Mr. Kahan, for example, has said that shaming penalties are good because they are expressive. They use the power of humiliation to express social values and moral outrage. Shame certainly has an extra moral oomph that other types of punishment, including prison, fines and public service, lack. For a man who solicits prostitutes, it is far worse punishment to carry a placard announcing that fact than it is to pay a fine. For a man who urinates on the street, it is far worse to be made to clean the spot with a toothbrush than to do public service.
Shame is primitively effective.
Yet its primitive appeal is also its weakness. Rather than punishing the criminal, the state leaves it up to the mob to decide what to do. Ms. Nussbaum suggests that shame's primitivism is tribal. Shame, like disgust, brands the person rather than the act itself. And that kind of stigmatization, Ms. Nussbaum said, tends to spread to groups who haven't done anything wrong.