Context Effects on Diagnostic Judgments Among Master's Students in Forensic Psychology

Forensic psychologists are required to perform clinical evaluations on defendants with a variety of instruments to decide on a criminal responsibility judgment, yet the process of diagnostic decision-making may be vulnerable to cognitive biases. This study examined whether the framing and timing of the forensic information influence diagnostic and legal responsibility judgments made by master’s students. A Latin square counterbalanced between-subjects design was implemented. Ninety participants were randomly assigned to one of three conditions (Clinical Only, Forensic at Beginning, Forensic at End) and asked to evaluate three case vignettes. Diagnostic accuracy and confidence were assessed as exploratory analyses across conditions, and consistency of diagnostic judgment across time points was examined using Cohen’s kappa. The distribution of diagnostic responses showed no statistically significant evidence of an effect across forensic information conditions for any of the three cases (Hypothesis 1). Cohen’s kappa values revealed fair to moderate above-chance agreement between pre- and post-forensic diagnoses, indicating no statistically significant change in diagnostic judgments (Hypothesis 2). No statistically significant difference in criminal responsibility judgments was found between the Forensic at Beginning and Forensic at End conditions for any of the three cases (Hypothesis 3). Exploratory analyses further revealed no statistically significant differences in diagnostic accuracy or confidence ratings across conditions. The findings can be explained by the small sample size and all participants being students. Unlike experts, students do not have previous field experiences, which might make them less susceptible to base-rate expectations, adversarial allegiance, and confirmation bias. Low confidence ratings across conditions and time points are supportive of this explanation. Future research comparing trainees and experienced practitioners with larger samples is needed to clarify the role of expertise in susceptibility to cognitive bias.