Assessing the Viability of Implicit Bias Evidence in Discrimination Cases: An Analysis of the Most Significant Federal Cases

The theory of implicit bias occupies a rapidly growing field of scientific research and legal scholarship. With the advent of tools measuring individuals’ subconscious biases toward people of other races, genders, ages, national origins, religions, and sexual orientations, scholars have rushed to explore the ways in which these biases might affect decision-making and produce broad societal consequences. The question that remains unanswered for scholars, attorneys, and judges is whether evidence of implicit bias and its effects can or should be used in legal proceedings. Although the study of implicit bias dates back several decades, only recently have judicial opinions begun to make direct reference to this body of research. The focus of this Comment is five federal cases that each discussed implicit bias extensively and together represent the most developed legal precedent on the admissibility of implicit bias evidence. Although a small number of other cases also feature extensive discussions of implicit bias, these five cases provide a unique basis for comparison because they are factually and procedurally very similar. All five cases were employment discrimination actions brought under federal law. In four of the five cases, the plaintiffs sought to introduce the testimony of the same expert witness on implicit bias. Therefore, the courts in these cases applied similar substantive and procedural standards to both the plaintiffs’ prima facie cases and to their expert’s proffered testimony. Three of the courts sided with the plaintiffs and treated implicit bias evidence favorably; the other two courts rejected evidence of implicit bias. Because there are only these five cases, it is difficult to draw conclusions from them with certainty. Nevertheless, this Comment considers ways in which implicit bias evidence could be presented to increase the likelihood it will be admitted and to minimize conflict with the unfavorable precedent. It also looks at strategies for admitting implicit bias evidence that have not yet been attempted but are potentially promising