My friend June Thunderstorm and I once found ourselves captivated by a seemingly simple scene: an inchworm in a meadow by a mountain lake. For a good half hour, we watched it dangle from a grass stalk, twisting and turning in every direction before leaping to another stalk, repeating the process. This inchworm continued its circuitous journey, expending considerable energy, for what appeared to be absolutely no discernible reason.
“All animals play,” June had remarked to me once, drawing on her years as a professional gardener and observer of nature. “Even ants.” She had witnessed countless such moments, prompting reflection and wonder. With a subtle air of triumph, she gestured towards the inchworm and asked, “See what I mean?”
Upon hearing this anecdote, many would immediately demand evidence. What’s the proof that the inchworm was actually playing? Could its seemingly aimless movements have been a hunt for unseen prey? Or perhaps a complex mating ritual? Can we definitively rule out these possibilities? Even if it was playing, what’s the guarantee that this play lacked a practical purpose? Could it not be exercise, or training for some future, unforeseen inchworm emergency?
This skeptical reaction mirrors the perspective of many professional ethologists. In the field of animal behavior, scientific analysis often hinges on the tacit assumption that animals operate under the same cost-benefit analyses we apply to economic transactions. This implies that any expenditure of energy must be directed towards a tangible goal: acquiring food, defending territory, establishing dominance, or maximizing reproductive success. To suggest otherwise requires irrefutable proof, a near-impossible standard in such nuanced matters.
It’s crucial to understand that this approach isn’t necessarily about a scientist’s personal beliefs regarding animal cognition. It’s not about whether they believe animals are “thinking” machines. The point is that ethology, to maintain its scientific rigor, often defaults to explaining behavior in rational, quantifiable terms. This often translates to describing animal actions as if they were driven by economic calculations, aimed at maximizing some form of self-interest – regardless of the scientist’s underlying theory of animal psychology or motivation.
This is precisely what’s behind the somewhat scandalous status of animal play in intellectual circles. It remains understudied, and those who do explore it are sometimes viewed as unconventional. Like any notion that challenges established paradigms, proving animal play exists often involves overly stringent criteria. Even when acknowledged, research frequently attempts to diminish its significance by seeking survival or reproductive functions, effectively undermining the very concept of play as intrinsically motivated behavior.
Despite this resistance, those who delve into the study of animal play consistently conclude that it’s a widespread phenomenon across the animal kingdom. It’s not limited to the usual suspects like monkeys, dolphins, or puppies, but extends to creatures as diverse as frogs, minnows, salamanders, fiddler crabs, and yes, even ants. Ants, famously industrious, have been observed engaging in playful individual activities and even organizing mock battles, seemingly just for the sheer enjoyment.
So, what’s the underlying reason animals play? Perhaps a more pertinent question is: what’s so strange about actions performed purely for the pleasure of acting, the exercise of capabilities for the joy of exertion? What does it reveal about our own human perspective that we instinctively find this idea so puzzling? Why do we assume purpose must always be externally driven?
Survival of the Misfits
The inclination to interpret the biological world through an economic lens has roots stretching back to the very inception of Darwinian science in the 19th century. Charles Darwin himself adopted the phrase “survival of the fittest” from Herbert Spencer, a sociologist admired by the industrialists of the era. Spencer was struck by the parallels between natural selection, as described in On the Origin of Species, and his own theories of laissez-faire economics. Competition for resources, rational calculation of advantage, and the elimination of the weak became perceived as the fundamental laws of the universe.
This new perspective, portraying nature as a brutal arena of relentless struggle, carried significant implications and faced early opposition. An alternative interpretation of Darwinism emerged in Russia, emphasizing cooperation, not competition, as a primary driver of evolutionary change. This viewpoint gained prominence in 1902 with the publication of Mutual Aid: A Factor of Evolution by Peter Kropotkin, a naturalist and revolutionary anarchist. In direct response to social Darwinists, Kropotkin argued that their theoretical foundation was flawed: species that excel at cooperation tend to be more successful in the long run. Kropotkin, born into Russian aristocracy but renouncing his title, spent years in Siberia as a naturalist before being imprisoned for revolutionary activities and eventually fleeing to London. Mutual Aid originated from essays written as a rebuttal to Thomas Henry Huxley, a prominent Social Darwinist, and articulated the prevailing Russian understanding: while competition undoubtedly played a role in evolution, cooperation was ultimately the decisive factor.
The existence of animal play is considered something of an intellectual scandal.
The Russian challenge resonated within 20th-century biology, particularly in the burgeoning field of evolutionary psychology, even if it wasn’t always explicitly acknowledged. It became incorporated into the broader “problem of altruism”—another term borrowed from economics and central to debates among “rational choice” theorists in social sciences. This was the question that perplexed Darwin himself: what’s the evolutionary advantage of animals sacrificing their individual interests for others? It’s undeniable that they sometimes do. Why would a herd animal risk attracting a predator’s attention by warning others of danger? Why would worker bees sacrifice their lives to protect their hive? If scientific explanations necessitate attributing rational, maximizing motives, then what exactly was a kamikaze bee trying to maximize?
The answer, facilitated by the discovery of genes, eventually became clear. Animals were, in essence, striving to propagate their own genetic code. Interestingly, this neo-Darwinian perspective was largely developed by individuals who considered themselves radicals. J.B.S. Haldane, a Marxist biologist, famously quipped in the 1930s that he would gladly sacrifice his life for “two brothers or eight cousins,” reflecting this gene-centric view. Richard Dawkins’s The Selfish Gene, epitomized this line of thought, portraying biological entities as “lumbering robots” programmed by genes acting as ruthless “Chicago gangsters,” relentlessly expanding their territory to propagate themselves. Such descriptions were often qualified with disclaimers like, “Of course, this is just a metaphor, genes don’t really want or do anything.” However, neo-Darwinists were essentially driven to these conclusions by their foundational premise: that science demands rational explanations, which translate to attributing rational motives to behavior, and that true rationality is synonymous with selfishness or greed in human terms. Consequently, neo-Darwinism surpassed even Victorian Social Darwinism in its starkness. If Herbert Spencer’s Social Darwinism depicted nature as a cutthroat marketplace, neo-Darwinism presented an outright capitalist universe. It assumed not just a struggle for survival, but a realm of rational calculation fueled by an seemingly irrational drive for unlimited growth.
This was the context in which the Russian challenge was understood. However, Kropotkin’s actual argument is far richer. He emphasized how animal cooperation often transcends survival or reproduction, becoming a source of pleasure in itself. “To take flight in flocks merely for pleasure is quite common among all sorts of birds,” he observed. Kropotkin provided numerous examples of social play: vultures soaring together for entertainment, hares playfully boxing with other species (even foxes), flocks of birds performing coordinated maneuvers, and groups of squirrels engaging in wrestling and games:
We know at the present time that all animals, beginning with the ants, going on to the birds, and ending with the highest mammals, are fond of plays, wrestling, running after each other, trying to capture each other, teasing each other, and so on. And while many plays are, so to speak, a school for the proper behavior of the young in mature life, there are others which, apart from their utilitarian purposes, are, together with dancing and singing, mere manifestations of an excess of forces—“the joy of life,” and a desire to communicate in some way or another with other individuals of the same or of other species—in short, a manifestation of sociability proper, which is a distinctive feature of all the animal world.
Exercising one’s abilities to their fullest extent brings inherent pleasure in existence itself. For social creatures, these pleasures are amplified when shared. From Kropotkin’s perspective, this is self-evident. It’s simply the essence of life. We don’t need to explain why creatures desire to live. Life itself is its own purpose. And if being alive entails possessing capabilities—to run, jump, fight, fly—then the exercise of these capabilities for their own sake requires no further justification. It’s a natural extension of the fundamental principle of life.
Friedrich Schiller, as early as 1795, argued that play is the very origin of self-consciousness, and consequently, freedom and morality. “Man plays only when he is in the full sense of the word a man,” Schiller wrote in On the Aesthetic Education of Man, “and he is only wholly a Man when he is playing.” If Schiller and Kropotkin are correct, then hints of freedom, even morality, are present throughout the natural world.
Unsurprisingly, this aspect of Kropotkin’s argument was largely ignored by neo-Darwinists. Unlike “the problem of altruism,” cooperation for pleasure, as an intrinsic value, couldn’t be easily incorporated into their ideological framework. In fact, the 20th-century version of the struggle for existence left even less room for play than its Victorian predecessor. Herbert Spencer himself had no issue with purposeless animal play, seeing it as a mere outlet for surplus energy. Just as a successful businessman might relax with a game of cards or polo, why shouldn’t animals who thrived in the struggle for survival also enjoy some leisure? However, in the new, fully capitalist version of evolution, where the drive for accumulation was limitless, life became a mere instrument for DNA propagation, and the very existence of play became something of an anomaly, a scandal.
Why Me?
It’s not just a scientific reluctance to acknowledge play—and thus, potentially, the seeds of self-consciousness, freedom, and morality—in animals. Many scientists are increasingly struggling to justify these attributes even in humans. Once all living beings are reduced to market actors, rational calculating machines driven by genetic code propagation, it implies that not only our cells but also our evolutionary ancestors lacked anything resembling self-consciousness, freedom, or moral life. This raises a fundamental question: what’s the evolutionary pathway through which consciousness – a mind, a soul – could have emerged in the first place?
The American philosopher Daniel Dennett articulates this problem clearly using lobsters as an example. Lobsters, he argues, are essentially robots. They function perfectly well without any sense of self. What’s it like to be a lobster? Probably nothing. They lack anything resembling consciousness; they are machines. Dennett extends this logic up the evolutionary ladder, from our own cells to complex creatures like monkeys and elephants. Despite their seemingly human-like traits, we can’t prove they consciously think about their actions. Then, suddenly, Dennett arrives at humans. While we may operate on autopilot most of the time (at least 95%), we possess this “me,” a conscious self that occasionally surfaces to take charge, directing us to seek new opportunities, quit harmful habits, or write academic papers on consciousness. In Dennett’s words:
Yes, we have a soul. But it’s made of lots of tiny robots. Somehow, the trillions of robotic (and unconscious) cells that compose our bodies organize themselves into interacting systems that sustain the activities traditionally allocated to the soul, the ego or self. But since we have already granted that simple robots are unconscious (if toasters and thermostats and telephones are unconscious), why couldn’t teams of such robots do their fancier projects without having to compose me? If the immune system has a mind of its own, and the hand–eye coordination circuit that picks berries has a mind of its own, why bother making a super-mind to supervise all this?
Dennett’s own proposed answer – that consciousness evolved to enable deception, providing an evolutionary advantage – is not entirely convincing. (If so, wouldn’t foxes also be conscious?). The question intensifies when we consider how consciousness arises – the “hard problem of consciousness,” as David Chalmers terms it. What’s the mechanism by which seemingly robotic cells and systems combine to generate qualitative experiences: the sensation of dampness, the enjoyment of wine, a preference for cumbia over salsa? Some scientists honestly admit they have no idea how to explain such experiences and suspect they never will.
Do the Electron(s) Dance?
However, there’s a potential way out of this dilemma, starting with a re-evaluation of our initial assumptions. Let’s reconsider the lobster. Lobsters are often used by philosophers as examples of purely unthinking, unfeeling creatures. This might stem from the unpleasant experience of boiling a live lobster, requiring a justification that the creature isn’t truly suffering. (France, with its lobster-walking philosopher Gérard de Nerval and Sartre’s mescaline-induced lobster obsession, seems to be an exception). But scientific observation reveals that even lobsters engage in play, manipulating objects, possibly simply for the enjoyment of it. If this is true, then calling lobsters “robots” strips the term of its meaning. Machines don’t engage in playful behavior. But if living creatures aren’t robots, many of these seemingly intractable questions begin to dissolve.
What if we reverse our perspective and consider play not as an anomaly, but as a foundational principle, present not only in lobsters and all living organisms but also at every level where we find “self-organizing systems,” as described by physicists, chemists, and biologists?
This idea isn’t as far-fetched as it might initially seem.
Philosophers of science, grappling with the emergence of life from inanimate matter and consciousness from simple organisms, have developed two main types of explanations.
If living creatures are not robots after all, many of these apparently thorny questions instantly dissolve away.
The first is emergentism. This theory posits that at certain levels of complexity, qualitative leaps occur, leading to the “emergence” of entirely new physical laws. These laws are built upon but not reducible to preceding levels. For example, the laws of chemistry emerge from physics; they rely on physical laws but cannot be fully explained by them. Similarly, biological laws emerge from chemistry. Understanding a fish’s chemical components is necessary but insufficient to explain swimming. In the same way, the human mind can be seen as emergent from its constituent cells.
The second position, panpsychism or panexperientialism, acknowledges emergence but argues it’s insufficient. As philosopher Galen Strawson argues, expecting insentient matter to transform into beings capable of discussing insentient matter in just two leaps strains the concept of emergence too far. Something, however minimal, must already be present at every level of material existence, even in subatomic particles – something akin to the qualities we associate with life and mind. This “something” might be a rudimentary responsiveness to the environment, anticipation, or memory. However basic, it would be necessary for self-organizing systems like atoms and molecules to self-organize in the first place.
This debate touches upon fundamental questions, including free will. As countless adolescents have pondered, often under the influence and contemplating the universe’s mysteries, if particle movements in our brains are governed by natural laws, how can free will exist? The standard response is Heisenberg’s uncertainty principle: atomic particle movements aren’t predetermined. Quantum physics predicts probabilities of electron jumps in aggregate, but not the specific jump of an individual electron. Problem solved?
Not quite. Something is still missing. If it only means particles in our brains move randomly, we’d still need an immaterial “mind” to guide neurons non-randomly. But that’s circular – a mind would be needed to make the brain act like a mind.
If these motions are not random, however, a material explanation becomes possible. The prevalence of self-organization in nature – structures maintaining equilibrium within their environments, from electromagnetic fields to crystallization – provides panpsychists with substantial material. One could argue that these entities simply “obey” natural laws (whose existence is unexplained) or move randomly. But this perspective is a chosen viewpoint, leaving the mind’s capacity for such decisions utterly mysterious.
Historically, this approach has been a minority view, largely sidelined in the 20th century and easily ridiculed (“Tables can think?”). However, the argument isn’t about tables thinking, but about the elementary self-organizing components of tables, like atoms, exhibiting rudimentary forms of qualities that, at exponentially higher complexity, we recognize as thought. Recently, ideas from philosophers like Charles Sanders Peirce and Alfred North Whitehead have gained renewed traction in some scientific circles, leading to a revival of panpsychism.
Interestingly, physicists have been more receptive to these ideas than biologists. Physicists, perhaps because they are less constrained by challenges from religious fundamentalists, are more open to playful speculation. They are the poets of science. If one accepts concepts like thirteen-dimensional objects or infinite universes, or that 95% of the universe is dark matter and energy about which we know nothing, then the idea of subatomic particles possessing “free will” or experiences might not be such a leap. Indeed, freedom at the subatomic level is a current topic of debate.
What evolutionary psychologists can’t explain is why fun is fun.
Is it meaningful to say an electron “chooses” its jump? There’s no way to definitively prove it. The evidence we could have – unpredictability – we do have, but it’s not conclusive. Still, for a consistent materialist explanation of the world – one that avoids treating mind as a supernatural imposition but as a complex organization of pre-existing processes – some rudimentary form of intentionality, experience, and freedom would need to exist at every level of physical reality.
So, what’s the reason most of us instinctively reject these conclusions as absurd and unscientific? Or rather, why are we comfortable ascribing agency to DNA (“metaphorically”) but not to electrons, snowflakes, or electromagnetic fields? The answer seems to be the difficulty in ascribing self-interest to a snowflake. If rational explanation is confined to actions driven by self-serving calculation, then rational explanations are impossible at these levels. Unlike DNA, which we can pretend pursues ruthless self-aggrandizement, an electron lacks material self-interest, not even survival. It doesn’t compete with other electrons. If an electron acts freely – if it “does anything it likes,” as Feynman supposedly said – it acts freely for its own sake. This implies that at the very foundation of physical reality, we encounter freedom for its own sake – the most basic form of play.
Swim with the Fishes
Let’s propose a principle, a principle of freedom – or, more formally, a principle of ludic freedom. Let’s hypothesize that the free exercise of an entity’s most complex capacities, under certain conditions, tends to become an end in itself. This wouldn’t be the sole principle in nature, but it could help explain observations, like the universe’s increasing complexity despite the second law of thermodynamics. Evolutionary psychologists can explain “why sex is fun,” but what they can’t explain is why fun is fun. This principle of ludic freedom might offer an answer.
I acknowledge this is a simplification of complex issues, and I don’t claim this “play principle” is definitively true. However, it’s arguably as plausible as current orthodox views that posit a mindless, robotic universe suddenly generating poets and philosophers from nothingness. Seeing play as a natural principle doesn’t necessitate a utopian worldview. It can explain the pleasure of sex but also the pleasure of cruelty. (As anyone observing a cat with a mouse knows, animal play isn’t always benign.) But it provides a framework to re-evaluate the world around us.
Years ago, teaching at Yale, I’d assign a Taoist story, offering an “A” to any student who could explain the final line. (No one ever did.)
Zhuangzi and Huizi were strolling on a bridge over the River Hao, when the former observed, “See how the minnows dart between the rocks! Such is the happiness of fishes.”
“You not being a fish,” said Huizi, “how can you possibly know what makes fish happy?”
“And you not being I,” said Zhuangzi, “how can you know that I don’t know what makes fish happy?”
“If I, not being you, cannot know what you know,” replied Huizi, “does it not follow from that very fact that you, not being a fish, cannot know what makes fish happy?”
“Let us go back,” said Zhuangzi, “to your original question. You asked me how I knew what makes fish happy. The very fact you asked shows that you knew I knew—as I did know, from my own feelings on this bridge.”
The story is often interpreted as a clash between logic and mysticism. But if so, why did Zhuangzi, the writer, portray himself as defeated by his logician friend?
After years of reflection, I realized this was the point. Zhuangzi and Huizi were close friends, enjoying such debates. Zhuangzi was highlighting this very enjoyment. We understand each other’s feelings because, in arguing about the fish, we’re doing what the fish are doing: having fun, excelling at something for the pure pleasure of it – engaging in play. Huizi’s drive to win the argument, and his satisfaction in doing so, demonstrated the falsity of his premise. If even philosophers are primarily motivated by such intrinsic pleasures, the exercise of their highest abilities for their own sake, then this principle likely pervades all levels of nature. This is why Zhuangzi could intuitively recognize it in fish.
Zhuangzi was right. And so was June Thunderstorm. Our minds are part of nature. We can understand the happiness of fishes – or ants, or inchworms – because the drive that compels us to ponder these questions is ultimately the same.
Now, what’s not to love about that?
