Complex sentence: Dissonance is strongest when a discrepancy has been noticed between one's self-concept and one's behavior, e.g., doing something that makes one ashamed; this can result in self-justification as the individual attempts to deal with the threat.
Split into simpler sentences: Dissonance is strongest when a discrepancy has been noticed between one's self-concept and one's behavior, e.g., doing something that makes one ashamed. This can result in self-justification as the individual attempts to deal with the threat.