What does the oldest known art in the world tell us about the people who created it? Images painted, drawn or carved onto rocks and cave walls—which have been found across the globe—reflect one of humans’ earliest forms of communication, with possible connections to language development. The earlest known images often appear abstract, and may have been symbolic, while later ones depicted animals, people and hybrid figures that perhaps carried some kind of spiritual significance.

The oldest known prehistoric art wasn't created in a cave. Drawn on a rock face in South Africa 73,000 years ago, it predates any known cave art. However, caves themselves help to protect and preserve the art on their walls, making them rich historical records for archaeologists to study. And because humans added to cave art over time, many have layers—depicting an evolution in artistic expression.

In 2018, researchers announced the discovery of the oldest known cave paintings, made by Neanderthals at least 64,000 years ago, in the Spanish caves of La Pasiega, Maltravieso and Ardales. Like some other early cave art, it was abstract. Archaeologists who study these caves have discovered drawings of ladder-like lines, hand stencils and a stalagmite structure decorated with ochre.

Neanderthals, an archaic human subspecies that procreated with Homo sapiens, likely left this art in locations they viewed as special, says Alistair W.G. Pike, head of archaeological sciences at the University of Southampton in the U.K. and co-author of a study about the caves published in Science in 2018. Many of the hand stencils appear in small recesses of the cave that are hard to reach, suggesting the person who made them had to prepare pigment and light before venturing into the cave to find the desired spot.

The markings themselves are also interesting because they demonstrate symbolic thinking. “The significance of the painting is not to know that Neanderthals could paint, it’s the fact that they were engaging in symbolism,” Pike says. “And that’s probably related to an ability to have language.”

The possible connection between cave art and human language development is something Shigeru Miyagawa, a professor of linguistics and Japanese language and culture at MIT, theorized about in a 2018 paper he co-authored for Frontiers in Psychology.

“The problem is that language doesn’t fossilize,” Miyagawa says. “One of the reasons why I started to look at cave art is precisely because of this. I wanted to find other artifacts that could be proxies for early language.”

One particular thing he’s interested in is the acoustics of the areas where cave art is located, and whether its placement had anything to do with the sounds people could make or hear in a particular spot.

Over time, cave art began to feature human and animal figures. The earliest known cave painting of an animal, believed to be at least 45,500 years old, shows a Sulawesi warty pig. The image appears in the Leang Tedongnge cave on Indonesia’s Sulawesi island. Sulawesi also has the first known cave painting of a hunting scene, believed to be at least 43,900 years old.

These Sulawesi cave paintings demonstrate the artists’ ability to depict creatures that existed in the world around them, and predate the famous ​​paintings in France’s Lascaux cave by tens of thousands of years. The Lascaux paintings, discovered in 1940 when some teenagers followed a dog into the cave, feature hundreds of images of animals that date to around 17,000 years ago.

Many of the images in the Lascaux cave depict easily -recognizable animals like horses, bulls or deer. A few, though, are more unusual, demonstrating the artists’ ability to paint something they likely hadn’t seen in real life.

The Lasacaux cave art contains something like a “unicorn”—a horned, horse-like animal that may or may not be pregnant. Another unique image has variously been interpreted as a hunting accident in which a bison and a man both die, or an image involving a sorcerer or wizard. In any case, the artist seems to have paid particular attention to making the human figure anatomically male.

In North America, rock and cave art can be found across the continent, with a large concentration in the desert Southwest, where the arid climate has preserved thousands of petroglyphs and pictographs of ancient puebloan peoples. But some of continent's the oldest currently known cave paintings—made approximately 7,000 years ago—were discovered throughout the Cumberland Plateau, which stretches through parts of Kentucky, Tennessee, Alabama and Georgia. Indigenous peoples continued to create cave art in this region all the way into the 19th century.

Many of the Cumberland Plateau caves feature a spiritual figure who changes from a man into a bird, says Jan F. Simek, an archaeology professor at the University of Tennessee, Knoxville, who has studied and written about cave and rock art in the region.

It’s clear from the way that some paintings in the Cumberland Plateau caves are grouped that the artists were telling a story or narrative.

“There’s a cave that’s actually relatively early in time in middle Tennessee that has a number of depictions of a boxlike human creature…paired with a more normal-looking human,” he says. “And they are interacting with each other in relation to what appears to be a woven textile.”

He continues, “there is a narration there, there’s a story there, even though we don’t know what the story is.”

That’s true of a lot of cave art as well. Even if archaeologists can’t tell what an early artist was saying, they can see that the artist was using images purposefully to create a narrative for themselves or others.