Contaminated Confessions: How Source and Consistency of Confession Details Influence Memory and Attributions

Abstract

Via “contamination,” false confessions usually contain accurate and nonpublic details, and details that are inconsistent with the case facts ( Garrett, 2010 ). In two studies (N1 = 476; N2 = 364), we replicated previous findings that inconsistent confessions yield fewer guilty verdicts than accurate confessions ( Henderson and Levett, 2016 , Palmer et al., 2016 ). The source of the details in a confession (interrogator vs. suspect) also influenced guilt decisions: when details were introduced by the suspect, participants were more confident in his guilt than when the interrogator introduced the details. Exploratory analyses revealed that although consistency and source of confession details affected memory for crime facts, memory did not influence verdict decisions as much as participants’ causal attributions for the confession. Consistency and source influenced whether participants attributed the confession to the suspect's guilt or something other than guilt (e.g., coercion), which in turn affected guilt judgments and confidence.