Many people say that they believe in punishing criminals only to deter further offenses, but a study of people's decisions as mock jurors overwhelmingly suggests that they would punish lawbreakers for the purpose of retribution.
"What's fascinating is that people don't seem to know why they punish," says Kevin Carlsmith of Colgate University in Hamilton, N.Y. Scientists call the main categories of punishment utilitarian, for deterring crime, and retributive, for making a criminal suffer.
Few previous studies have explored what motivates punishments, and those studies simply asked people why they favored a sentence. Carlsmith's three-part study, which appears in the July Journal of Experimental Social Psychology, evaluates the type of information people consider when deciding on a punishment.
In the first test, 132 subjects imagined themselves as jurors and ranked crime-related information in order of its relevance to a sentence. They consistently ranked r