Join | Login


Andrea Miller


Expertise and Bias in Judicial Decision-Making

Andrea Miller, Senior Court Research Associate, National Center for State Courts; Clinical Assistant Professor of Psychology, University of Illinois 

State courts hear about 95% of all legal matters in the U.S. These cases—involving issues like marriage, adoption, evictions, personal injuries, estates, guardianships, and crime—are the ones that intimately affect people’s day-to-day lives and wellbeing. Public interactions with state courts through judges and other court staff, and the decisions that judges make, affect the legitimacy of the justice system, influence life outcomes for individuals and groups, and shape communities. Judges belong to a profession that cares deeply about fairness and justice, and psychologists have an important role to play in helping the courts shape decision-making environments in ways that promote equitable outcomes.  

Unfortunately, the role of expertise in decision-making quality is still not well understood. Although researchers often discuss expertise in ways that equate it with better decision-making, research suggests that the relationship is complex. One the one hand, experts have more domain-specific knowledge than laypeople do, and their knowledge is organized into larger and more interconnected semantic networks. Experts are also better than laypeople at recognizing patterns and identifying acceptable decisions quickly. On the other hand, experts rely more heavily on heuristics than laypeople do, and they tend to choose the first satisfactory course of action that they come across. These findings suggest that there may be some situations in which experts are systematically more vulnerable to biases and errors.  

Previous research using judicial samples has shown that judges often resemble laypeople in their susceptibility to cognitive biases like hindsight bias, the anchoring and adjustment heuristic, and the camera perspective effect. My own research has shown that when it comes to biases with social dimensions, such as race and gender, expertise may not only fail to buffer judges against these biases, but may actually exacerbate them. I found that judges produced larger group disparities in case outcomes than laypeople, and judges with more specialized expertise in particular case types produced larger disparities than judges with less expertise.  

In a recent study presented at the 2021 SPSSI conference, I examine four possible mechanisms for this expertise effect. I find that judges differ significantly from laypeople in their faith in intuition, confidence in their own objectivity, motivation to respond without prejudice, and affective responses to case facts. I’m currently working toward completing a mediation analysis to determine whether each of these group differences explains why judicial expertise is associated with greater race and gender disparities in some case outcomes. In a related project, Julia Spielmann and I are conducting a meta-analysis of expertise in decision-making to identify the features of decision tasks and decision-making environments that correspond to better expert decision-making across professions. I’m also conducting projects that examine the effectiveness of decision-making interventions for judges, as well as the future of joint human-AI decision-making in the courts. It’s crucial that psychologists identify the dispositional and situational factors associated with better expert decision-making, so that we can design decision-making environments that harness the advantages of judges’ and other professionals’ expertise, enhance trust in our most important institutions, and promote equity in society.  

back to menu