We all know stories are powerful. And some themes and subject matter are evergreen: friendship is celebrated in Don Quixote as well as in the Frog and Toad books. Mating partners and social standing figure equally in Pride and Prejudice and the eleventh-century Japanese saga The Tale of Genji. “Widespread infatuation with a tale involving brother-sister incest, adultery, and fractious ­kingdoms” describes Game of Thrones and the l­egends of King Arthur.

But why do stories matter? Why do certain types of them continue to hook us? Why are stories — especially those encountered in childhood — so influential? As literary scholar Jonathan Gottschall points out: “Nothing so central to the human condition is so incompletely understood.”

The roots of narrative do extend far into our past. The first written story is the thirty-eight-hundred-year-old Epic of Gilgamesh, about a Sumerian king, his beloved sidekick Enkidu, and Gilgamesh’s search for immortality after his friend’s death. Gilgamesh is the oldest known bromance and the oldest known quest tale. Some oral narratives are likely even more ancient. The Klamath people of northern California and southern Oregon tell a legend about a fight between the Spirit Chief and the Chief of the Underworld. The Chief of the Underworld causes a mountain to explode, throwing fiery lava upon the people. After the Spirit Chief causes the mountain to collapse on top of his foe, medicine men sing for rain to put out the fires, turning the caldera into Crater Lake. This story describes geological events that happened over seven thousand years ago.

Or consider a tale told by the Aboriginal Gunditjmara people of Australia. According to legend, a local volcano, Budj Bim, was formed from a giant who spat liquid fire. Since Budj Bim last erupted thirty-seven thousand years ago, this might be the world’s oldest story. But if you’d really like to follow me out on a limb, Indigenous people on the island of Flores in Indonesia tell legends about small, hairy forest-dwellers called ebu gogo. In 2004 scientists excavating a cave on Flores discovered the remains of Homo floresiensis, a three-and-a-half-foot-tall hominin nicknamed (inevitably) the Hobbit. The Flores Hobbits have been extinct for fifty thousand years. Is it possible the last Hobbits overlapped with Flores’s first humans, inspiring tales passed down for fifty millennia?

We usually think of story as a product of culture — Klamath or European or Gunditjmara — rather than a product of biology. We forget that our minds, as much as our opposable thumbs, have deep evolutionary roots. As novelist Ian McEwan points out, when observing chimpanzees and bonobos “one sees rehearsed all the major themes of the English nineteenth-century novel: alliances made and broken, individuals rising while others fall, plots hatched, revenge, gratitude, injured pride, successful and unsuccessful courtship, bereavement and mourning.”

A keen interest in conflict (story’s number-one ingredient) and a resulting emotional arousal (story’s number-two ingredient) are the basic factory settings for both humans and our close evolutionary cousins. This makes Darwinian sense. If you’re a primate living in a small band, cooperating and competing with others, social interactions matter. Any fight or hookup might affect your status and your ability to attract allies and mates. Your social environment, as much as your physical environment, determines whether you survive and reproduce.

But even captive chimps and bonobos that have been taught sign or symbol languages don’t create narratives. Their communications are limited to simple requests and declarative statements. Though we share a common ancestor with chimps and bonobos, the human line followed a different path that eventually led to extra-large brains and sophisticated spoken language. The advantages of language are obvious: we could discuss yesterday’s hunt, or our current hunt, or where to hunt tomorrow. Language made it easier to teach our children complex tasks like fire-starting and spear-making. Still, language could’ve remained a useful tool without spawning the Mahabharata. So why does the Mahabharata or Beloved or Where the Wild Things Are exist?

Storytelling is universal in human cultures. As anthropologist Michelle Scalise Sugiyama notes, our narratives all have the same basic structure: at least one character, a setting, a sequence of events, causal connection, goal-oriented action, and resolution. And small children spontaneously engage in pretend play — a basic kind of storytelling — at around age two. To say that an interest in story is hard-wired in humans is not to say it is instinctual, like the suckling of a ­newborn. But it seems our brains are primed to embrace stories. Studies show that when we become immersed in a narrative we get a jolt of oxytocin, a hormone that enhances group trust and cooperation.

The universal nature of storytelling suggests the behavior has a genetic component. A genetic component, in turn, suggests there’s something about storytelling that aided the survival of our ancestors.

Anthropologists seeking to explain why we tell stories often study modern hunter-gatherer societies. Homo sapiens first appeared about three-hundred-thousand years ago in Africa, while agriculture was invented approximately eleven thousand years ago, so the hunter-gatherer lifestyle represents a whopping ninety-six percent of our existence. In our hunter-gatherer days, as evolutionary biologist David Sloan Wilson points out, “a library was a group of people willing to talk to you.”

At first glance the “story libraries” of modern hunter-gatherers are mostly charming little just-so stories acted out by gods and talking animals. Dig a little deeper and you discover what Sugiyama calls the forager curriculum, a compendium of vital ecological knowledge.

Take, for example, a Klamath story about Crow. Winter is harsh and food is scarce, but Crow refuses to share roots gathered by his wife with his wife’s starving brothers. When his brothers-in-law net fish and generously share with Crow, he nearly chokes on a fish bone and is eventually banished for his self-centeredness. This deceptively simple tale contains practical and moral guidance (sharing helps us survive food shortages), a warning (violate social norms and you’ll be punished), and an attention-getting element (talking crows) that make the story memorable.

Or consider star mythology. A random arrangement of stars can be transformed into a familiar object by giving it a backstory (“Orion was a hunter”). Once you have a story map in your head, you’re better able to navigate desert, sea, or tundra. Celestial objects can also be used to predict seasonal change, which in turn predicts when certain foods will be available.

“The Origin of the Kiawa Rocks,” a tale told by the Miskito and Sumu people of Nicaragua and Honduras, describes a fight between a god and an evil spirit. Along the way it works in natural history information about parrots and boa constrictors, landmarks for navigating local waterways, and a warning about a dangerous stretch of river. Aboriginal Australians, of course, are justifiably famous for their songlines, creation myths that encode landscape information so detailed they can be used as route maps.

A study of Agta hunter-gatherers in the Philippines found that Agta tales address social behavior, with morals emphasizing cooperation and egalitarianism. Skilled storytellers were also preferred partners and had more children than other members of the group. The Darwinian benefits of being such a rock star are obvious.

This is not to say that hunter-gatherers transmit most information through fiction. Far from it. A study of !Kung Bushmen in Botswana reported that ninety-four percent of daytime conversations were “not story,” meaning jokes, gossip, complaints, or discussions about practical matters such as economics or how to treat sickness. But once the sun went down, eighty-five percent of conversations involved storytelling. And if you’re going to keep people from nodding off around the campfire, it pays to employ attention-getting techniques.

Most stories, whatever their cultural origin, involve violations of social norms. Yes, we’re back to those essential story elements: conflict and emotional arousal. We’re riveted by rule-breaking and want rule-breakers to face justice. If you’ve committed the sin of dragging your enemy’s corpse behind your chariot, we want there to be consequences, even if you’re Achilles. (Maybe especially if you’re Achilles.) Conflicting rules are even more engrossing — do we adhere to the law of the land or follow our moral compass? In The Giver, for example, Jonas must reject his society’s Orwellian strictures in order to save Gabriel. We also like to see virtue rewarded, particularly after it’s been rigorously tested. Frodo leaves Middle-earth for the Undying Lands. ­Cinderella gets her happily-ever-after. Wilbur avoids becoming bacon and Charlotte fulfills her arachnid destiny.

Stories are always edited versions of reality. They are patterns plucked from a random and chaotic world that give us the illusion of understanding and control. When a story-world restores the moral order, we all breathe a sigh of relief. Real life isn’t as accommodating.

In storytelling, there’s one thing even more attention-getting than violating a social norm: violating the laws of reality. That’s why so many stories — ancient and modern — include anthropomorphic animals, superhumans, gods, djinns, ghosts, witches, and the like. To be successful, these story elements must be strange, but not too strange. Research shows that people from diverse cultures prefer supernatural elements that are minimally counterintuitive. Luke Skywalker can move things with his mind. Got it. Mermaids are women with fishy tendencies. We can imagine that. What about a flowering brick that only exists on Tuesdays? Ridiculous. Give us talking bears from Narnia.

Monsters are a special subcategory. We reached the top of the food chain comparatively recently in our evolutionary history, so it’s no wonder descriptions of predators with sharp teeth make our hearts race. Combine sharp teeth with an unnatural appearance and you’ve got a monster. Many cultures use stories about monsters lurking in dangerous places (caves, swamps, dense forests) to deliberately scare the bejesus out of children as a way of keeping them safe. Traumatized, but safe.

These days we tend to view stories as pleasant distractions. Reading The Velveteen Rabbit to our kids, heading out to see a rom-com on date night, watching the mindless mini-dramas of Say Yes to the Dress after an exhausting workday. But the evolutionary roots of storytelling lie in survivalism, not escapism. Experience was hard-won and stories were cheap. Through stories, the collective wisdom of centuries (or even millennia) could be passed to future generations. Those individuals and groups most adept at packaging pro-social lessons and ecological knowledge into memorable narratives were more likely to get through the bad times.

Unfortunately, storytelling can also be a Dark Art worthy of a term’s study at Hogwarts. Stories can bring us together, giving us common values, common purpose, and a common identity. Stories can also demonize and ­dehumanize those who don’t share our values, purpose, or identity. For every protagonist there’s usually a villain. The science behind storytelling can help alert us to some of these negative effects.

Remember how we get a jolt of oxytocin during narrative immersion? ­Oxytocin increases trust and cooperation within our social group. It also makes us protective of our group versus outsiders. As neuroendocrinologist ­Robert M. Sapolsky writes: “Oxytocin, the luv hormone, makes us more prosocial to Us and worse to everyone else.”

Perhaps the trick is to harness storytelling’s ability to expand who we include in “Us.” The best stories spark empathy and wisdom. They allow us to see the world from another’s viewpoint (including nonhuman viewpoints), show us the consequences of actions, and model the values we hope to emulate. “Just as flight simulators allow pilots to train safely,” writes Gottschall, “stories safely train us for the big challenges of the social world.”

Though we no longer necessarily need stories to help us survive winter or navigate rivers, storytelling remains central to the human experience. Whether told by firelight in the shelter of a cave or delivered by a streaming service, stories touch us and mold us. They offer order and meaning. And the most important stories, by far, are the ones we choose to tell our children.

From the March/April 2023 issue of The Horn Book Magazine.