Proc. Natl Acad. Sci. USA 114, 10071–10076 (2017)

Credit: Enterline Design/Alamy Stock Photo

The existence of free will has been debated since the earliest philosophers and continues to be debated within modern science. Whether it truly exists or not, a personal belief in free will has been shown to affect individuals’ social behaviours, such as rule following and prosocial actions. But does belief in free will also affect how we perceive the actions of others?

In a recent study, Genschow and colleagues from the University of Cologne and Ghent University investigated the impact of belief in free will on our assessments of other peoples’ responsibility for their actions. Belief in free will may cause people to overemphasize the role played by personal choice and underestimate the influence of external factors on others’ actions — this is known as the ‘correspondence bias’. Initial experiments replicated existing work showing participants’ belief in free will does correlate with their degree of correspondence bias. In two further experiments — one a high-powered, pre-registered replication — the authors manipulated belief in free will by having participants read arguments against its existence. The results confirmed that reducing belief in free will caused people to lend greater credence to external factors over personal choice. Finally, the authors showed that this effect extended to participants’ willingness to punish hypothetical others for their rule breaking and to reward positive behaviour.

The work suggests that belief in free will has an effect not just on our own behaviours but also on our perception of the behaviours of others. Challenging beliefs in free will could alter attribution of blame across many domains where humans judge the actions of others.