantly improve the accuracy of credibility assessments.
• The use of internal verbal baselines did not enhance the ability to discriminate between truthful and deceptive statements.

Conclusions:

• Within-statement verbal baselining is not an effective strategy for improving veracity judgments.
• Future research should explore alternative methods for enhancing accuracy in credibility assessments.