Racial Biases in Polygraphs and Their Legal Implications

Increased attention to racial inequities catalyzed a surge in publications documenting racial biases in neuroscience with one recent article in Nature Neuroscience effectively drawing attention to how skin conductance response is less reliably detected for Black individuals than White. In this correspondence, we introduce pressing additional “real world” concerns in how polygraphs heavily rely on this measure. Despite well-documented issues of validity and reliability with polygraphs, they continue to be used in various stages of the legal system. With Black individuals already facing disproportionate incarceration rates, the reduced reliability for skin conductance used in polygraphs for Black individuals can further exacerbate legal system inequity. Furthermore, these biases accentuate existing challenges interpreting polygraph results given their subjectivity as well as the heightened police-related anxiety reported among Black individuals. We join calls for re-evaluation and possibly exclusion of polygraph evidence in legal settings, considering the amplified risks it poses to Black individuals.