Criminologists have long grappled with the varying effect of sanctions. In an effort to clarify these divergent effects, Sherman (1993) delineated a general theory of sanction effects, termed defiance theory. Defiance theory anticipates that there are four necessary conditions for defiance to occur: (a) the sanction must be perceived as unfair; (b) the offender must be poorly bonded; (c) the sanction must be perceived as stigmatizing; and (d) the offender denies the shame produced by the sanction. This study provides one of the first empirical assessments of defiance theory. In addition, defiance theory is examined within the life-course perspective, and analyses address trajectories of offending. Using data from the 1945 Philadelphia Birth Cohort, the results yield promising support for the theory.