Neanderthal Genes Linked to Pain Sensitivity

If you have a lower threshold for pain than your friends or family, the reason might be hiding in your ancient ancestry. Recent scientific breakthroughs have identified a direct link between DNA inherited from Neanderthals and heightened sensitivity to physical pain in modern humans. This discovery provides a biological explanation for why pain perception varies so wildly from person to person.

The Discovery of the "Pain Gene"

The connection between ancient hominids and modern pain was established by researchers at the Max Planck Institute for Evolutionary Anthropology in Germany and the Karolinska Institutet in Sweden. The study, led by Hugo Zeberg and Nobel Prize winner Svante Pääbo, focused on a specific gene known as SCN9A.

This gene is responsible for encoding a protein called Nav1.7. This protein acts as a sodium channel, which is crucial for the transmission of pain signals. Think of these channels as gates on the surface of your nerve cells. When you touch a hot stove or stub your toe, these gates open to let sodium flow into the nerve cell, triggering an electrical impulse that travels to your brain and registers as “ouch.”

Through analyzing data from the UK Biobank—which holds genetic information for nearly half a million people—the researchers found three specific mutations in the SCN9A gene that are distinct to Neanderthals:

• M932L
• V991L
• D1908G

These variants were found in high-quality Neanderthal genome samples initially recovered from caves in Croatia and Russia.

How the Variant Alters Sensation

The Neanderthal version of the Nav1.7 channel functions differently than the standard modern human version. In individuals carrying these ancient genetic variants, the sodium channels are more easily activated.

Because the threshold for activation is lower, the nerves are “hyperexcitable.” It requires less stimulation to trigger a pain signal. While this does not mean a gentle touch feels like a punch, it does mean that a sharp prick or extreme temperature will register as painful sooner and more intensely than it would for someone without the gene.

The study quantified this sensitivity. Participants in the UK Biobank study were asked to report their pain levels regarding various everyday experiences. Those carrying the Neanderthal variants were approximately 7% more likely to report experiencing pain in their daily lives. In biological terms, the researchers compared the effect to “eight years of aging,” meaning the gene makes a 30-year-old’s pain reception function closer to that of a 38-year-old.

Who Carries These Genes Today?

Because modern humans interbred with Neanderthals approximately 50,000 to 60,000 years ago, fragments of their DNA remain scattered throughout the current human population. However, the distribution of this specific pain-sensitizing gene is not uniform across the globe.

• Europe: The variant is relatively rare, present in less than 1% of the population.
• Asia: It is also uncommon in most East Asian populations.
• The Americas: This is where the variant is most prevalent. It is found in high frequency in populations with significant Native American ancestry. In some populations in Central and South America, up to 50% of people carry the Neanderthal version of the ion channel.

This distribution suggests that the gene survived through distinct migration patterns as humans moved out of Africa, mixed with Neanderthals in Eurasia, and eventually crossed the Bering Strait into the Americas.

The Evolutionary Paradox: Why More Pain?

Evolution usually selects for traits that help a species survive. At first glance, being more sensitive to pain seems like a disadvantage. However, scientists argue the opposite might be true for survival in the Pleistocene era.

Pain acts as a warning system. It teaches you what to avoid. For Neanderthals living in harsh, cold environments full of large predators and rough terrain, a heightened sensitivity to injury could have been a survival mechanism. If you feel pain more acutely, you are less likely to ignore an injury or repeat a dangerous action.

In a world without antibiotics or surgery, a small infection or a broken bone was often a death sentence. Therefore, those who were hyper-cautious due to high pain sensitivity may have lived longer and had more offspring, passing this “hyperexcitable” gene down the line.

Implications for Modern Medicine

Understanding the SCN9A gene and the Nav1.7 channel is changing how pharmaceutical companies approach pain management. Currently, many painkillers (like opioids) target the central nervous system, which can lead to addiction and cognitive side effects.

By focusing on the Nav1.7 channel specifically, researchers hope to develop drugs that block pain signals at the source—the peripheral nerves—rather than dampening the brain’s response.

• Personalized Medicine: Knowing a patient carries the Neanderthal variant could help doctors tailor anesthesia dosages or pain management plans after surgery.
• Non-Addictive Alternatives: Drugs that specifically inhibit the Nav1.7 channel could offer powerful pain relief without the addictive properties of opioids.

This research moves pain from a subjective complaint to an objective, genetic reality. It confirms that when two people experience the same injury differently, it is not a matter of “toughness,” but largely a matter of biology.

Frequently Asked Questions

Can I get tested for the Neanderthal pain gene? While standard commercial DNA kits (like 23andMe or AncestryDNA) tell you what percentage of Neanderthal DNA you have, they do not always report on specific medical markers like the SCN9A variants (M932L, V991L, D1908G) in their standard health reports. You would typically need raw data analysis or specific medical genetic testing to confirm this.

Does this gene affect emotional pain? No. The SCN9A gene and the Nav1.7 sodium channel are strictly involved in the transmission of somatic (physical) pain signals from the peripheral nervous system to the brain. It does not influence emotional regulation or mental health conditions.

Are there people who feel no pain at all? Yes, but this is caused by a different type of mutation on the same gene. While the Neanderthal variant makes the channel more active, “loss-of-function” mutations in SCN9A can cause Congenital Insensitivity to Pain (CIP). People with CIP cannot feel physical pain, which is extremely dangerous as they often injure themselves without realizing it.

Did Neanderthals have other genetic impacts on us? Yes. Beyond pain sensitivity, Neanderthal DNA has been linked to various modern traits, including our immune system’s response to viruses, blood clotting rates, skin tone, and even hair texture.