The present analysis addresses a question with a rich tradition in social psychology: the effects of expectancies on behavior. More specifically, the current research is devoted to the analysis of critical boundary conditions that determine the impact of positive and negative performance expectancies on the cognitive test performance of test takers in performance situations. The central hypothesis of the present research claims that the mode of self-regulation, that is, whether a person is in a state of eagerness and directed at approaching positive outcomes or in a state of vigilance and directed at avoiding negative outcomes, is a crucial moderating factor that determines the impact of positive and negative expectancies on performance. The analysis presented in this contribution tries to accomplish three main goals: (1) to develop a general theoretical framework that is designed to explain differential effects of positive and negative performance expectations on test performance and emphasizes the role of strategic motivational mechanisms of self-regulation; (2) to challenge the unidirectional perspective proposed by stereo-type threat theory (Steele, 1997) with respect to the consequences of negative stereotypic performance expectations by specifying conditions under which “classic” stereotype threat effects emerge and constellations that eliminate or even reverse this pattern; and (3) to test whether specific motivational mechanisms are affected by performance expectancies. The findings of six experimental studies support the basic assumptions as proposed in the new theoretical framework. Implications of the theoretical model as well as possible applications in everyday settings are discussed.