Ancient cave painters sometimes created elaborate images in dark, narrow passages navigable only with artificial light. Hardly optimal conditions for an artist. So why would Picassos of the Late Stone Age even attempt to draw in such poorly lit, hard-to-reach spaces? Because they knew the environments would deprive them of oxygen and get them high, according to a new study.
They were "motivated by an understanding of the transformative nature of an underground, oxygen-depleted space," archaeologists from Tel Aviv University say in the study, which appears in the latest issue of Time and Mind: The Journal of Archaeology, Consciousness and Culture. The oxygen deprivation helped them tap their deepest, most visceral levels of creativity and connect to the cosmos, the research suggests.
In many Indigenous societies, actively connecting with the cosmos and environment is considered key to individual and communal well-being and adaptation. "It was not the decoration that rendered the caves significant," the study says. "Rather, the significance of the chosen caves was the reason for their decoration."
When the body's mandatory blood-oxygen concentration falls below a certain level, hypoxia follows. It's a potentially life-threatening state that can cause a range of biological and cognitive changes, including increased dopamine, hallucinations and euphoria. The researchers believe artists from between 14,000 and 40,000 years ago lit their way through caves' interior depths with flickering torches knowing the fire would reduce oxygen levels in the already poorly ventilated spaces. Some art was found in areas that involved climbing steps, crossing narrow ledges and even shafts that descended several meters deep.
The researchers studied decorated caves first discovered in Western Europe in the 19th century to further interpret the enduring mysteries of cave art and explore what motivated these very early artists. Many of the images were painted in black and red, or engraved on soft walls or hard surfaces. They mostly depict animals, but also hand stencils, handprints and abstract geometric signs.
Not all cave art appears in deep, dark recesses -- some decorates walls near entrances or shelters. But it was the art in remote cave areas not used for daily domestic activities that most intrigued researchers like Yafit Kedar, a Ph.D. candidate in Tel Aviv University's department of archaeology.
She's the one who theorized the artists deliberately induced hypoxia to achieve an altered state of consciousness.
To research her hypothesis, Kedar and her fellow scientists simulated the effect of torches on oxygen concentrations in closed spaces such as those in the Upper Paleolithic caves. They found that oxygen levels in narrow passages or halls with a single passage quickly declined to below 18%, the level known to induce hypoxia in humans.
It's been a good year for cave art, which has much to tell us about how our forebears lived and thought. Earlier this year, researchers identified an image of a warty pig from 45,500 years ago that they believe to be both the world's oldest cave painting and earliest known surviving depiction of the animal world.
The past several years have brought other exciting discoveries of ancient drawings, though nonfigurative, including one found in South Africa from 73,000 years ago that resembles a hashtag and another from between 2100 and 4100 BC that may show humans' wonder at a stellar explosion.