ABSTRACT The social concepts of optimism, pessimism, and realism were investigated by assessing the prototypical acts (thoughts, feelings, goals, and actions) that laypersons assign to optimists, pessimists, and realists responding to a controllable and an uncontrollable situation. Optimists and realists, but not pessimists, were seen as adjusting their behavior to the situation. However, whereas optimists were characterized by flexibility in thoughts and feelings but invariance in goals and actions (i.e., they pursued their goals in both controllable and uncontrollable situations), the act profiles assigned to realists varied on all of these dimensions. The profile assigned to pessimists was characterized by cognitive, affective, motivational, and behavioral invariance, encompassing negative construals of the situation, giving up, and a focus on distress.