The social sciences have developed dramatically over the last century in both breadth and sophistication. These disciplines offer systematic data collection and an analytic methodology to test our empirical intuitions about individual behavior and social institutions. Prior to the development of the social sciences and their application to the legal system, judges could rely only on their personal experiences and untested empirical intuitions when faced with complex questions of social fact. A court’s exclusive reliance on personal experience, however, “could continue only so long as its ‘best guesses’ about [empirical] facts were as good as . . . everyone else’s.” Today, social science research exists on a wide range of legal issues, and courts are faced with the challenge of resolving controversial questions of empirical fact on the basis of complex and sometimes conflicting scientific literatures. Courts have, for example, reviewed social science evidence on racial segregation, maximum work hours, First Amendment rights, jury size, the exclusionary rule, eyewitness identification, and child custody. Yet, despite efforts to encourage the integration of social science into the judicial process, and despite a modest increase in judicial reliance on social science evidence in recent decades, courts remain reluctant to incorporate social science into their decisionmaking.
In this Comment, I explore the role of social science in the development of common law precedent. I begin with the assumption that most judges and legal scholars today would support the use of social science in particular judicial decisions where the research findings are valid, replicated, consistent across studies, and directly applicable to the legal question at hand. I focus instead on the problem of suboptimal social science. In the vast majority of cases only suboptimal evidence is available—that is, evidence that is valuable but not completely valid, consistent, or directly appli¬cable. Judges and legal scholars have long debated the benefits and disadvantages of using this kind of limited empirical research in judicial decisionmaking. And litigants frequently argue that courts should not rely upon specific social science evidence because of limitations in the literature. Yet courts are given relatively little guidance on how to address suboptimal social science in the development of precedent.