The Evolution of (Our Intuitive Belief in) Free Will
The concept of free will and whether we have it or not has been debated by philosophers for at least the past two thousand years (O’Connor & Franklin, 2022). Free will is broadly defined as having a significant degree of control over one’s actions. For example, the degree to which you have control over reading this article, instead of it simply being the result of a long causal chain of events that led to you reading it. While the specific details of the arguments made by individual philosophers on the issue vary considerably, there are three main schools of thought: libertarian free will, determinism, and compatibilism. Within these three schools of thought, there are two main types of arguments: the freedom to do otherwise, and sourcehood arguments. Different schools of thought and the different philosophers within them tend to vary in the amount of emphasis placed on each type of argument. Simply put, libertarians (in the free will, not political sense) believe that we do have the freedom to do otherwise. Whereas determinists believe that we do not, because all events are caused by the deterministic laws of nature, from which we are not exempt. Compatibilists accept that events are caused by the deterministic laws of nature, but use sourcehood arguments to claim that if the actions come from within ourselves, then they are acts of free will.
Most philosophers believe free will to be a near-universal human trait (O’Connor & Franklin, 2022). And this intuitive belief in free will appears to develop in children between four and six years of age (Kushnir et al., 2015). Various studies have found that a belief in free will is shared by ordinary citizens (Baumeister et al., 2011; Nahmias et al., 2005; Monroe & Malle, 2010; Shepard & Reuter, 2012). However, upon further inspection, their views would seem to most align with compatibilism, where it is about the sourcehood of one’s actions, rather than the more metaphysical question of whether we have the freedom to do otherwise or not. Yet, this question of the freedom to do otherwise is what has been traditionally emphasized by philosophers (Banja, 2015), and there is significant psychological and neuroscientific evidence that undermines this notion (King & Appleby, 2021; Wegner, 2018).
Interestingly, many studies have shown that a strong intuitive belief in free will is associated with behavior that is beneficial to functioning well in social groups (Baumeister & Monroe, 2014). For example, increased performance, helpfulness, gratitude, aggression restraint, learning through reflection, and individual thinking. So, whether free will is true or not, having a strong intuitive belief in it would seem to facilitate social harmony, and the cognitive capacities necessary for it seem likely to be evolutionary adaptations to aid group cooperation (Baumeister et al. 2011).
“It is likely that our intuitive belief in free will is underpinned by the combination of several cognitive capacities which can be described as our executive functions.”
Psychological analysis
It is likely that our intuitive belief in free will is underpinned by the combination of several cognitive capacities which can be described as our executive functions. These executive functions are primarily associated with prefrontal regions of the frontal lobes (Stuss & Alexander, 2000), particularly the dorsolateral prefrontal cortex (Alvarez & Emory, 2006), the orbitofrontal cortex, and the anterior cingulate cortex (Lezak et al., 2004). The dorsolateral prefrontal cortex is responsible for things like planning, response inhibition, working memory, organizational skills, reasoning, problem-solving, and abstract thinking (Alvarez & Emory, 2006). The orbitofrontal cortex is responsible for things like impulse control, monitoring of ongoing behavior, and socially appropriate behaviors (Lezak et al., 2004). And the anterior cingulate cortex is responsible for things like the inhibition of inappropriate responses, decision making, and motivated behaviors.
One component that would be particularly crucial for having an intuitive belief in free will is self-awareness. This is because it would be impossible to conceive of yourself as being in control without first having an underlying sense of self that one could control. And it may be that having a strong need for control is an inevitable by-product of an organism having this sense of self. Another component that would be of particular importance is the ability to mentally travel in time, or what is otherwise known as episodic memory and episodic foresight. This is because episodic memory allows us to recall past experiences and contemplate what we could have done differently, and episodic foresight allows us to consider multiple possible futures, providing a sense that we are actively participating in choosing one of several possibilities to pursue.
Roy F. Baumeister and colleagues (2011) argue that self-control, rational choice, planning, and initiative are the cognitive processes that underpin actions that are judged by others as free. That is, because we can inhibit our emotions and natural impulses, rationally contemplate different options, make plans, and then act on them, it gives us the sense of having free will. These capacities are assumed to be evolutionary adaptations to uniquely human social life, to enhance cooperation and enable culture. It is argued that these capacities evolved to enhance rule-following so that individuals could better participate in roles that then enhance the lives of both the individual and the group. For these reasons, it seems likely that we are the only species that experience a strong intuitive belief in free will, although other species may experience it to a lesser degree.
“The best estimate we can go on is measures of competencies of the cognitive capacities that are likely necessary for the conscious experience of free will.”
Comparative analysis
However, without the capacity for animals to tell us if they do have some sense of free will, it is difficult to determine whether they do or not. Although other animals display capacities for communication, the available evidence suggests that other animals have minimal competency in human language (Suddendorf, 2013). The best estimate we can go on is measures of competencies of the cognitive capacities that are likely necessary for the conscious experience of free will. It has been argued that metacognitive executive functions such as rational choice and planning are uniquely human, and likely the result of the evolution and development of “conceptualization instruments” such as language (Ardila et al. 2008). But that emotional executive functions may be shared with other primates since they are likely the result of the biological evolutionary processes that we share with other primates.
Studies of our evolutionary relatives support the idea that metacognitive executive functions are limited in other primates. One study compared various abilities related to self-control between humans, and that of our closest relatives, chimpanzees (Herrmann et al. 2015). They found that three-year-old humans and chimpanzees have comparable levels of self-control, but that our uniquely human capacity for self-control develops at around six years old. Another study tested chimpanzee capacity for working memory, an executive function necessary for rational choice and planning (Völter et al., 2019). They used a working memory paradigm that is similar to the one used with human children so that their results could be compared. They found that chimpanzees have a capacity for working memory that is similar to that of seven-year-old human children.
The passing of mirror self-recognition tests has been argued to be a measure of self-awareness (Gallup, 1998), but their passing may simply be evidence of an animal having a mental visual representation of themselves (Nielsen et al., 2006). In any case, a review found that only 43% of chimpanzees and orangutans pass the test (Swartz et al., 1999). And further studies have found that various monkeys (Anderson & Gallup, 2011) and gibbons consistently fail the test (Suddendorf & Collier-Baker, 2009). A planning of mutually exclusive possibilities test has been proposed as a way to investigate if a being has a rudimentary capacity for episodic foresight (Redshaw & Suddendorf, 2016). In one experiment, a desirable item is dropped down a pipe so that it could potentially be obtained from one of two openings. Results found that chimpanzees and orangutans consistently fail the task by only preparing for one possible outcome, whereas human four-year-old children consistently succeed by preparing for them both. However, this task is quite unusual and unlike anything that a primate would need to perform in the wild, and this lack of ecological validity may be a plausible reason why they fail the task.
Thomas Suddendorf (2018) argues that other animals demonstrate some capacity for communication, memory, physical/social reasoning, empathy, and tradition. But, it is our human urge to connect our mental scenario-building minds with others that have transformed these more basic capacities into more advanced forms such as language, mental time travel, mind reading, abstract explanations/predictions, morality, and culture. In terms of our intuitive belief in free will, this is consistent with what Baumeister and colleagues (2011) argue, since the necessary traits are relevant to getting along with others to form a stronger collective whole, which would then in turn increase our inclusive fitness. However, there may just be an absence of evidence in the way that other animals may possess these capacities and we have simply not tested enough species and/or tested them in ways that are ecologically valid for us to have found the evidence of competencies yet.
“Daniel C. Dennett argues that free will has slowly evolved, becoming more advanced over time, exactly because organisms exist in a deterministic world, which allows them to better adapt to that predictability.”
Evolution
The compatibilist philosopher Daniel C. Dennett (2004) argues that free will has slowly evolved, becoming more advanced over time, exactly because organisms exist in a deterministic world, which allows them to better adapt to that predictability. However, organisms have also needed to evolve mechanisms to avoid being predictable themselves, which would otherwise make them more likely to fall prey to other organisms (Brembs, 2011). Studies have shown that even small insects such as flies and cockroaches have highly variable behavior patterns to avoid being predictable. Behavioral variability would seem to be an evolutionarily adaptive trait, one that can make life appear to be non-deterministic. The default mode network in human brains causes fluctuations in neuronal activity which can explain a great deal of variability in human behavior. It may be that the default mode network evolved for that very purpose. Although, quantum physics has taught us that at what may be the most fundamental level of reality, our world is not deterministic, it is probabilistic. This makes the distinction between determinism and indeterminism a false dichotomy since the probabilistic small scale interacts with the more deterministic larger scale. Roger Penrose and Stuart Hameroff’s (2007) orchestrated objective reduction theory suggests that quantum computations may occur in the microtubules that exist in neurons, potentially affecting the firing of neurons and our experience of consciousness. So, it may be that quantum physics plays a role in our conscious experience of free will. All of this suggests that what is experienced as free will is likely an evolutionary adaptation to the scientific properties of our environments, where its evolution has been gradual.
The archeological evidence of the development of executive functions that together are likely necessary for our strong intuitive belief in free will is varied depending on the specific trait (Coolidge & Wynn, 2001). But the consensus of paleoanthropologists is that evidence for the cognitive capacities necessary for our complex culture (e.g., artforms and ritual) is present by the European Upper Paleolithic period between 50,000 and 12,000 years ago. It is argued that traps that capture prey remotely used during the European Mesolithic between 15,000 and 5,000 years ago are the earliest evidence of the development of sophisticated inhibition and self-control. It is also argued that the colonization of Sahul (i.e., the formerly connected landmass that was comprised of what is now New Guinea and Australia) approximately 60,000 years ago required planning due to needing to use watercraft to get to what would have been an unseeable landmass. And the earliest evidence for the sequential working memory necessary for sophisticated planning is argued to be the barbed bone points discovered in the Katanda Territory of the Democratic Republic of the Congo, estimated to be around 100,000 and 50,000 years old. Michelle C. Langley and Thomas Suddendorf (2020) argue that various mobile containers for tools present in the archaeological record from approximately 100,000 years ago onwards are the best evidence we have for the evolution of episodic foresight.
Based on the current evidence, it would seem as though our intuitive belief in free will would have only evolved within approximately the last 100,000 years, which is very recent on an evolutionary time scale. And it seems rather unlikely that other animals possess an intuitive belief in free will. While some other large primates can demonstrate awareness of themselves in mirrors, it is far from consistent. And the consistent failure of chimpanzees and orangutans to pass the planning of mutually exclusive possibilities tests (Redshaw & Suddendorf, 2016) further supports this conclusion. Given that the mirror self-recognition and the planning of mutually exclusive possibilities tests are likely only testing for minimal competency in self-awareness and mental time travel, these experimental results lend credence to the idea that self-awareness and mental time travel are likely so low in other primates that it would be impossible for them to experience an intuitive belief in free will. But, to gain greater clarity on this, future research could employ other variations of the self-recognition and planning of mutually exclusive possibilities tests on a wider variety of species that consider ecological validity and the specific species’ motivation to engage in the tasks. Along with generally testing for competencies in other executive functions. In conclusion, if we are to find more certainty that we truly are the only species with an intuitive belief in free will, then more extensive testing of a wide range of animals will need to be conducted. But, for now, the current evidence base suggests that we are the only species on the planet that has the extraordinary ability to think that we are in control of ourselves.
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