Where would a person make a prehistoric rock drawing today?

For thousands of years, petroglyphs of beasts were made in caves in Europe and beyond. Most are known from Europe, with the famous Chauvet Cave (c. 32,000 years old) and the Lascaux Cave (c. 20,000), but the oldest known drawing comes from Borneo: a 45,000-year-old boar in the Leang Tedongnge -cave.

But why did hunter-gatherers often make those striking drawings in poorly lit caves? Ever since the first discoveries of ancient rock paintings 150 years ago (in Altamira, Spain), many great theories have been circulating in science. The drawings could be part of some kind of hunting magic or the drawings could be the images of shamanic visions, the drawings could even be a reflection of deep societal structures, such as the opposition between male and female. None of those theories are widely accepted, and according to three authors of a recent piece in Scientific Reports such ‘umbrella explanations’ also make little sense for a phenomenon that spans many areas and enormous time spans.

Human tendency

The archaeologists Izzy Wisher and Paul Pettitt (a well-known rock art expert) and the psychologist Robert Kentridge therefore argue for a more context-sensitive and psychological explanation for the special drawings. And they immediately put their words into action by presenting a small study with fourteen test subjects who were allowed to look around part of the El Castillo cave in Spain in a virtual reality environment. In the outcome of that study they see a tentative confirmation that pareidolia, the universal human tendency to create complete images from fragmentary elements, must have played a role in the formation of the petroglyphs.

A classic case of pareidolia is that almost every person sees a face in two dots with a line underneath. Things were more subtle in the virtual reality cave of Wsiher et al. Most of the test subjects had virtually no knowledge of rock art, but among them were two anonymous rock art researchers who were unfamiliar with the Castillo Cave. In the VR version of the Castillo Cave, the original petroglyphs of four rock walls had been erased and the test subjects were instructed to look precisely there and, in the light of their virtual flickering Ice Age light, ask themselves: is this wall suitable for something on it? to draw and what would you draw, and why?

As an Ice Age education, they had been shown a number of modern images of Ice Age animals such as horse, reindeer, deer, mountain goat and mammoth – images that must also have been in the imagination of Ice Age hunters. On two walls, most subjects responded to the same cracks and other rock features that had been used by the Ice Age artists to draw an animal around them. In one of the ‘panels’, nine out of fourteen indicated that they clearly saw an animal belly line in a particular crack, just as rock visitors had seen and used for a bison drawing thousands of years earlier.

The researchers emphasize that their research is just the beginning of using this VR technique to determine the importance of ‘pareidola’ for Ice Age art. The same researchers, in another recent study in the Cambridge Archaeological Journal, found in two other Spanish caves that a large majority of the petroglyphs there were clearly influenced by the properties of the rock wall on which they were placed.