Pairs (N=234) of witnesses and lineup administrators completed an identification task in which administrator knowledge, lineup presentation, instruction bias, and target presence were manipulated. Administrator knowledge had the greatest effect on identifications of the suspect for simultaneous photospreads paired with biased instructions, with single-blind administrations increasing identifications of the suspect. When biased instructions were given, single-blind administrations produced fewer foil identifications than double-blind administrations. Administrators exhibited a greater proportion of biasing behaviors during single-blind administrations than during double-blind administrations. The diagnosticity of identifications of the suspect in double-blind administrations was double their diagnosticity in single-blind administrations. These results suggest that when biasing factors are present to increase a witness's propensity to guess, single-blind administrator behavior influences witnesses to identify the suspect.

Innocent suspects may not adequately protect themselves during interrogation because they fail to fully appreciate the danger of the situation. This experiment tested whether innocent suspects experience less stress during interrogation than guilty suspects, and whether refusing to confess expends physiologic resources. After experimentally manipulating innocence and guilt, 132 participants were accused and interrogated for misconduct, and then pressured to confess. Systolic and diastolic blood pressure (SBP, DBP), heart rate (HR), respiratory sinus arrhythmia (RSA), and preejection period (PEP) responses quantified stress reactions. As hypothesized, the innocent evidenced smaller stress responses to interrogation for SBP, DBP, HR, and RSA than did the guilty. Furthermore, innocents who refused to confess exhibited greater sympathetic nervous system activation, as evidenced by shorter PEPs, than did innocent or guilty confessors. These findings suggest that innocent suspects underestimate the threat of interrogation and that resisting pressures to confess can diminish suspects' physiologic resources and lead to false confessions.

Drawing on the psychological principle that proximal consequences influence behavior more strongly than distal consequences, the authors tested the hypothesis that criminal suspects exhibit a short-sightedness during police interrogation that increases their risk for confession. Consistent with this hypothesis, Experiment 1 showed that participants (N = 81) altered how frequently they admitted to criminal and unethical behaviors during an interview to avoid a proximal consequence even though doing so increased their risk of incurring a distal consequence. Experiment 2 (N = 143) yielded the same pattern, but with a procedure that reversed the order of the proximal and distal consequences, thereby ruling out the possibility that it was the unique characteristics of the consequences rather than their proximity that influenced the admission rate. The authors discuss the supported psychological process as a potential explanation for several well-established findings reported in the literature on confessions.

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