Tribal E-Book

Michael Morris

• Herausgeber: Swift Press
• Kategorie: Geisteswissenschaft
• Sprache: Englisch
• Veröffentlichungsjahr: 2024

Seitenzahl: 487

Beschreibung

SHORTLISTED FOR THE FINANCIAL TIMES BUSINESS BOOK OF THE YEAR 'A riveting read that will challenge you to rethink your core beliefs' Adam Grant 'Absolutely spot-on, timely message' Chip Heath 'A vision for collective change' Arianna Huffington Tribalism is our most misunderstood buzzword. We've all heard pundits bemoan its rise, and it's been blamed for everything from political polarization to workplace discrimination. But as acclaimed cultural psychologist and Columbia professor Michael Morris argues, our tribal instincts are humanity's secret weapon. Ours is the only species that lives in tribes: groups glued together by their distinctive cultures that can grow to a scale far beyond clans and bands. Morris argues that our psychology is wired by evolution in three distinctive ways. First, the peer instinct to conform to what most people do. Second, the hero instinct to give to the group and emulate the most respected. And third, the ancestor instinct to follow the ways of prior generations. These tribal instincts enable us to share knowledge and goals and work as a team to transmit the accumulated pool of cultural knowledge onward to the next generation. Countries, churches, political parties, and companies are tribes, and tribal instincts explain our loyalties to them and the hidden ways that they affect our thoughts, actions, and identities. Rather than deriding tribal impulses for their irrationality, we can recognize them as powerful levers that elevate performance, heal rifts, and set off shockwaves of cultural change. Weaving together deep research, current and historical events, and stories from business and politics, Morris cuts across conventional wisdom to completely reframe how we think about our tribes. Bracing and hopeful, Tribal unlocks the deepest secrets of our psychology and gives us the tools to manage our misunderstood superpower.

Leseprobe

To Tatjana

Contents

Introduction: The Riddle of Hiddink

Part I: Tribal Triggers

1. Syncing Up

2. Slaying Giants

3. Visiting the Temple

Part II: Tribal Signals

4. The Rise and Fall of Prohibition

5. Soap Operas and Social Change

6. Inside the History Factory

Part III: Tribal Ripples

7. When Change Spreads, and When It Fizzles Out

8. Toxic Tribalism and Its Antidotes

AcknowledgmentsNotes

Introduction

The Riddle of Hiddink

A year and a half before South Korea would host the 2002 World Cup, the Land of the Morning Calm was anything but. Its national soccer team, usually a regional power, had faltered in the 2000 Asian Cup, failing to beat lightweights like Kuwait. Meanwhile, its archrival and cohost, Japan, had gone undefeated to claim the trophy.

More than sports was at stake. After a difficult century of colonization, war, and political unrest, South Korea had ascended to the elite tier of economies. Its ethos of success through striving and sacrifice helped it land the World Cup. Then the 1997 financial crisis crushed its economy, exposed corruption, and brought a humiliating bailout from abroad. In the wake of this, leaders held out hope that an impressive showing could restore the country’s reputation for competence. But now the world’s oddsmakers were betting that it would be the first-ever host nation to fail to advance beyond group play to the tournament rounds. Yet another humiliation loomed.

The worried chief of the Korean Football Association (KFA), Chung Mong-joon, placed a long-distance call to the Netherlands. On the other end of the line was Guus Hiddink, a graying Dutch coach with a dog-eared passport, a rumpled tracksuit, and a track record for bringing out the talent in teams. In the 1998 World Cup, he led a formerly divided Dutch squad to the semifinals. Along the way, they thrashed South Korea’s Reds 5–0, which both depressed and impressed its soccer overlords. Now, those overlords were asking him to come coach their stumbling team at its moment of truth. From game tapes, Hiddink saw that the team’s style of play remained slow and outdated. He had heard that the KFA meddled in roster decisions, sometimes inserting players based on their social backgrounds rather than just their talents. He called Chung back, apologizing for his Dutch bluntness, and made some unprecedented provisos: absolute roster control, extra-long training camps, and a budget to invite the world’s best for exhibition games.

A month later, the ruddy-faced Hiddink landed in Seoul for his unveiling to the sports press. “I don’t know much about Korea,” he began. This was not false modesty, they later realized, when he didn’t recognize some names of prominent players. However, that lack of recognition might as well have been intentional. Hiddink’s first official act was to announce “open tryouts,” welcoming not only the country’s Alisters but also unknowns just out of high school. All had to prove themselves in demanding drills—and some famous names didn’t make the cut. This riled players and rankled fans in a society with a deep respect for age and experience.

Hiddink taught a tactical system called totaalvoetbal (“total football”), a fast, pressing style in which players move fluidly around the field to create unexpected plays. Perfected by the Dutch, it was increasingly adopted by elite clubs in other countries. From the scrimmages at the first training camp, however, Hiddink could see that this freewheeling style wouldn’t come easily. His players moved the ball in more regimented ways, often predictably passing to more senior teammates. Worse yet, the youngsters he had selected for their speed would balk in front of the net when they had clear shots. Then they’d apologize to the veterans for their mistakes, sometimes reprising this self-criticism in press interviews afterward.

The squad was playing poorly, but Hiddink didn’t cut the underperformers or chide them from the sidelines. Instead, he called a formal meeting. His Korean translator winced when relaying the coach’s gloomy assessment that their current form would result in an early exit from the tournament. To underscore this threat, he reminded them that the Reds had never won a game in five previous World Cup appearances. But if they would commit to a grueling regimen of advanced fitness workouts throughout their long training camp, there was hope. They might gain a stamina advantage like the one that had carried the miracle North Korean team into the 1966 tournament. The men in red met eyes for a moment and answered: “Ye!” They would do whatever it takes.

The coach then stunned the team with a new set of ground rules. The next round of training would be held halfway across the world—at an international soccer facility in the United Arab Emirates—where cutting-edge kinesiologists would lead them through next-level workouts. The Korean press would be ceremoniously uninvited. The changes extended even to matters of grammar: the Korean language’s honorific formulations (which he had learned rookies were using to address their veteran teammates, even in fast-moving situations on the field) were henceforth banned. Hiddink rationalized all these policies in terms of efficiency, but they also transformed the cultural cues surrounding players. Onlookers started to question the coach’s sanity—or at least his sensitivity. Was he “ignoring the cultural differences and asking Koreans to work, play and train like Europeans overnight,” as a New York Times reporter questioned? “Maybe you are right,” Hiddink replied, “or maybe these players can adapt quicker than you think.”

Soon, Hiddink’s bet seemed to be paying off. The changed setting brought out different sides of his players’ identities and fostered their learning. Players carried themselves like the other international pros who were training there. The Korean social habits that had been slowing their play—deference and self-criticism—surfaced less frequently on the field. Veterans became less attached to regimented set pieces. Rookies felt freer to react spontaneously and take scoring opportunities.

Still, as the Reds started their summer 2001 schedule against the world’s best teams, their totaalvoetbal often lapsed into total chaos. A central tactic is swapping positions with a teammate to throw off defenders. But the Reds didn’t have enough experience playing this way to read each other’s minds and mesh with their moves. In May, they fell to France 5–0. After another 5–0 loss in August to the Czech Republic, the Korean press branded Hiddink “Oh Dae Young” (Mr. 5–0). The Reds were losing worse than ever. A retired Reds manager blamed it on the “ignorant” foreigner. The team’s major sponsor, Samsung, canned a pricey TV commercial it had shot featuring the beleaguered coach.

During the extended camp that followed, Reds players continued to hone their skills and build their stamina. However, daily social interactions began to settle into old grooves of the team’s traditions. Veterans like Hong Myungbo (who had played in three previous Cups) guided the rest through the old-fashioned warm-ups the Reds had always done. Longtime staffers regaled players with tales of heroes from past squads. Rituals of camp life reconfigured themselves, such as rookies waiting at meals for veterans to first take a table. Some days they even polished the veterans’ shoes. All of this hit home for Hiddink one day when a rookie confided that it felt somehow wrong—against the Reds’ way—to swap places with a veteran famous for playing his position.

Traditions are invaluable for unifying a team, but these rituals were teaching the wrong lessons. Deference to seniority (whether from Korean habits or now from Reds traditions) impeded totaalvoetbal fluidity. But Hiddink kept faith in adaptation. If these Reds traditions had coalesced in the hothouse environment of training camp, then surely new traditions could be forged the same way. Once again, Hiddink imposed strange policies, this time transforming their daily social interactions. He nixed the veteran-led warmup routines as too “robotic.” He appointed younger players to captain-like roles. He assigned seats for all meals, interweaving rookies and veterans. He sat them together on flights and roomed them together at hotels. He started calling fouls on innocent players repeatedly until they finally protested, then he lauded them for standing up to authority. For players from a culture where even meeting the eyes of an elder can come across as insolent, these were unfamiliar and uncomfortable experiences. But after months of this every day, interacting as equals became the new normal: the new Reds tradition.

As their culture evolved—and their fitness training reached completion—the Reds’ game finally began to gel. In an exhibition game, they crushed Scotland 4–1. In the friendly matches leading up to the Cup, they fought England to an impressive draw. Then the Reds stayed within a goal of reigning champ France. In the sportsbooks, they were still 150to1 nohopers, but the players began to believe.

In the initial group play, their first draw was a towering Polish squad, which to the soccer savants in the broadcast booth portended doom. However, the Reds’ explosive attacks kept the Poles on defense. Thirty-three-year-old Hwang Sun-hong struck first to establish a precarious lead, then after halftime thirty-year-old Yoo Sang-chul added a swerving shot into the net. The home crowd of fifty thousand fans, including President Kim Dae-jung, rose to their feet for the rest of the game, clapping steadily to rally their team on to a historic victory. Next, the Reds faced a tough American squad and fell behind, placing tournament hopes in jeopardy. Yet their fan club, the Red Devils, carried on with its rhythmic chant—“Dae-Han-Min-Guk” (Republic of Korea), clap-clap clap-clap clap—drowning out any sound of “USA!” The Reds kept pressing in aggressive runs. Finally, in the closing minutes, a graceful header by twenty-six-year-old Ahn Jung-hwan (more famed for his movie-star looks than late-game heroics) sealed a draw. Screens all across Korea replayed the glorious goal, and popular excitement mounted for the final group match against powerhouse Portugal. From the very start, the stadium shook with the beat of buk drums from the Devils section. The veteran sweeper Hong lofted elegant passes to tee up headers that kept falling just wide of the net, keeping fans on the edge of their seats. Then in the seventieth minute, the tireless twenty-one-year old Park Jisung took a cross in midair, deflected it off a defender, and then drilled a winner through the keeper’s legs. The crowd’s applause rose to a frenzied roar. The team fed off this energy to attack again and again, while the exhausted Portuguese struggled to keep pace.

The Reds won the game and, thereby, won their group. The team had shown steely resolve under pressure. What’s more, it had sparkled with style, dazzling fans with artful passes and acrobatic goals. The host nation that had braced itself for disgrace instead felt exultation.

Every World Cup, the soccer sages of the media soliloquize about a clash of cultures on the field: German industriousness versus Brazilian samba, Italian artistry versus British pragmatism. To Hiddink, these “national character” stereotypes never quite rang true.

Hiddink believed that cultural backgrounds and identities influence players, but not so rigidly that they are limited to one style. He had faith, born of his own experience playing in different countries, that the role of culture is variable, not constant. When he first coached in the Dutch league, he tried importing a star from abroad. Grizzled coaches scoffed that it would never work, a Brazilian would never fit totaalvoetbal. But after experimenting with many minor adjustments in practice, the synergy finally clicked, and the club went on to championships. Then he and others tried bringing the “Dutch style” to Spanish teams supposedly unsuited to it, forging new variants of the style in the process.

Most coaches of the time regarded cultures as something too sacrosanct to touch. Hiddink, in his downtoearth way, saw them as manageable and even malleable. While many coaches believed that national culture was an influence on playing style, few intuited that they could switch on or switch off cultural forces through architecting the cues that surrounded players. While many coaches had sought to harness their team’s organizational culture, few dared to think that they could reprogram this culture through choreographing the players’ social interactions.

After his 2002 run in South Korea, Hiddink repeated the trick, coaching Australia’s Socceroos to its first-time tournament rounds in the 2006 World Cup and then leading underdog Russia to the semifinals of the 2008 Euro Cup. Each time, he managed and molded cultures through cryptic policies and crafty messages. The Socceroos brimmed with athleticism but lacked tactical coordination. Hiddink quashed their boisterous cheering from the bench (which was hampering communication on the field) and imposed strict zones for defenders (so they stopped running all over the field). He reined in selfish stars by invoking the Aussie taboo against “tall poppies.” The Russian squad had a somewhat opposite syndrome of rigid risk aversion, so Hiddink introduced playful routines at practices to loosen them up. He sold them on the totaalvoetbal system by showing them tapes of its earliest incarnation: the pressing defense of a 1960s Moscow coach. Their Russian pride became a force for learning rather than an obstacle to it. Later, Hiddink took over a squabbling squad of international stars at Chelsea, remolded the team culture, and compiled the best coaching record in the English Premier League.

Consistent success—all around the world, at different levels—can’t be just luck. There must be a method to Hiddink’s madness, a means of unlocking talent through selectively evoking and adjusting cultural patterns. Like a horse whisperer, he found ways to summon traits that helped performance and to subdue traits that hindered it. He found ways to gradually reshape each team’s image of itself. And this cultural alchemy—the secrets to the riddle of Hiddink—could make a difference far beyond the soccer pitch.

Around the same time that Hiddink was developing his heretical views about culture on the soccer field, the scientists who study culture were shifting their paradigms in somewhat parallel ways. Not unlike the “old guard” soccer coaches, the older generation of scholars presumed that cultural landscapes were permanent fixtures. Anthropology portrayed Indigenous societies in terms of timeless institutions (e.g., the Haida people hold potlatch feasts before putting up totem poles). Psychology compared individual traits (e.g., achievement-oriented personalities were rife in the US and rare in India). These approaches reduced cultures to stable patterns—age-old institutions or fixed character traits.

However, by the late twentieth century, it became hard to miss that cultural patterns—of societies and of individuals—were in flux. Across the world, societies were evolving as globalized generations developed new lifestyles through selective retention of their parents’ ways and heightened borrowing from other traditions. Individuals were migrating more than ever but not always assimilating—instead, maintaining multiple cultural worldviews that they switched between situationally. Scholars began to appreciate that it was not simply collective institutions or individual psychologies that determined culture, but the interplay between them. Cultural institutions shape the individual’s mind, and the individual’s mind shapes cultural institutions. Culture and psyche are inexorably intertwined.

Over the past two decades, this fusion of anthropology and psychology has produced a new science called “cultural psychology.” Its scholars study many different kinds of cultural groups—from hunter-gatherer clans to corporations to nations—investigating cognitive structures, social structures, biases, and behaviors. It is an interdisciplinary crossroads where scholars from different scientific and cultural backgrounds collaborate. I’ve been fortunate to play a part in the exciting growth of this field. Through the luck of good timing, I’ve conducted some of the pathbreaking studies that shaped the field’s trajectory. A major lesson from the hundreds of studies that I have conducted is that cultural patterns are mutable and malleable, and that with the right tools, we—like Hiddink—can harness them.

Though science is increasingly adopting this dynamic paradigm, the practical world still tends to construe cultural patterns as unchanging (and unchangeable). Politicians reference Appalachia’s “culture of poverty” to imply that economic aid won’t help. Journalists warn of “rape culture on campus,” “gun culture in Texas,” or “drug culture in Hollywood.” Leaders trace their group’s success to its cultural essence: art “runs in the blood” of the Italian people; loyalty is “bred into the bone” by the Marine Corps; innovation is in IBM’s “cultural DNA.” These familiar phrases posit an underlying essence inside members of a tribe that makes them who they are and enables their distinctive talents.

But essentialism gets cultures wrong—sometimes tragically wrong. When a nation, corporation, or team chalks up its success to an immutable essence, it’s a recipe for complacency. The scrap heap of history is full of invincible empires, corporations “built to last,” and perennial champions. Conversely, when we trace an adversary’s sins to immutable imprinting, we become prone to heavy-handed and unhelpful reprisals. After 9/11, US hawks targeted madrassas (Islamic schools that cater to the poor) as “breeding grounds for terrorists,” assuming that jihadi ideals must be inculcated at a mullah’s knee. But radicalism is more a product of resentment than religiosity. None of the attackers attended a madrassa; they studied technical subjects at Western universities (Mohammed Atta studied urban restoration, of all things) and were radicalized then. Likewise, ISIS recruitment came largely from the disenfranchised, not the devout. Its breeding grounds were not madrassas but military prisons and marginalized neighborhoods (revealed by a purchase left behind in a recruit’s London flat: Islam for Dummies). Counterterrorism measures that target whole religions and their basic institutions miss the real sources of radicalization. Worse yet, they play into the hands of extremists by alienating moderates.

Contrary to essentialist views of cultural character as set in stone, people’s cultural conditioning and convictions change over time. We internalize new cultural identities and codes with every new community we join. You may have noticed this in a college freshman who returned home for Thanksgiving with a new persona—listening to new music, spouting new expressions, dressing in a different style, perhaps attesting to different politics. Or you may know someone who joined the army—or joined an ashram—and similarly acquired a fresh identity and outlook. The human brain is wired to automatically encode the ways of the communities that nurture us. We pick up cultural patterns unconsciously, without even trying to. These automatic learning processes play this same role when a group’s changed experiences precipitate new patterns of collective behavior. When Hiddink roomed Reds rookies with veterans, banned Socceroo shouting, and revealed totaalvoetbal’s Russian roots, he was cultivating transformed team cultures.

In addition to learning new cultures, people switch between their multiple cultural mindsets situationally. Walt Whitman said it best: “I am large, I contain multitudes.” A person’s many cultural selves can’t all rule at once; they have to take turns. When our freshman friend returns home, her newfound campus persona isn’t on display every day. It surfaces when her college roommate visits, but not when she hangs out with her childhood friends. Cultural codes spring to the fore of our minds when they are triggered by the situation. This is another key to the riddle of Hiddink. When he transported the Reds to an international training facility abroad, he was placing them in a setting that would call forth their occupational norms as soccer pros and give a rest to their national habits as Koreans. At that stage, the team needed a mindset conducive to learning the unfamiliar tactics required for world-class play.

Tribal will elucidate the hidden dynamics of cultural codes that are drawn upon by Hiddink and other changemakers. I’ve developed frameworks for understanding and managing these dynamics over many years of teaching about related topics at top business schools (a decade at Stanford’s Graduate School of Business in Silicon Valley, another at Columbia Business School in New York City, and shorter stretches at leading institutions in London, Paris, Barcelona, Hong Kong, Singapore, and elsewhere). I’ve worked on the side as a consultant to tech firms, global banks, media conglomerates, and other companies, helping to change organizational cultures, foster diversity, and develop cross-cultural skills. Likewise, I’ve worked with military leaders to develop better models of cultural challenges among allies and adversaries, with the State Department and foreign ministries to understand diversity dynamics, and with the Intelligence Community to trigger the cultural biases of hackers. I’ve worked with public health experts and NGOs seeking to change cultural norms related to health and gender in the developing world. I’ve advised political campaigns about culture-relevant policies and messaging, including the presidential campaigns of Barack Obama, Hillary Clinton, and Joe Biden. I can’t claim to have worked Hiddink-level miracles in these roles, but I do have a wide range of experience putting these ideas into practice.

Despite this work to share insights with practitioners, cultural dynamics are still not very widely understood. While elite corporations are catching on, the tools are just as useful for schools, restaurants, design studios, and many other workplaces where cultural capital matters. Almost everywhere these days, cultural differences can divide, or they can be leveraged for performance and innovation. Many of the relevant research findings about this exist only in technical journals where few can access them. That’s the reason for this book. I’ve tried to leave the jargon behind and convey the practical insights through stories about culture shifters and shapers like Coach Hiddink.

As the tournament rounds began in the 2002 World Cup, South Korea drew top-ranked Italy. The Italians scored early to take the lead and their famed defenders stopped repeated Korean efforts to answer. Yet the ever-swelling section of Red Devils, now wearing face paint and waving flags, rallied their team with propulsive cheering and drumming: “Dae-Han-Min-Guk,” boom-boom boom-boom boom! As the game wore on in the summer humidity, the Reds’ fitness edge began to show, and in the closing minutes the quick reflexes of twenty-three-year-old forward Seol Kihyeon found the net to send the match into extra time. Hiddink kept calling out “Sudden death!” to summon vigilant defense and killer instinct. Meanwhile, the Italians began to fatigue and commit fouls. Finally, in the 117th minute, the striker Ahn found a burst of energy to somehow outjump defender Paolo Maldini and spin a header past the helpless keeper.

The stadium exploded into rapture. Fans of all ages shook outstretched fists, Hiddink’s signature goal celebration. The victory set off shock waves across the country, literally: “When Ahn scored the golden goal, I could feel the apartment building vibrate from the cheering,” a Seoul retiree told reporters. An estimated four million revelers in team regalia filled the streets, soused on soju, chanting “Dae-Han-Min-Guk” as gridlocked cabbies tooted along with their horns (Beep-beep beep-beep beep!). Fans hung signs from their balconies that read “Hiddink for President.” Posters and figurines of the once-reviled foreign coach flew out of the shops. The formerly canceled Samsung ad began airing every hour.

The quarterfinal against undefeated Spain was another taut affair. Gwangju Stadium was a sea of red. Korean fans clapped but also wrung their hands as Spain found the net twice, but the goals were disallowed by referees. The game remained scoreless through ninety minutes and then extra time. Finally, in the penalty shoot-out, Korea’s composure prevailed once again. After the veteran Hong converted the winning kick, he looked up to see forty thousand fans on their feet applauding manically. Unsure of what to do, the team bowed like actors at a curtain call, to one side of the stadium, then the other, to one goal, then the other. The crowd’s roar resolved itself into two syllables—Hee-dink, Hee-dink, Hee-dink!—and the coach finally trotted out to center field. His players lifted him and tossed him high into the air. Thousands of flashbulbs froze the moment. The image fronted every newspaper the next morning. With transformed tactics and traditions, they became the first Asian team to reach the semis!

This wasn’t just a feel-good story for football fans; it became a signal moment for the nation. Spontaneous celebrations broke out in every city and village, a final liberation from the lingering malaise of the economic crisis. Journalists described the team’s triumph as “the greatest moment since the end of Japanese colonial rule.” President Kim went further, calling it “the greatest day since Dangun” (the legendary king who founded Korea four thousand years ago).

The Reds’ run eventually ended in a semifinal loss to Germany, but the chain reaction had gone critical and there was no stopping it. This transformed team was trumpeted in the press as a model for schools, companies, and agencies. The wavy-haired star Ahn, who married Miss Korea, became a celebrity, while Coach Hiddink became something more than that. His statue was erected in parks, and Gwangju Stadium became renamed “Guus Hiddink Stadium.” Journalists compared him to Hendrick Hamel, the seventeenth-century Dutch sailor who introduced Korea to the West. The government emblazoned his visage on a Korean postage stamp, then (in order to make him an honorary citizen) they changed the country’s age-old ethnic restriction: “the conquest of blood-lineage nationalism.” Symbolically and literally, South Korea opened itself up to the outside world. It was a critical step toward the confident, cosmopolitan South Korea that we know today—a cultural exporter whose soap operas delight the Middle East, whose Kpop bands top the charts, and whose films win Oscars for Best Picture.

Hiddink’s coaching policies, intended to sharpen a single team for one tournament, had much broader ripple effects. New social patterns spread from the soccer pitch to the stands, then the streets, and then the institutions of education, business, and government.

This speaks to the power—and also the danger—of cultural change. Culture is not just malleable; it can be labile and sometimes downright volatile. Hiddink never imagined he’d become an icon of Korean cosmopolitanism, but that happened within months of the Cup. Because of the way cultural patterns are cued and encoded, they sometimes spread through domino effects. Hence, changemakers need to understand not just how to initiate changes, but also how changes can take on a life of their own—for better or for worse. To harness these mysterious ripple effects, we need to consider more deeply what culture is and how it affects us. How did humans evolve to connect this way in the first place?

Aristotle called our species “the social animal.” But we are not the only social animal. Wolves run in packs. Penguins huddle together for warmth. Elephants call out to each other when lost.

Humans are not even the most social animal. Ants, bees, and termites put humanity to shame on many metrics of sociality. Myriad relatives live together with seamlessly meshing behavior and collectively care for their young. But while insect colonies are impressively social places, it’s not our kind of social life. Bees always build hexagonal hives, ants march in lines, and termites swarm in zigzag strides. These patterns recur predictably because they are tightly programmed genetically and propelled pheromonally. We humans are more free, less tightly programmed genetically, so our social patterns can be more diverse and dynamic. Every group dances a slightly different dance, and these choreographies change across generations. We still think and act in ways that mesh with others around us, but it is through patterns that are more shaped by nurture, not just nature.

Our closest evolutionary relatives, chimpanzees, have some of this same behavioral freedom. Chimps can choose whether to cooperate or compete with a neighbor. To lock in cooperation, a chimp needs to bond with each chimp in the group through mutual grooming, a time-consuming process. This need for direct friendship limits how large the circle of cooperation can grow. When a chimpanzee troop expands beyond fifty members, cooperation breaks down into clashing factions. Put a hundred unrelated chimpanzees on an island, and the result would be a bloodbath. A chimpanzee Manhattan, with millions of strangers rubbing shoulders, is inconceivable.

Humans, too, cooperate based on kinship and friendship, but we also have more powerful forms of social glue that other species lack. From the early Stone Age, we started evolving specialized brain systems that facilitated sharing knowledge in groups. If someone in your foraging band figured out how to dislodge coconuts from a tree, you would learn by watching, and soon the whole group would share the skill. Then you could work in closer coordination with each other by following this shared script. In this way, groups living in different ecologies developed different pools of common knowledge: different cultures. Members of each group gained increased mutual understanding; even if the topic wasn’t coconuts, the common ground of shared coconut expertise could help in learning other survival-relevant skills. Group membership became increasingly manifest in behavior, making peers more similar, predictable, and sympathetic. Our forebears began to experience the elevating sense of “Us,” an expansion of identity beyond close kinship and direct friendship to a broader group. In these larger clans, they began to highlight their membership through distinctive styles of dress and self-adornment. At the same time, human brains kept evolving to share new kinds of knowledge, such as reputation in these broader groups, all of which further boosted our fitness as social animals. In time, interactions using new forms of knowledge, such as ritual, coalesced across clans to forge broad networks of sharing in mates, resources, and knowledge. Humans began feeling solidarity with these large communities (thousands of other people living in small groups nested within larger groups) held together by the glue of common cultural knowledge. This form of social organization is not a hive or a troop but a tribe.

Surviving through sharing knowledge in these solidaristic, nested groups is tribal living. With apologies to Aristotle, it’s misleading to call humans “the social animal.” We are more accurately “the tribal animal.”

The word “tribe,” however, has taken on considerable baggage. It originated in the Latin term tribus, for the cultural and regional groups that made up ancient Rome. It came into English (and other languages) with biblical translations for the twelve tribes of Israel. By Shakespeare’s time, it referred to the Jewish people, to Germanic clans, and to New World societies. Only during the era of colonialist expansion did “tribe” take on pejorative connotations of primitivism. European explorers had a vested interest in categorizing the Indigenous peoples they met as at different stages of societal development—“savage” or “barbaric” tribes rather than civilized societies. Left behind by the march of history, they needed the civilizing influence of European armies, missionaries, and schools. These categories were politics, not science.

As anthropology developed as a field, it dropped the evolutionary stage frameworks, and the tribe concept came to be used very broadly. Successive efforts were made to clarify the concept structurally in terms of kinship, authority, or continuity—but without definitive progress. As more and more Indigenous peoples were studied, exceptions rose against every structural criterion: tribes without a chief, tribes with members mostly adopted from other groups, tribes that changed their language, religion, or origin story. The evidence from careful ethnographies diverged so sharply from the classical image of tribes with standard structures of leadership, kinship, and tradition that many anthropologists abandoned the tribe concept, surmising that the notion was just a colonialist mirage. Some even abandoned the theory of culture as a driver of behavior, explaining India’s “sacred cows” in terms of soil conditions rather than Hindu myths.

By the late twentieth century, the pervasive wave of cultural change spelled the end for theories of tribes as rigid structures, but it awakened renewed curiosity about cultural evolution. An exciting new strain of theory and research emerged, providing novel explanations of how tribal living originated in our Stone Age forebears and developed across the ages. Human cultural evolution and genetic evolution have been intimately intertwined from the start of our species, and they continue to affect each other. As early humans learned more and more adaptive lessons from experience (eat red berries, not green berries), mutations conferring brain systems for social learning and imitation became adaptive. As a result of these new psychological adaptations, the pools of shared knowledge in human communities became richer, and this cultural evolution then created new selection pressures for further genetic adaptations. And so on and so on. This cycle of enriched cultures and enhanced brains spawned new human species throughout the Stone Age—each one brainier, more cultural, and more cooperative than the previous. This upward spiral of coevolution is nothing less than a new origin story for our kind, one that places tribes and tribal psychology at the center of the plot.

The new science of cultural evolution also sheds light on the complex ways that tribes change across generations. While theories about these processes of cultural evolution are expressed in complex mathematical models, one of the central insights is that cultural transmission hinges on learning processes. A culture evolves as some elements are learned and others are overlooked as the rising generation re-creates the society. Close studies implicate particular biases in social learning. Conformity bias means that widespread customs are more likely to be learned than rare customs. Prestige bias means that those associated with success and status are more likely to be learned and passed on. Anthropologist Lawrence Rosen suggested that the ways tribes evolve may be what best distinguishes them—tribes are best defined not “in their structural manifestations but in the capabilities that allow them to adapt.”

Other quirks of social learning, such as a bias toward continuity with deep tradition, might seem to inhibit cultural change. Yet when hijacked by political movements that mythologize halcyon eras, the drive for continuity can turn into an engine for reactionary change. Some scholars prefer media theorist Marshall McLuhan’s term of “retribalization.” To understand the many twists and turns of cultural change, we can look to the biases of learning within our tribal psychology.

In this book, I peel the onion of our special human talent for sharing with groups to distinguish three layers of “tribal instincts.” They originated in the Stone Age, but we can still recognize these evolved systems in our minds and hearts today. Our sideways glances at classmates, coworkers, and neighbors are part of the peer instinct, as is our impulse to mesh with their patterns in our everyday inferences and actions. Our upward-directed fascination with celebrities, CEOs, MVPs, and other elites comes from the hero instinct, as do our aspirations for glory and our drive to contribute. Our backward-gazing nostalgia is part of the ancestor instinct, as is the comfort we find in traditions and the duty we feel to maintain them. These instincts are like three characters inside every person: the conformist who seeks belonging and understanding, the contributor who dreams of esteem and tribute, and the traditionalist who cherishes continuity. Each of these systems has its fallibilities, but—as we’ll see—each generally guides people in adaptive directions.

The real wonder, though, is what the three systems create in combination. Once all three tribal instincts were in place, in the last hundred thousand years, our forebears began to thrive and to live in recognizably human ways. Within an evolutionary eyeblink, they suddenly had much more sophisticated tools, weapons, arts, and rituals. After millions of years of achingly slow change, cultural complexity began to expand exponentially. The pools of shared knowledge in human communities began to accumulate across generations and adapt to local ecologies. This tribe-level learning (not heightened individual brainpower) is the secret to how our kind adapted to widely differing climates and terrains. Humans became the earth’s dominant species, threatened only by our own success.

In Tribal, I hope to reclaim the original meaning of the word as community enabled by shared culture. This is how humankind first transcended the narrow bonds of kith and kin to accomplish bigger things in clans. And it’s how we later ventured into exchange and collaboration with strangers in the broader networks called “tribes.” In these nested groups, our forebears first felt the empowering experience of access to myriad individuals and ideas, the ongoing experiment that we call society. It was an engine for group change and differentiation. By showing that tribal living is the source of cultural change and progress, I hope to put to rest any lingering association of tribes with stasis and primitivism. Tribal living is what made us truly human.

Just as the word “tribe” largely vanished from anthropology, it began to proliferate in popular parlance. The term and its cognates are used by creedal communities (the Jewish tribe, Amish tribes) and Indigenous nations (the Navajo tribe, the Zulu tribe). Companies chose the term to honor their “power users” (the Mac tribe) and devoted employees (the Zappos tribe). Political analysts applied it to partisan factions. Marketers saw neo-tribes in consumer networks (gamers, environmentalists, extreme sports enthusiasts). Professions, occupations, and vocations found the term felicitous, as did communities formed around shared tastes—Deadheads, surfers, swingers, cyclists, and the like. Likewise for alumni groups, fan clubs, Mardi Gras bands, and Burning Man camps. More than any other English noun, “tribe” captures the sense of meaning and motivation that people find in communities united by shared ideologies, expertise, or aesthetics. I use this concept in search of general principles governing all of these communities—from cave-painting clans to the book clubs, tech firms, and nation-states of today.

Especially in a time of powerful and shifting politics, we shouldn’t ignore our quintessential human capacities to bond with our communities. Nor should we delude ourselves that the thin gruel of rationality and universalism will mobilize people to accomplish desired goals. Guus Hiddink didn’t lead his teams to success through appealing to rational self-interest. He led by harnessing tribal motivations—the pull to mesh with peers, the drive to be a hero, and the ache to maintain traditions. Focusing his players temporarily on their team identity or their occupational identity didn’t eliminate their ethnic and national identities; it ultimately reinforced them. Leaders who can harness tribal impulses can lift a team to greatness and, under the right conditions, this can reverberate in ways that heal a nation. In other words, we shouldn’t fight tribalism—we should channel it.

I write as a convert to the advocacy of tribalism. I used to consider group-related instincts as a detrimental force in human affairs. I was raised (as you may have been too) to see rationality, creativity, and morality as the hallmarks of humanity, and I viewed conformity, status-seeking, and traditionalism as fallibilities. But based on what I’ve learned from decades as a behavioral scientist, I’ve come to see my former humanities worldview as naive, or at least incomplete. Our tribal instincts are not bugs in the system that hinder an otherwise intelligent species. They are the distinguishing features of our kind that enabled its evolutionary ascent—and still drive many of its greatest achievements today. They are not human foibles that hold us back; they are human superpowers that create our distinctive cultures.

In this book, we’ll get to know the three basic tribal instincts one at a time, opening their hoods to see the underlying mechanisms that make them run. That humans are inclined to imitate peers, emulate heroes, and perpetuate traditions is not exactly news. But what will surprise you is just how powerful and pervasive these familiar instincts are. They sustain cultures of very different kinds—religious, regional, occupational, and more. These instincts reveal hidden levers for aligning, inspiring, and emboldening people. And we’ll demystify the paradoxes of change, seeing why many ambitious change initiatives stall out while other movements take off and spread beyond their founders’ wildest dreams.

This book unfolds in several sections. In part I, “Tribal Triggers,” we’ll look back at how our forebears evolved each instinct and gained new social breakthroughs as a result. Because cultural codes can’t all operate at once, they are activated by triggers. Peer, hero, and ancestor codes are triggered by both situational cues and our inner needs. These are the keys that Hiddink turned in his varied training camps to activate or deactivate cultural codes. We’ll see how figures as diverse as Joan of Arc, Martin Luther King Jr., and Singapore’s Lee Kuan Yew used cues to lift groups to face epic challenges. Sometimes triggers arise organically to unlock the cultural strengths needed for a challenge, as when a team of senior-citizen engineers, the Fukushima 50, rallied around the samurai code to save a nuclear plant teetering on the brink of catastrophe.

In part II, “Tribal Signals,” the three layers of culture—peer, hero, and ancestor codes—reveal themselves as not just manageable but also malleable. Hiddink reshaped the Reds’ team norms through changed routines and reshaped the Russians’ sense of tradition by informing them about a Moscow team from generations past. These are examples of how cultural codes get shaped—or reshaped—by informational signals. The unconscious effects of tribal signals elucidate many dramatic and mysterious changes, such as how Brazil defused its population bomb without a family planning policy, how soft-spoken Satya Nadella restored Microsoft to the top of the tech industry, and how Nelson Mandela led the rainbow nation through its collective trauma and into a democratic future.

Part III, “Tribal Ripples,” builds on these previous sections to explore how cultural change spreads more broadly. The opening chapter considers how chain reactions work in models for managing change. A “grassroots movement” is a bottomup sequence of changes, from ordinary people’s habits to collective ideals to public institutions. “Shock therapy” prescribes an opposite, top-down progression. Tribal psychology shows us how each sequence creates ripple effects of change and the conditions to which each strategy is best suited. We’ll see why the grassroots strategy worked for same-sex marriage but not for the Occupy movement. We’ll see why a shock-wave strategy helped Mary Barra jumpstart change at GM but backfired for Ellen Pao at Reddit.

The closing chapter considers unwanted chain reactions in the escalating group conflicts of our day—political, racial, and sectarian. In the past few years, political pundits increasingly blame these pressing problems on toxic tribalism, implying that a primal hate for out-groups has somehow resurfaced to tear our world apart. While it’s an engaging theme that the “Us” instincts inevitably create hostility toward “Them,” it doesn’t square with evolutionary or psychological evidence. A better way to understand escalating conflicts, and the role of evolved psychology therein, is to look for the signature processes of the three familiar tribal instincts, each of which can cycle out of control under certain conditions in dysfunctional ways. Fortunately, our understanding of triggers and signals suggests interventions to break the cycles. To be sure, tribal psychology is part of the problem in many of today’s conflicts—but it can also be part of the solution. We’ll see how some citizen groups are bridging the divide between peers of red and blue persuasions, how heroes like maestro Gustavo Dudamel have catalyzed ethnic inclusion in workplaces, and how interventions that remind Christians and Muslims about themes of tolerance in their scriptures can reverse their defensive responses to threats, allaying the escalation of sectarian violence.

At a time of ethnic strife, pandemics, and climate crisis, our human capacity to act collectively is more important than ever. We must transcend the Manichean paranoia that our greatest evolutionary blessing carries with it an ineluctable curse. Our tribal instincts are our greatest tool for group cooperation—we should not fear them but learn to harness them. They offer some hope to save us from ourselves. Ultimately, this is a book about how we change—together.

Part I

Tribal Triggers

1

Syncing Up

Alone we can do so little; together we can do so much.

—Helen Keller

When mud is just the right consistency, it can stop time in its tracks. In 2007, near Kenya’s Lake Turkana, archaeologist Jack Harris, who had worked for decades at the site, brushed away layers of sand to uncover traces of long-ago life. Indentations in the mud had hardened into stone. Among many tracks of birds and antelopes were some familiar oblong prints: ninety-seven impressions of human feet so well preserved that all the toes were visible. Carbon dating revealed, astonishingly, that these prints had been frozen in time for 1.5 million years. They were the oldest human footprints ever discovered.

These fossilized prints offered a tantalizing glimpse into the life of Homo erectus, who roamed the earth throughout the early Stone Age. While tried-and-true archaeological techniques could identify the species involved, they couldn’t discern what activity the tracks reflected. They could have been left by a band of passing nomads, by one thirsty individual’s repeated water runs, or by any number of other lakeside scenarios.

To plumb this mystery, young scientists flocked to the Turkana site to try new techniques that had been revitalizing the study of human origins. To experts on human anatomy and locomotion, minute structural details of the well-preserved prints spoke volumes. Neil Roach and Kevin Hatala used precise digital measuring tools and 3D modeling software to match prints from the same individuals and simulate the strides connecting them. In a behavioral science approach, they recruited volunteers of different ages and genders from the nearby Daasanach people to walk and run on some lakeside mud. From these reference points, they could identify the sex, age, and height of the paleo pedestrians, as well as their timing and pace. The tracks were created by a group of young men trekking quickly together—the earliest evidence of a human sex-segregated group activity. Tellingly, the group traversed the shore like hunters in pursuit of prey, rather than converging on it like seekers of water. The totality of the Turkana evidence points to an intriguing explanation—a hunting party stalking antelope.

Archaeologists had long noticed antelope bones in erectus living sites, but had no clue how our forebears came by this bounty. Antelopes startle at the slightest sound and sprint away at sixty miles per hour. Not even Usain Bolt could catch one! This early species lacked any weapons that could close the distance. They invented only one tool in their million years on the planet: a handheld chunk of flint used for chopping, pounding, and smashing. This staggering technological stasis gave archaeologists the impression of erectus as little beyond apes in intelligence. Some surmised that they came by their occasional venison as scavengers (by scrounging carrion from the savanna after the big cats had had their fill).

But the Turkana tracks raised a more exalted possibility. The San people of the Kalahari Desert (the world’s oldest tribe) can stalk antelopes through a technique called “persistence hunting.” Several hunters work to separate an animal from its herd and then chase it, track it, and chase it again—repeatedly, until it overheats and collapses (evolution built antelopes to be sprinters, not marathoners). The key to this hunting method is coordinating on the same target; it does no good to chase different antelopes around all afternoon. The hunters must form a shared plan. Biologist and professional tracker Louis Liebenberg proposed that early humans like erectus could have collaborated this way to hunt antelopes. Roach and Hatala’s findings provide supporting archaeological evidence.

The hunting explanation implies that erectus enjoyed a larger leap in brain evolution than previously assumed. Our closest ape relatives, chimpanzees, are impressively inventive but not collaborative. A chimp may figure out how to move logs to feast on the termites underneath, but never do two chimps work together to move a log that is too heavy for one of them. Nor do they ever point to inform a peer about something. This is one reason why they can’t coordinate to hunt antelopes—they can’t point out the intended target. We can’t be sure exactly what the young male humans were doing that day long ago near Lake Turkana, but their tracks tell of a level of teamwork beyond what prior primates could muster.

At later sites, archaeologists found hints of coordinated activity in gathering as well as hunting. In Israel’s Hula Valley, Naama Goren-Inbar excavated a lakeside site where a soil layer from eight hundred thousand years ago shows extensive evidence of human inhabitation. Her team uses laboratory techniques to analyze microscopic bits of plants, bones, and stones. From the elevated presence of botanical fragments in these soil layers (relative to earlier and later layers), they infer the foraging of fifty-five different plant species. This harvest was not just low-hanging fruit, mind you, but also included nuts from tall trees, tubers from deep underground, and even water lilies that blossom far from shore. The sheer range and challenge of their foraging bespeaks coordinated work. The haul even included plants that are inedible unless cooked, suggesting that these erectus women may have also gathered fire—the glowing embers after a lightning strike that could be used to start cooking fires. In 2004 Goren-Inbar’s microscope first discovered bits of charred wood and bone in soil samples, but her team couldn’t be sure they weren’t from natural fires. Three years later, they discovered “phantom hearths,” rings of stone fragments scarred from repeated exposure to fire. A decade earlier, biological anthropologist Richard Wrangham had pondered the evolutionary paradox that erectus brains expanded while their jaws and guts shrank (i.e., an increased demand for calories, yet reduced capacity to supply them) and posited that the advent of cooking could be the explanation. Archaeologists at the time scoffed because no hearths could be seen at erectus sites, but Goren-Inbar’s microscope revealed the smoking gun. We can’t reconstruct these primeval barbecues in full detail, but we can bet that roasting an antelope was not a one-caveman (or cavewoman) job. Not even survivalists like Bear Grylls would try that. For the butchery, fire-building, and browning, you’d want a cooking crew working in close coordination.

A final surprise about erectus involves language. Chimps use gestural signals to communicate fixed messages but lack grammar for combining these into sentences that express novel ideas (likewise, sign-language training experiments succeed in teaching them many words but not in teaching grammar). This shortcoming is understandable because chimps lack the specialized brain structures that we humans use for syntactic processing. This left-hemisphere circuitry is, neuroscientists believe, the reason that 90 percent of humans are right-handed. Interestingly, studies of erectus skeletal asymmetries reveal that they, too, were predominantly right-handed. Paleodental analyses of tooth wear concur: 90 percent stuffed their faces from the right side. This “righty” predominance is not present in chimps or in the australopiths of three million years ago (which immediately preceded the first humans). Its presence in erectus suggests the emergence of syntactic circuitry and capacity, likely a gestural language that built on preexisting signals. Contrary to linguist Noam Chomsky’s long-dominant theory that language evolved recently and discontinuously in a massive mutation, these findings about handedness (among other discoveries) now place it far deeper in the human cultural past.

Footprints, water lilies, fire scars, tooth wear. Separately, such clues are open to various interpretations. But together, they provide converging evidence that our primordial human predecessor has been grossly underestimated. Erectus was not the single-tool simpleton that archaeologists have long portrayed. It was the first hominin to operate in coordinated groups, a critical step toward tribal living. By coordinating—melding minds and meshing actions—erectus groups foraged more efficiently, fed themselves, and forged the solidarity that comes from working in concert. Its evolutionary breakthrough was not walking upright (as its name forever implies) but working as a team. Its great innovation was not the hand axe (which all the textbooks trumpet) but the hunting party, the gathering squad, the cooking crew—and the linguistic communication that made them all possible.

These revelations of erectus teamwork are part of a dawning scientific awareness that humans’ social smarts (and social lives) are more central to our ascent—from prehistory to the present—than previously understood.

Classically, the science of human origins was all about how the body evolved. A famed illustration, entitled The March of Progress, portrays it as a succession of silhouettes: Australopithecus on all fours, then knuckle-dragging Homo habilis, Homo erectus standing more straight, Homo heidelbergensis carrying a crude spear, Homo neanderthalensis with a more fine-tooled club, and then finally the upstanding profile of our own kind, Homo sapiens. It was progress in terms of posture, at least!

Yet even this triumphalist diagram can’t hide that there were trade-offs involved. Across millions of years, our forebears gradually lost apes’ thick fur, sharp fangs, crushing grip, and four-legged speed. This was a lot to lose, survival-wise. Big cats could catch them in one pounce. Cave bears could tear them to shreds. But while they lost their physical defenses, they gained brain size. Apes were already brainiacs compared to other mammals, but humans evolved brains three times larger. These freakishly large thinking organs are “gas guzzlers”: 2 percent of our body weight that consumes 20 percent of our calories. Anything so resource-consuming must have been very helpful—somehow—to survival.

Thoughts don’t leave fossils, so archaeologists didn’t have evidence about how bigger brains helped. Most presumed that hominid brains ballooned to provide greater mastery over the physical environment. That is, chimps evolved big brains so they could navigate large terrains, devise ways of cracking nuts, and find trees with ripe fruit. Early humans developed even bigger brains to avoid quicksand, craft spears, and build shelters. This explanation seemed so self-evident that it remained untested through most of the twentieth century.

It took a scientist versed in both physiology and primatology to test it. For every primate species, from tiny spider monkeys to hulking mountain gorillas, Robin Dunbar calculated an “encephalization index”—brain size as a proportion of body size. Then he analyzed whether braininess is related to how these primate species live and survive—their range, diet, group size, mating habits, and so forth. The correlations revealed, surprisingly, that brainier species don’t cover more territory, crack more nuts, or eat more fruit. But they do mate more judiciously, maintain longer “pair bonds,” and cooperate in larger groups. Brainier primates have more complex social lives. Dunbar proposed a new theory: big brains evolved for mastery of the social environment, not mastery of the physical environment.

This “social brain hypothesis” gained further traction as behavioral scientists adopted neuroscience tools for imaging brain activity. A wave of revolutionary studies hooked people up to fMRI machines while they engaged in different kinds of thinking tasks. They found that social judgments (e.g., reading a person’s intentions, or anticipating their feelings) are handled by different parts of the brain than judgments about the physical world. The forebrain regions that handle social thinking (e.g., the prefrontal cortex) are the ones that expanded most dramatically in the evolution from apes to us.

Then, in the mid-aughts, another offbeat study sealed the case for social aptitudes as our species’ signature strength. An expert on both child cognition and primate cognition, Michael Tomasello decided to conduct the ultimate standardized test. His lab administered a broad battery of aptitude tests to three groups of test-takers: humans, chimps, and orangutans. The humans were preschoolers, so education wouldn’t give them an edge. The tests were administered as puzzles with food treats as rewards. Perhaps this seems a foolish study—surely humans (with much bigger brains) were much smarter across the board? Surprisingly not. On standard tests of cognitive capacities relevant to physical things (e.g., object permanence, shape rotation), chimps didn’t differ from humans, and orangutans were not far behind. But on tests of social cognitive capacities (e.g., inferring intention from an action, learning a skill from a demonstration), humans performed almost perfectly, whereas the chimps and orangutans floundered. For instance, after watching someone pop open the end of a plastic tube to access the treat inside, all of the human toddlers reproduced this method to solve the puzzle. Chimps and orangutans watched the same demonstration but somehow missed the lesson. When given their turn, they tried to break the tube or bite it open, grimacing with frustration at their inability to get the treat.

It’s easy to take social inferences for granted because they come so naturally to us. We can read intentions and reproduce demonstrated actions effortlessly. But they are computationally complex problems for which our brains just happen to have dedicated chips. Our innate wiring for social cognition largely consists of several tribal instincts: the human-specific adaptations that evolved to enable our distinctive form of social living. As we’ll see, three major tribal instincts evolved at different stages of the Stone Age. They helped our forebears learn the ways of their group and act upon them. In more academic terms, they encode group patterns and then enact these patterns. You can think of these systems as both a radar that continually scans the social environment and an autopilot that helps you steer safely through it.

Tribal instincts changed the human experience of group living in several ways. First, they accelerated the acquisition of learned skills. With tribal instincts, I don’t have to rely on effortful trial-and-error experience, as I can pick up many skills through observation. If I see a peer knocking fruit from a high branch with a stick, my brain encodes this action so that when I am next in the situation I feel impelled to try it. If other group members witness me, they can pick up the skill in the same way, and so on and so on, until everyone in the group knows it. As a practice becomes common to a group this way, it takes on meanings and functions beyond its original instrumental value. It’s what “we” do. It contributes to similarity within the ingroup and distinctiveness from out-groups, heightening feelings of connection and loyalty. It also powerfully enables collaboration. When I learn a skill through observing groupmates, the code is tagged in my head as shared by the group. Because I know that they know it, I can anticipate their moves, understand their intentions, and make complementary contributions. The power of such known knowns has been discovered independently in many different fields—linguists call it “common ground,” game theorists call it “common knowledge,” cognitive scientists term it “second-order knowledge,” and psychologists prefer “metacognition.”

This transformative tribal wiring—honed by a million years of evolution—put our Stone Age forebears on the path to living in highly cultural and highly collaborative groups. You may have heard the well-worn twentieth-century notion that our forebears knew only small bands of close relatives who lived and foraged together (like a chimpanzee troop)