Forensic Confirmation Bias: Do Jurors Discount Examiners Who Were Exposed to Task-Irrelevant Information?*^{, †}

Area of Science:

• Cognitive Psychology
• Forensic Science
• Legal Psychology

Background:

• Task-irrelevant information can bias forensic science evidence, reducing its probative value through forensic confirmation bias.
• Understanding how laypeople perceive examiner bias is critical for ensuring fair legal judgments.

Purpose of the Study:

• To investigate whether laypeople discount forensic examiner opinions when aware of potential biasing information (e.g., a defendant's confession).
• To examine laypeople's trust in examiners who admit or deny vulnerability to bias.

Main Methods:

• Three experiments involving 765 lay participants evaluating trial summaries.
• Participants read summaries with testimony from forensic examiners with varying awareness of biasing information and varying admissions of potential influence.

Main Results:

• Laypeople discounted testimony from examiners who admitted potential bias due to a confession.
• Laypeople trusted examiners who denied bias, even if aware of the confession, as much as unbiased examiners.
• Participants generally failed to recognize the value of context-blind forensic judgments.

Conclusions:

• Laypeople tend to believe examiners who claim to be impervious to bias, rather than recognizing the benefit of context-blind assessments.
• Findings underscore the importance of context management procedures in forensic laboratories to avoid misleading legal fact-finders.