Narcissism is a dynamic form of personality characterized by a pervasive sense of grandiosity and self-importance, and by a need to obtain continuous self-validation from others. Very little is known about its etiology and development. What factors (e.g., temperament, parenting experiences) and processes (e.g., transactions between these factors over time) cause some children to become more narcissistic than others? When does narcissism first emerge, and how does narcissism develop over time? This article describes a framework for research on the etiology and development of narcissism, and recommends ten research priorities. This research should yield fundamental knowledge and should inform intervention efforts to minimize the negative impact narcissistic individuals have on themselves and on others. © 2009 Cambridge University Press.