By Pat Anson, PNN Editor

The popular image of Neanderthals is that they were brutish and primitive hunter-gatherers who scratched out an existence in Eurasia 500,000 years ago. That may be a bit unfair. Anthropologists say Neanderthals were more intelligent than we give them credit for, lived socially in clans, and took care of each other. They also co-existed for tens of thousands of years with modern humans, competing for food and sometimes interbreeding before the Neanderthals were driven to extinction.

Neanderthals may have had the last laugh though, because we’ve inherited a gene from them that makes some of us more sensitive to pain, according to a new study published in the journal Current Biology. The gene affects the ion channel in peripheral nerve cells that send pain signals to the brain.

“The Neandertal variant of the ion channel carries three amino acid differences to the common, ‘modern’ variant,” explains lead author Hugo Zeberg, a researcher at the Max Planck Institute for Evolutionary Anthropology in Germany. “While single amino acid substitutions do not affect the function of the ion channel, the full Neandertal variant carrying three amino acid substitutions leads to heightened pain sensitivity in present-day people.”

Zeberg and his colleagues say about 40% of people in South America and Central America have inherited the Neanderthal gene, along with about 10% of people in East Asia. Using genetic data from a large population study in the UK, they estimate that only about 0.4% of present-day Britons have the full Neanderthal variation of that specific gene.

“The biggest factor for how much pain people report is their age. But carrying the Neandertal variant of the ion channel makes you experience more pain similar to if you were eight years older,” said Zeberg.

The Neanderthal ion channel in peripheral nerves is more easily activated by pain, which may explain why modern-day people who inherited it have a lower pain threshold. Exactly how the gene variation affected Neanderthals back in the day is unknown.

“Whether Neandertals experienced more pain is difficult to say because pain is also modulated both in the spinal cord and in the brain,” said co-author Svante Pääbo. “But this work shows that their threshold for initiating pain impulses was lower than in most present-day humans.”

It’s possible the heightened sensitivity to pain acted as an early warning system for Neanderthals, alerting them to injuries and illnesses that needed attention. Neanderthals lived a hard life. About 80% of Neanderthal remains show signs of major trauma from which they recovered, including attacks by bears, wolves and other large animals.

Neanderthals made extensive use of medicinal plants. The remains of a Neanderthal man in Spain with a painful tooth abscess showed signs that he chewed poplar tree bark, which contains salicylic acid, the active ingredient in aspirin.