A mixed-methods analysis of the influence of bio-behavioral scientific evidence on U.S. judges' reasoning and sentencing decision-making

In contemporary criminal justice systems, the integration of neuroscience evidence into legal proceedings poses complex challenges as well as opportunities. This study investigates how judges–shaped by their beliefs and personal characteristics–approach sentencing decision-making in light of scientific explanations of behavior or psychiatric diagnoses. Specifically, it addresses two research questions: (1) How do scientific explanations of behavior influence how judges assess responsibility? (2) What cognitive biases or misconceptions may affect their interpretations of such evidence? We utilized a mixed-methods approach, including Natural Language Processing techniques and qualitative analysis, to analyze data from semi-structured interviews with 34 U.S. criminal court judges. Sentiment analysis revealed differences in emotional tone between judges with varying degrees of belief in scientific determinism and based on gender, age, geographical region, and professional background. Structural Topic Modeling identified key considerations, including determinism, responsibility, treatment needs, and moral concerns. Qualitative analysis enriched these results by unraveling the philosophical and legal considerations that judges grapple with when considering scientific explanations for defendants' behavior. Findings underscore the nuanced interplay between scientific understandings of behavior, personal beliefs, and judicial decision-making.