It is popularly believed that powerful people enjoy a nearly-absolute lack of constraints, and that powerless people suffer under overwhelming constraints; in fact, such differences largely define the social categories of ‘powerful person’ and ‘powerless person.’ This association of power-related social categories and constraint constitutes a stereotype that may lead perceivers to overlook other, more diagnostic information when explaining others' behavior. As a result, the actions of powerholders may tend to be seen as dispositionally motivated and those of the powerless as situationally motivated. This should occur because of both real differences in constraint, and bias in the failure to account for other, more diagnostic information about constraint. Two studies support these predictions. In Study 1, participants judged powerless workers as more situationally motivated, especially under coercion, than both controls and powerholders, who were judged as more dispositional. In Study 2, given more fine-grained information about constraints and power, participants' attributions reflected both accurate use of this information and bias. Copyright © 2006 John Wiley & Sons, Ltd.