UC Berkeley

In this dissertation I examine a form of deception that I refer to as certainty posing, or exaggerating one’s degree of certainty. People are often expected to convey certainty in their ability to know the truth or forecast the future. As I argue, this expectation can motivate them to deliberately exaggerate their degree of certainty. In the first chapter of this dissertation, I find support for this assertion across a series of six experiments. Specifically, I find evidence that certainty posing is motivated by impression management concerns to appear knowledgeable and credible—particularly in situations where people can attribute uncertainty to inadequate knowledge. Additionally, I document that this behavior has the potential to bias consumers of advice. In the second chapter of this dissertation, I consider the moral acceptability of certainty posing and argue that people should perceive it as more morally acceptable than other forms of deception documented in the literature. I find limited evidence for this proposition: While certainty posing is perceived as more morally acceptable than blatant deception (telling the polar opposite of the truth), it is not perceived as any more acceptable than feigning uncertainty. Overall, this research makes two primary contributions to the literature. First, it documents that impression management motives can cause people to engage in strategic displays of overconfidence. Second, it establishes that individuals’ motivation to engage in these displays is largely determined by the source to which they can attribute their uncertainty.