Cast into doubt: Free will and the justification for punishment.

Criminal punishment is justified on either retributive or consequential grounds. The retributive justification is premised on a common-sense view of free will: offenders can freely choose to commit crimes and so deserve blame for their actions. The consequentialist justification, in contrast, is not necessarily premised on the free will concept, but rather justifies punishment when it is the most cost-effective way of preventing crime. Science elucidating the mechanistic causes of human behavior has thrown the notion of free will into doubt, leading some to predict a shift in public support away from retribution towards consequentialism. Past research shows that free will doubt weakens support for retribution, but less is known about its effects on support for consequentialism, or about whether these effects differ across the crime severity spectrum. In this study, we explore the effects of free will doubt on support for retribution and consequentialism in response to three different categories of crime - drug crime, property crime, and violent crime - which have been shown to evoke varying levels of emotion. We find clear inconsistencies across the crime spectrum. For high affect crime, free will doubt weakens support for retribution via blame, and increases support for consequentialism. For low affect crime, free will doubt weakens support for retribution to an even greater extent, yet also decreases support for consequentialism via blame. These findings suggest that, as science reveals the mechanistic causes of criminal behavior, support for criminal punishment will decrease, especially with respect to less serious crimes.