It’s often assumed that capital punishment is about fighting crime, just retribution or desert, or perhaps about anger and revenge, but in reality it’s much more about signaling. And by signaling I don’t mean the signaling of threats to potential murderers so that they are deterred, or the signaling of the “just” nature of a society that takes an eye for an eye. Proponents of capital punishment, by expressing their support for it, signal their own moral rectitude. Their expression of support refers to high profile crime cases that are widely discussed in the media and that are likely to be familiar to friends, family and others to whom people want to signal. Signaling support for the death penalty in reference to such high profile cases makes the signal particularly strong and deep, partly because it’s so full of familiar and shockingly emotional detail.
Politicians who favor capital punishment and who keep the legal regime in place are equally focused on signaling. They signal that they care about the emotions of the victims of crimes and of the relatives of the victims, and at the same time they signal that they emotionally identify with those who care about the victims of crime. In other words, they signal that they feel connected to the large majority of humanity. And that kind of signal is vitally important for democratic politicians.
Opponents of capital punishment simply don’t have the same signaling power. For example, there’s no large constituency for signals about sympathy for criminals or for signals about anti-instrumentalization. Politicians don’t stand a lot to gain from such signals, and neither do citizens concerned about how others think of them. On the contrary, they risk signaling emotional indifference for the plight of victims and hence they risk lowering their moral standing.
This asymmetry in signaling power between proponents and opponents can explain the persistence of rational arguments in favor of capital punishment, even after they have been shown to be wrong or inconsistent with the facts. (That’s the case for the arguments based on the deterrent effect for instance – see here and here – but also for the arguments based on retribution which are hopelessly circular: a certain punishment is appropriate for a crime because that crime requires a certain punishment). Proponents of capital punishment obviously can’t justify it simply on the basis of emotional identification. They need a more rational story as a cover. And as long as this story can be used successfully in the signaling process, that will do, whether or not the story is factually or logically correct. That will do, because opponents who point to factual or logical failings in the story amplify the signaling of the proponents: by pointing to these failures, the opponents signal rationality and detachment rather than emotional connection, and they thereby make the case for the proponents.
This is counterintuitive, given that it’s most often the opponents of capital punishment who are accused of emotionality and a lack of toughness, but I think it’s the right conclusion.