Under a mastery learning system students can take successive parallel tests with study interspersed between tests until they demonstrate a minimal level of competency. For most students, such procedures increase final performance, yet some may experience repeated subjective failure. Self-worth theory predicts that repeated failure in the face of prolonged effort expenditure forces students to acknowledge their inability. The negative consequences of repeated subjective failure were examined with 80 undergraduates enrolled in a modified mastery structure psychology course who perceived their test performances as a series of failures. Questionnaires accompanying the tests assessed causal ascriptions, expectations for future success and affective reactions. As failures accumulated, attributions to inability not only increased but also became more salient in determining variations in shame and expectancy. Low self-concept students were particularly subject to this negative dynamic because they already harbored self-doubts. (Author)