Positivity theory posits that the courts rely on powerful legitimising symbols—such as elaborate judicial attire, honorific forms of address and imposing courtroom design—to ensure legitimacy in the eyes of the public in the absence of an electoral mandate. The argument is that such legitimising symbols evoke images of learning and pageantry and create the presumption that the process by which the decision was made was fair. Typically, positivity theory has been tested by examining whether people who have a greater awareness or knowledge of the courts express higher diffuse support for their decisions. Yet, such an approach assumes that those who know more about the courts will have greater exposure to their legitimising symbols. It does not directly test if exposure to the courts’ legitimising symbols causes people to be more acquiescent with decisions with which they disagree. In this article we use a survey-based experiment to examine if exposure to the legitimising symbols of the High Court makes people more willing to accept decisions of the Court with which they disagree. We assess whether the decision of the High Court Justices to simplify their attire, including, since 1988, ceasing to wear wigs when sitting on the Bench, has adversely affected the Court’s institutional legitimacy by removing some of the mystique associated with the decision-making process. We find that exposure to the Court’s legitimising symbols is associated with higher acquiescence with decisions which people disagree with, but the Court’s decision to simplify the Justices’ attire has not adversely affected diffuse support for its decisions. Our findings are important because the Court is reliant on maintaining legitimacy to enforce the rule of law. Our results speak directly to how the Court can best take steps to increase its institutional legitimacy in the eyes of the public.