The question of whether free will exists or not has been debated in philosophy for centuries, with competing views of various accounts (Dilman,
1999). More recently, cognitive neuroscientists and psychologists have tried to address this question empirically. Several studies found that voluntary actions are preceded by specific patterns of neural activity several hundred milliseconds before awareness (Fried et al.,
2011; Haggard & Eimer,
1999; Libet et al.,
1983,
1993; Soon et al.,
2008). This observation has led some neuroscientists to the assertion that conscious free will is nothing more than an illusion (Crick,
1994; Harris,
2012; Libet et al.,
1983). Although this viewpoint received various criticism (Brass et al.,
2019; Radder & Meynen,
2013; Roskies,
2010; Schurger et al.,
2021), it has become a popular topic in public media (Burkeman,
2021; Cave,
2016; Nichols,
2011). While lay people generally believe that free will exists, these anti-free will messages might challenge their beliefs in free will. In philosophy, there are competing ideas about the impact of disbelief in free will. Some philosophers have argued that disbelief in free will could have a severe negative impact on moral behavior (Smilansky,
2000,
2002), while others argue that it could have a positive impact on behavior, such as a decrease in retributivism (Shaw et al.,
2019). Given these theoretical controversies, it is important to investigate what impact changing lay people’s beliefs in free will really has.
Previous approaches investigating free will beliefs
In recent literature, there have been two streams of research investigating the impact of changing lay people’s beliefs in free will, namely social psychology and experimental philosophy (Nahmias et al.,
2014; Vohs & Schooler,
2008). Within social psychology, researchers have used direct experimental manipulations to investigate the causal effects of FWB on downstream processes (Baumeister et al.,
2009; Sharrif et al.,
2014). Past research mainly used the so-called Crick method as an experimental manipulation technique, first introduced by Vohs and Schooler (
2008). Participants were randomly assigned to an anti-free will group or a control group, where they either read a passage arguing against the existence of free will (i.e. a passage from “The Astonishing Hypothesis” by Francis Crick (Crick,
1994)), or a passage about consciousness without mentioning free will (Vohs & Schooler,
2008). After reading the text, a dependent variable is measured (e.g. prosocial behavior), and a self-report questionnaire on free will beliefs is administered as a manipulation check (Ewusi-Boisvert & Racine,
2018). These studies found that inducing disbelief in free will increases antisocial behaviors (Baumeister et al.,
2009; Protzko et al.,
2016; Vohs & Schooler,
2008), have an impact on cognitive factors (Rigoni et al.,
2015), and impacts ideas of morality and justice (Sharrif et al.,
2014).
Alternatively, in experimental philosophy, hypothetical vignette studies are employed to investigate laypersons' beliefs in free will. In these studies, researchers create scenarios in which they sketch a world where a certain person has to make a decision, which can either be in their own control (i.e. free condition) or out of their own control (deterministic condition). Afterward they are asked questions regarding attributions of free will within the context of this scenario (e.g. responsibility, moral behavior) (Nahmias et al.,
2014; Shepard & Reuter,
2012; Shepherd,
2012). Here, instead of using a direct experimental manipulation, this approach creates a hypothetical scenario. Additionally, instead of measuring general FWB, FWB are measured within the specific context of the vignette and investigate how these relate to other concepts.
Both approaches have their pros and cons. An advantage of both approaches compared to correlative approaches is that they use experimental manipulations and therefore allow to draw causal inferences. The social psychological approach, however, has been heavily criticized because key findings could not be replicated (Eben et al.,
2020; Genschow et al.,
2020,
2021; Nadelhoffer et al.,
2020). A recent meta-analysis showed that while free will belief manipulations have a reliable effect on free will beliefs as measured by questionnaires, downstream effects on other variables such as social behavior were primarily driven by underpowered studies (Genschow et al.,
2021). Furthermore, the question arises whether effects on free will related beliefs questionnaires are due to demand effects (Mummolo & Peterson,
2019). After all, it is difficult to imagine that reading a short text changes a complex belief system that has been acquired over a lifetime (Tavernier, Wisniewski, Brass, in prep.). The main advantage of the experimental philosophy approach is that it does not rely on changing free will beliefs. By creating a hypothetical scenario, it only requires that participants are willing to imagine themselves in this scenario. This is of course also its weakness. Vignette studies often employ highly hypothetical, counterfactual, and far-fetched scenarios, thus relying heavily on the imagination of the participant. Furthermore, the approach does not investigate how people behave but only how people imagine to behave.
To conclude, the FWB literature is still in need of an effective method of manipulation, which allows us to investigate the relation between FWB and downstream processes. The social psychology approach does not provide such an effective method of manipulation as these studies fail to replicate an impact on downstream processes, and consist of demand effects and complex philosophical arguments. Moreover, the experimental philosophy approach does not provide such an effective method either as these focus on hypothetical scenarios that are far-removed from real-life behavior, and a transfer to general beliefs outside the context of the vignette is typically not assessed.
The goal of the current study is to overcome some of the limitations of the two outlined approaches by merging both approaches in an online gaming setting. Such a setting enables us to let participants experience a reduction of free will directly, and creates a FWB manipulation that is not based on understanding complex philosophical arguments or counterfactual scenarios. We know from past research that agency and FWB are closely related (Aarts & van de Bos,
2011; Feldman,
2017; Lynn et al.,
2014), suggesting that experiencing limited agency over actions and outcomes decreases beliefs in free will. Therefore, we implemented the manipulation of reduced agency in the low free will scenarios. Similar to the social psychology approach, we used a direct experimental manipulation instead of a hypothetical manipulation as in the experimental philosophy approach. By doing so, we could investigate participants’ beliefs and behavior. Importantly, we replaced the text-based manipulation by an experience-based manipulation of reduced agency. However, similar to the experimental philosophy approach, we create a hypothetical scenario in which participants experience this reduction of agency. We hypothesized that experiencing reduced agency over one’s own action and their outcome would decrease beliefs in free will (Hypothesis 1) and increase beliefs in determinism (Hypothesis 2). Furthermore, we investigated whether the manipulation of reduced agency impacted FWB within the context of the scenario, and whether this transferred to participants’ general beliefs (
Study 1 vs. Study 2). Combining the social psychology approach and the experimental philosophy approach opens up new opportunities to study free will beliefs and their impact on downstream processes, with ample room for refinement of the FWB research methodology.
The current study
Across two pre-registered studies with a total sample size of 599 participants, we created a novel FWB manipulation technique by merging experimental manipulation and vignette techniques. We described a scenario similar to a vignette study, but then, letting participants experience the described scenario directly instead of just letting them imagine it. Across 3 conditions, participants played online videogames where they experienced more or less agency over actions and outcomes. In a first study, similar to the experimental philosophy approach, we investigated whether this experience affected free will and determinism beliefs within the context of the online video game (“Within the context of the scenario, would the agent believe in free will?”). Similar to the social psychology approach, we manipulated FWB directly. Thus in a second study, we investigated whether this experience of reduced agency over actions and outcomes affected general free will and determinism beliefs (“Do you believe in free will?”).