The misjudgment of criminal responsibility

Generally, a criminal statute must consist of two essential elements: a description of the forbidden act (actus reus) and a designation of a guilty mental state (mens rea). For a crime to be committed, an individual must commit the forbidden act with the culpable mental state. For any criminal act, both criminal liability and the possible punishment turn largely on retrospective judgments by legal decision-makers about what a defendant was or was not thinking at the time of committing the forbidden act. Given the central and foundational nature of this legal judgment, there is surprisingly little empirical study of how the mens rea construct functions. Shen and colleagues have studied the reliability of mock jurors' ability to distinguish between the various mental state categories defined in the Model Penal Code and have identified some support for jurors' ability to reliably sort "guilty minds" into their "correct" categories (Shen, Hoffman, Jones, Greene, & Marois, ). The present study builds on this work by examining mock jurors' ability to reliably and "accurately" judge a defendant's mens rea at the time of an offense under conditions reflecting how criminal jurors are tasked with judging a defendant's mens rea. It was hypothesized that folk psychology models of human behavior that generally presume a high degree of personal control and responsibility would bias individuals' judgments of others' criminal behavior in the direction of reflecting intentional and purposeful conduct. Overall, results demonstrate that, in a surprisingly high percentage of cases across many conditions, individual decision-makers are indeed likely to attribute the most culpable mental state (purpose) to defendants, even when the facts on the record are judged by legal experts to depict no more than negligent or reckless conduct.