Prior research demonstrates a willingness to incur costs to punish norm violators. But, how strong are the motives underlying such acts? Will people rely on "excuses" to avoid acting on costly punishment intentions, as with other costly pro-social acts? In a laboratory experiment, we find that...

Punishment can lose its legitimacy if the enforcer can profit from delivering punishment. We examine how justification can promote the legitimacy of punishment in a one-shot sender-receiver game where an independent third party can punish the sender upon seeing whether the sender lied. Most...