The impact of legal expertise on moral decision-making biases

Abstract

Traditional and mainstream legal frameworks conceive law primarily as a purely rational practice, free from affect or intuition. However, substantial evidence indicates that human decision-making depends upon diverse biases. We explored the manifestation of these biases through comparisons among 45 criminal judges, 60 criminal attorneys, and 64 controls. We examined whether these groups' decision-making patterns were influenced by (a) the information on the transgressor's mental state, (b) the use of gruesome language in harm descriptions, and (c) ongoing physiological states. Judges and attorneys were similar to controls in that they overestimated the damage caused by intentional harm relative to accidental harm. However, judges and attorneys were less biased towards punishments and harm severity ratings to accidental harms. Similarly, they were less influenced in their decisions by either language manipulations or physiological arousal. Our findings suggest that specific expertise developed in legal settings can attenuate some pervasive biases in moral decision processes.

Keywords: Psychology; Science, technology and society.

Fig. 1. Examples of stimuli for language manipulation.

The top panel shows a stem scenario depicting intentional harm. The bottom panel presents a stem scenario depicting accidental harm. At the left side of each panel harm is described with gruesome terms, and at the right side harm is described with plain, just-the-facts language. Note that the consequence in each scenario is the same, namely, death.

Fig. 2. Effects of gruesome language (GL) and intentionality on morality, punishment and damage ratings.

a We observed a group-by-language interaction, such that only participants of the control group had significantly higher morality ratings when reading gruesome descriptions of harm, relative to the PL condition. b We also found a group-by-intentionality interaction, revealing that punishment ratings were significantly lower for the judges and attorneys groups in comparison to controls during accidental scenarios. There were no differences between groups when participants read intentional scenarios. c We found a group-by-intentionality interaction, revealing that harm severity ratings were significantly lower for judges and attorneys than controls in accidental scenarios. Participants in all groups assessed harms as significantly greater in magnitude when they were committed intentionally, in comparison to situations when harm was accidentally caused. This reveals a biasing effect of intentionality on damage assessments, because the accidental and intentional conditions contained an equivalent range of harms. Significance coding: *p < 0.01; **p < 0.001; ***p < 0.0001.

Fig. 3. Association between mean morality ratings and emotional activation as indexed by the percentage change of power in the low frequency (LF) band.

There was a significant correlation between LF power and mean morality ratings only for control participants that read gruesome descriptions of harm, but not for those that read plain descriptions. a This association was not significant in attorneys b or judges c who read either plain or gruesome descriptions. Depicted in the scatter plots are the regression lines and 95% confidence intervals.