Smithsonian.com

Modern humans may have used art to maintain ties between social groups. Traveling between distant social groups may have led to better spatial reasoning, a new study suggests. Image courtesy of Flickr user mharrsch

Poor Neanderthals. Every time anthropologists acknowledge that these “brutes” were more sophisticated than previously thought, researchers come up a new reason why our closest cousins were inferior. This time it’s their lesser navigation skills. A recent study suggests that modern humans’ greater spatial reasoning may have given them an edge over Neanderthals.

Our spatial abilities is just one part of a multi-step explanation of the Neanderthals’ downfall that Ariane Burke of the University of Montreal in Canada lays out in Quaternary International. She begins with an observation. Neanderthal groups lived in small territories but moved around a lot within their home areas to find all of the food and raw materials they needed. When modern humans moved into Eurasia, they brought a new style of social organization. Different groups over an extended region were interconnected through social networks, like people today. The shuffling of people between groups helped keep group size matched to available resources, Burke argues. (How does she know these social networks existed? She suggests variation in art and other symbolic material culture found in the archaeological record is evidence of social identities, which helped groups maintain social ties.)

By living in small areas, Neanderthals may not have needed advanced “wayfinding” skills, as Burke puts it. Remembering landmarks may have been their best navigation strategy. But because humans were part of large, extended social networks—and may have frequently traveled to less familiar areas—they probably needed more generalizable spatial abilities to make mental maps of the environment. Thus, specific spatial skills may have been selected for, such as improved spatial perception and the capacity to mentally rotate objects. Burke argues that the selective pressure to improve these skills would changed the brain, “widening the cognitive gap” between modern humans and Neanderthals. In turn, improved spatial navigation enabled modern humans to quickly colonize new areas.

Burke says later Neanderthals in Western Europe might have switched to a similar type of social organization in response to a shrinking geographic range due to encroaching humans (again, this idea is based on art and other symbolic culture found at some Neanderthal sites). So Neanderthals might have been on a path toward better spatial reasoning and enhanced cognition. But it was too late. They couldn’t keep up with modern humans.

This scenario reminds me of a study published last year on human and Neanderthal ranging patterns. It came to a different conclusion about the Neanderthal extinction. According to a team led by Michael Barton of Arizona State University, Neanderthals and humans both lived in nomadic groups that roamed over small territories. But as climate changed and resources became sparse, both species started to set up base camps and make longer but more targeted trips across the environment to find food. Because Neanderthals and humans were traveling over greater distances, they met each other more often and probably mated more. Under this scenario, Neanderthals eventually died out because they blended into the human population. This wasn’t because humans had superior intellect of any kind—their numbers were just greater and that’s why they took over. Barton’s team came to these conclusions by looking at changes in patterns of tool-making over time.

I’m not in a position to say which explanation is right. Maybe neither is. But it’s fun to think about the Neanderthal extinction in new ways.