The motivational impact of messages about how to interpret experienced difficulty with schoolwork was tested in two studies. Students read that experienced difficulty with schoolwork is a signal either of the importance or of the impossibility of succeeding in school, rated how much they agreed, and completed a difficult task (Raven's Progressive Matrices). In the absence of reactance (Study 1, N = 93), students' performance reflected an assimilation of the interpretation of experienced difficulty message to which they were randomly assigned. In the presence of conditions conducive to reactance (Study 2, N = 181), the effect on performance was more complex, reflecting contrast with or assimilation to message content depending on message acceptance. Contrast (rejecting the message) bolstered performance if the message was that experienced difficulty implies that the task is impossible, whereas assimilation (accepting the message) bolstered performance if the message was that experienced difficulty implies that the task is important.