Being epistemically responsible requires an appreciation for both the power and the limitations of human knowledge, forming and adjusting one’s beliefs in a way that is responsive to the right criteria. Epistemic responsibility is needed among the populace as well as the elite for a functional democracy. It is also crucial for the understanding of science. However, without clear, shared norms of how best to form, adjust, and justify beliefs, we cannot hold each other epistemically accountable. In this dissertation, I explore how adolescents and adults conceive of the best practices for forming beliefs. Chapter 1 asks what criteria for belief people take as legitimate, and how that affects their scientific beliefs. Chapter 2 examines epistem...