Decrements in Miranda abilities: an investigation of situational effects via a mock-crime paradigm

Programmatic research has made important advances during the last decade in understanding how cognitive and psychological variables affect Miranda comprehension and reasoning. However, the effects of situational stressors are largely overlooked in determining the validity of Miranda waivers. As the first systematic investigation, this study uses a 2 × 2 × 2 factorial design on 123 undergraduate participants to examine the effects of being apprehended via a mock crime (i.e., stealing a watch from a Plexiglas case) paradigm on Miranda comprehension and reasoning. Besides the mock-crime condition, the mode of advisement (oral or written) and the length of the warning (124 vs. 228 words) were also investigated. When compared to controls, the mock-crime scenario produced moderate to large effects (ds from .58 to .75) on both Miranda recall and subsequent reasoning. In addition, oral advisements resulted in non-significant trend for decrements in Miranda recall. No main effects were observed for length and no significant interactions were found. Interestingly, specific components (e.g., right to counsel and free legal services) were generally more affected than the more familiar first two components (i.e., right to silence and evidence against you). Within the crime-scenario condition, participants with substantially increased state anxiety predictably performed more poorly than those participants whose state anxiety remained relatively stable. Directions for future research and the implications of these findings on our understanding of Miranda abilities are discussed.