A baboon can do something that most humans find cognitively demanding and many find socially impossible: induce a more powerful individual to attack a third party on its behalf, without the powerful individual realizing it’s being used as a weapon. The maneuver is called a “protected threat.” The baboon appeases the dominant member of its group, positions itself to make a subordinate appear threatening, and maneuvers to prevent the target from doing the same thing in reverse. It’s social tool use—using another organism as an instrument to achieve a goal—and baboons master it at puberty. Chimpanzees, by comparison, don’t learn to use a stone to crack nuts until adulthood. Primates appear to manipulate social objects with more sophistication and at earlier developmental stages than physical tools, which raises an uncomfortable question about what primate brains actually evolved to do.
The answer, according to a hypothesis that has shaped comparative cognition for nearly four decades, is politics.
The Machiavellian intelligence hypothesis
In the 1960s, lemur researcher Alison Jolly noticed something counterintuitive. Lemurs were terrible at manipulating objects—far worse than monkeys at the mechanical problem-solving tasks that laboratories used to measure intelligence. But their social skills were just as sophisticated as monkeys’. Jolly proposed reversing the common assumption: instead of social complexity being a product of intelligence, intelligence might be a product of social complexity. The technical challenges of foraging—finding food, processing it, remembering where it grows—might matter less than the social challenges of living in permanent groups with dozens of individuals who are simultaneously your allies, rivals, mates, competitors, and kin.
Psychologist Nicholas Humphrey extended this in 1976. He’d watched captive monkeys handle laboratory puzzles with impressive skill, but he couldn’t find anything comparably challenging in their natural foraging environment. The hardest problem these animals faced, he argued, wasn’t physical. It was social—navigating a group where every interaction involved weighing cooperation against competition, tracking who owes what to whom, remembering past conflicts and predicting future alliances, and doing all of this with individuals who are simultaneously doing the same calculations about you.
Frans de Waal’s 1982 book Chimpanzee Politics documented the social maneuvering of chimpanzees in terms that read like a dispatch from the Florentine court—coalition formation, strategic alliance shifts, betrayals, reconciliations, and the systematic deployment of social favors as a form of political currency. Andrew Whiten and Richard Byrne formalized the concept in 1988 as the Machiavellian intelligence hypothesis: the pressure to outmaneuver other members of your social group is a primary driver of the evolution of primate intelligence. The brain got bigger not because the environment got harder but because the social group got more complicated.
Robin Dunbar demonstrated a correlation between primate group size and neocortex size—the most recently evolved part of the brain, and the part that expanded most dramatically in the primate lineage compared to other mammals. Larger groups require tracking more relationships, remembering more histories, predicting more behaviors. The cognitive load scales with the number of social connections, not with the complexity of the physical environment. Primates have brains roughly twice as large as expected for mammals of equivalent body size, and the Machiavellian intelligence hypothesis argues that social computation—not tool use, not foraging, not predator avoidance—is the primary reason.
What baboons actually do
Baboon troops are not democracies. They’re hierarchies maintained through a combination of aggression, alliance formation, grooming, and the careful management of social relationships that function as a currency more stable than any physical resource. Male baboons compete for rank through direct confrontation, but rank alone doesn’t determine reproductive success. Males who form alliances—particularly with unrelated males—can collectively outcompete higher-ranking individuals. The alpha male is not always the most reproductively successful male. The most politically connected male sometimes is.
Female baboons form their own hierarchies, typically more stable than male hierarchies and based heavily on kinship. A female’s rank often follows her mother’s, creating lineages of dominant and subordinate families that persist across generations. High-ranking females get better access to food and water, experience lower stress hormone levels, and have offspring with higher survival rates. The fitness consequences of social rank are measurable, heritable, and real.
Grooming is the central social technology. Baboons groom each other for hours daily, and the distribution of grooming is not random. It correlates with alliance patterns, kinship, and—critically—with what the grooming partner can offer in the immediate social marketplace. Research on wild chacma baboons found that female coalitions were not long-term strategic alliances built through reciprocal grooming over months. They were opportunistic, short-term transactions where both parties benefited immediately. Baboons don’t trade favors across time the way the Machiavellian framework originally suggested. They trade in real time, in a social marketplace where the value of a grooming partner fluctuates based on current social conditions.
This finding—published by Silk, Cheney, Seyfarth, and others—complicated the original hypothesis significantly. The Machiavellian framework emphasized long-term strategic planning, deception, and reciprocal exchange. The field data suggested something more like a spot market: baboons assessing the current value of social partners and adjusting their behavior accordingly, not executing multi-step schemes that require remembering who did what three weeks ago.
Tactical deception
Byrne and Whiten documented tactical deception in baboons—behaviors designed to create false impressions in the minds of other individuals. A subordinate baboon feeding on a preferred food item while a dominant individual approaches will sometimes casually move away from the food and adopt a relaxed posture, as if it had finished eating or hadn’t been eating at all. Once the dominant passes, the subordinate returns to the food. The behavior requires, at minimum, an understanding that the dominant’s behavior is influenced by what it believes about the subordinate’s behavior—a rudimentary form of the social cognition that in humans we’d call theory of mind.
Mountain gorillas suppress their copulation vocalizations during secretive matings with subordinate males, conducted out of sight of the dominant silverback. Both the female and the junior male remain silent—a coordinated deception that requires both parties to understand that the dominant male’s response depends on what he perceives. When these matings are discovered, the dominant male invariably attacks the female, adding a punitive dimension to the social calculation: the cost of being caught is asymmetric, falling more heavily on the female, which means the decision to mate secretly involves weighing the reproductive benefit against a gendered risk of punishment.
Dario Maestripieri at the University of Chicago, studying rhesus macaques, found that these monkeys share with humans “strong tendencies for nepotism and political maneuvering.” His conclusion: “Our Machiavellian intelligence is not something we can be proud of, but it may be the secret of our success.” The cognitive machinery that enables a baboon to manipulate a dominant individual into attacking a rival may be the same machinery that, scaled up and elaborated over millions of years, enables a human to navigate corporate politics, negotiate a trade deal, or run for office.
What the critics found
The Machiavellian intelligence hypothesis has generated productive pushback. Barrett and Henzi, studying baboons and other primates in the field, argued that the hypothesis overemphasizes exploitation and deception at the expense of tolerance, coordination, and cooperation. Primate social life, they contended, is not primarily a chess game of strategic manipulation. It’s “an intricate tapestry of competition and cooperation, of aggression and reconciliation, of nonaggressive social alternatives, and of behaviors and relationships that cannot be easily categorized into simple opposites.”
The orangutan problem is frequently cited: orangutans are largely solitary but outperform the highly social baboon on cognitive tests. If social complexity drives intelligence, the most social species should be the smartest. They’re often not. The relationship between sociality and cognition is real but messier than the original hypothesis suggested—group size correlates with neocortex size across the primate order, but individual species frequently violate the pattern.
The current consensus treats the Machiavellian intelligence hypothesis as an important partial explanation rather than a complete theory. Social complexity is a major driver of primate brain evolution, but it’s not the only driver, and the specific form that social cognition takes—long-term strategic planning versus real-time marketplace trading, deceptive manipulation versus cooperative coordination—varies between species in ways the original framework didn’t predict.
Why it matters beyond primatology
The baboon troop is a small-scale version of the problem every human organization faces: how do you maintain a stable group when every member has individual interests that partially conflict with the group’s interests? The baboon’s solution set—hierarchy, coalition, grooming, deception, reconciliation, punishment, nepotism—is recognizable to anyone who has spent time in a corporate office, a political party, or a homeowners association. The specifics differ. The architecture doesn’t.
The deeper implication is about what brains are for. If the Machiavellian intelligence hypothesis is even partially correct, the enormous human neocortex didn’t evolve primarily to solve physics problems or build tools or develop language. It evolved to navigate other humans—to predict what they’ll do, influence what they think, form alliances that advance your interests, and detect when someone is doing the same to you. The math, the engineering, the art, the philosophy—all of it may be a secondary application of cognitive hardware that was built, under evolutionary pressure, for politics.
We cover baboon social intelligence alongside chimpanzee tool traditions, dolphin communication, and the full landscape of animal cognition across our Animal Culture & Knowledge course—including why the most revealing thing about human intelligence might be how much of it we share with a monkey that learned to weaponize its friends.