The role of expertise, personality traits and decision-making styles in criminal case evaluation: a comparison among judges, law students and non-legal professionals

Purpose The decision-making process represents the optimal mechanism for evaluating criminal acts. Consequently, it is essential to ascertain whether external factors may potentially influence the evaluation process. The purpose of this study is to identify the factors that are most likely to influence the decision-making process, with a particular focus on the role of personality styles in shaping perceptions of punishment and the outrageousness of criminal acts. Design/methodology/approach This research project focused on the assessment of two distinct types of (mock) criminal acts: domestic violence and an act of negligence perpetrated by a pharmaceutical company. The crime assessment was conducted by three distinct groups, differentiated according to their level of expertise: law students, students from other professions and judges. Additionally, it explored the potential influence of an individual’s personality or decision-making style on the evaluation of criminal acts. The objective of this study is to identify the factors that are most likely to influence the decision-making process, with a particular focus on the role of personality styles in shaping perceptions of punishment and the outrageousness of criminal acts. Findings The results of this study demonstrated that there are disparate evaluations of crime contingent on the group to which one belongs. The personality trait that exhibited the most robust correlation was Machiavellianism. Indeed, as this tendency became more prevalent, so did the assignment of punishment and the perceived outrageousness of the offense. No correlation was found between a more intuitive or more reflective decision-making style. In conclusion, it can be stated that, when all the factors analysed are taken into account, the decision-making process is subject to influences. Research limitations/implications The limited number of judges (n = 18) reduces the generalizability of findings on expertise effects. While including real judges is innovative, future studies could benefit from larger and more balanced samples. This study examines only domestic violence and corporate negligence, which restricts the applicability of results to other criminal contexts. Future research could explore a broader range of cases. Practical implications Legal education and experience lead to more consistent and balanced case evaluations, emphasising the value of professional training in the judicial system. Personality traits influence decision-making, suggesting the potential for incorporating personality-awareness training into judicial education programs. The role of moral disengagement in punishment decisions highlights the need to consider psychological factors in judicial decision-making. This aligns with recent research on the interplay of personality, morality and decision-making in forensic contexts. Originality/value This paper is particularly valuable, as it illustrates the relationship between decision-making styles and personality in the perception of crime. One of its key strengths lies in the inclusion of a sample of real judges, a rarity in the literature because of the inherent challenges of accessing this professional group. This innovative approach enhances the study’s relevance and sets it apart from many studies that rely on mock or hypothetical participants. Moreover, by examining critical variables such as personality traits and decision-making processes, this paper offers meaningful insights into their interplay in judicial contexts.