One of the most hopeful and gratifying conclusions to come out of our 12 years of research on shame and guilt is that that notion of morality is wrong. Dead wrong. You don't have to feel really bad to be a good person. In fact, if anything, the data suggest to the contrary. In the realm of moral emotions, more is not necessarily better. Moderately painful feelings of guilt about specific behaviors motivate people to behave in a moral, caring, socially responsible manner. In contrast, intensely painful feelings of shame do not appear to steer people in a constructive, moral direction. Such intense moral pain about the self cuts to our core, exacting a heavy "penance " perhaps. But rather than motivating reparative action, shame often motivates denial, defensive anger and aggression.
qtd. in June Price Tangney, Ronda L. Dearing, Shame and Guilt (Guilford Press, 2003)