Most of us consider that we have “free will”, the power to make our own choices and to control our actions. This experience stems in part from the fact that our conscious experience of intention precedes the moment we act. Feeling ‘free’ greatly influences one’s own perception of individual responsibility: We say we are responsible for our actions if we “could have done otherwise”. Does this perception of responsibility influence moral behaviour? Many studies have highlighted the prosocial benefits of believing in free will. For instance, inducing a belief in free will reduces cheating behaviour and increases one’s willingness to make efforts. However, things are not that simple. Believing in free will has also been associated with stronger retributive attitudes towards others: if you judge that a person who committed a crime was truly free to decide how to act, then that person should be punished more severely than if there are mitigating circumstances that partially explain the crime.
In our recent study, we used a paradigm that engages morality in which two participants (the ‘agent’ and the ‘victim’) took turns to administer (or not) electrical shocks to each other in order to receive a small financial benefit. To study to what extent belief in free will influences the number of shocks delivered to the ‘victim’, we used an experimental manipulation known to induce disbelief in free will, — reading an excerpt that challenges the existence of free will (e.g, by claiming that human behaviour is totally determined by genetics). Half of our participants read such an excerpt; the other half read a neutral text without any mention of free will.
Strikingly, we observed that this manipulation increased prosocial behaviour: agents administered fewer painful electric shocks to the ‘victim’ after being induced to believe that free will does not exist. In addition, vindictive behaviour was also reduced after being primed against free will. In previous studies (Caspar, Christensen, Cleeremans & Haggard, 2016), we observed that participants who played the role of victim first tend to administer more shocks than they had received when subsequently playing the role of the agent, thus behaving vindictively. We also observed this result in the present experiment, but not for participants who received the prime inducing disbelief in free will. Importantly, we observed that these effects were mostly driven by gender: the increase of prosocial behaviours was only present for female participants. This observation turns out to be very important, as most studies in this domain report samples in which females vastly outnumber males. Why female participants appear to be more influenced by the procedure remains to be examined but the fact that males and females differ in their core beliefs (i.e., men score higher in scientific determinism and women score higher in free will) may be an explanatory factor.
To resume, we observed that inducing disbelief in free will increases prosocial behaviours by reducing vindictiveness. This effect is probably driven by the fact that reducing beliefs in free will impacts the notion of individual responsibility, since people’s behaviours are guided by predeterminant factors. This thus makes people less retributive toward others.
A plethora of factors can be put forward to explain what guides the decision of individuals to perform actions judged as ‘right’ or ‘wrong’. Amongst them, our own belief to be a free agent or an entity who has no control at all over his own action appears to be significant. Even if the road is still long and arduous to understand how exactly our beliefs influence our moral behaviours, it clearly appears that both believing in free will or in determinism can have positive impact on morality.