Academics frequently serve as expert witnesses in legal cases, yet their role as transmitters of social scientific knowledge remains under-examined. The present study analyzes the deployment of social science within British Columbia's polygamy reference trial where research is used to support the assertion that polygamy is inherently harmful to society. Within the trial record and the written decision, the protection of monogamy as an institution is performed in part through the marginalization of qualitative methodology and the concurrent privileging of quantitative studies that purportedly demonstrate widespread social harms associated with the practice of polygyny.