While the legal practice of oath taking is foundational to the United States court system, to our knowledge only one empirical study has examined the effect of oath taking on the truthful disclosure of adults questioned about recent dishonest behavior. This study found that the oath does, in fact, increase truthful disclosure, but does not fully investigate the mechanisms by which the oath influences disclosure. The proposed project expands on Joseph et al. by addressing limitations of the original design while simultaneously investigating the role of language in the oath’s influence. In other words, is the driving influence of the oath derived from the solemnity of the language or the explicit commitment to engage in honest behavior? Further, this project investigates the mechanisms by which the oath influences truthful disclosure by examining the interaction of the oath and motivation to be perceived as innocent. In addition, ethical dissonance—psychological discomfort arising from dishonest behavior that challenges the individual’s moral self-image—is investigated as a mediating variable. Specifically, swearing to tell the truth may increase ethical dissonance, and telling the truth when questioned about the dishonest behavior may serve as a method of dissonance reduction.
When experiencing psychological distress resulting from cognitive dissonance, individuals engage in the first method of dissonance reduction provided. Expanding on the theory of ethical dissonance, this project uses a laboratory setting to test ethical dissonance in a legal setting as a form of dissonance reduction mirroring testifying in court: swearing to tell the truth prior to providing a statement about an activity where the participant may have engaged in dishonest behavior. What little research exists examining the influence of the oath on subsequent truthful disclosure predominately focuses on child testimony. This project expands on the singular examination of the oath’s influence on subsequent truthful disclosure of adults by capturing variables that may influence the severity of ethical dissonance and rate of truthful disclosure in legal settings: strength of the oath and motivation to be perceived as innocent. Moreover, the studies described below investigate the efficacy of an integral, yet relatively unexamined, part of United States trial systems.
	Data collection for this project will occur in a large, Northeastern city, so the adult, community participants will be from a diverse, urban environment: 33% White, 29% Hispanic, 23% Black, 13% Asian. The use of the multi-ethnic, multi-cultural community population provides an opportunity to examine the research question in underrepresented populations who are overrepresented in the criminal justice system. Further, the student base at the host institution is culturally and ethnically diverse: 37% Hispanic, 28% White, 21% Black, 11% Asian. Additionally, 57% of the student base is female. The research team will be comprised of members of the minority-majority student base at the host institution, thereby giving underrepresented groups an opportunity to be involved in the development and execution of academic research. 
Although the research is driven by theory, the practical implications are important for the legal system. Understanding both the conditions under which witnesses are likely to provide truthful testimony, as well as why witnesses provide truthful testimony, is central for several groups of legal professionals, including defense attorneys, prosecutors and judges.
