	Despite the central role of the oath in the United States court system, to our knowledge, only one study has examined the effects of oath taking on adults’ testimony, but several studies examine the effect of the oath on children’s testimony. Key findings suggest that truth-inductions—eliciting a commitment to be truthful—increase children’s rates of truthful disclosure, and using “child-friendly” language for the induction increases accuracy of reports while simultaneously decreasing concealment and false disclosure. This research suggests that using an appropriate oath or affirmation—depending on an individual’s disposition—may increase the disclosure of truthful testimony. However, the oldest sample in a published study investigating the effect of promising to tell the truth on truthful disclosure included 8-to 16-year-olds. 
	Investigating how to best elicit truthful testimony from children is important when child witnesses are involved in legal proceedings, but the findings from such studies have limited generalizability to adult testimony. The research suggests that taking a child-friendly oath, instead of the adult version of the oath, does influence children’s truthful disclosure. While the leap from a child-friendly promise to tell the truth to an adult swearing to tell the truth is substantial, the research on children along with the research on self-concept maintenance, moral disengagement, and ethical dissonance, provides the foundation upon which to build the proposed research in an attempt to bridge the gap.	
The above studies examined the effect of an explicit promise to engage in honest behavior on truthful disclosure about a transgressive act. However, the generalizability to adult witness testimony is limited as these studies were conducted with maltreated minors using child-friendly truth inductions. In order to address these issues, researchers examined the effect of swearing to tell the truth on adult witness testimony after the adults were induced to cheat. This section provides an overview of, to our knowledge, the first study in the 800 years that the oath has been a part of the trial system to empirically test whether swearing to tell the truth influences adult witness testimony. 
Using a modified version of the Russano, Meissner, Narchet, and Kassin cheating paradigm, researchers tested a paradigm designed to elicit cheating while examining oath taking in legal settings. Upon arriving in the lab the experimenter welcomed participants and directed them to a waiting room where they and another participant—a confederate—received informed consent. The two participants were then directed to the test room, received task instructions, and given fifteen minutes to complete a thinking task testing factual knowledge and problem-solving skills. Participants were reminded during the task instructions, the thinking task, and by the experimenter that the answers should be their own work and collaboration of any kind would constitute cheating. Ten minutes into the thinking task, the confederate asked the participant for an answer to an ambiguously worded question. Participants then self-selected whether to cheat—thereby breaking the rules of the test. After the thinking task, the participant and confederate were separated, presumably for the next part of the experiment. Participants were then randomly assigned to swear to tell the truth—responding in the affirmative when the head researcher asked them to swear to tell the truth, the whole truth, and nothing but the truth—or to a control condition—where no active commitment to moral behavior occurred—prior to giving a statement to the head researcher about what occurred during the course of the experiment.
