Did Neanderthals Have Language? New Research Suggests They Had the Genetic Hardware for It, Like Humans

Specific genomic regions that seem to play a role in human language development evolved hundreds of thousands of years ago, before humans and Neanderthals diverged from a common ancestor, a new study finds

As they roamed around Europe and Asia between 400,000 and 40,000 years ago, Neanderthals had some hallmarks of humanity, including culture and organized social structures. But did they have language?

That remains an open question—one that scientists may never be able to answer fully, unless they figure out a way to travel back in time. But new research, published in the journal Science Advances, suggests that these prehistoric human relatives at least had the genetic hardware for language.

Coupled with what researchers have gleaned about Neanderthals’ cognitive capabilities, the results “heavily” imply that “some form of complex communication was part of the picture,” study co-author Jacob Michaelson, a psychiatrist and neuroscientist at the University of Iowa, tells IFLScience’s Benjamin Taub.

“Our findings, along with what’s been coming out of archaeology and ancient genomics more broadly, make the old ‘Did Neanderthals even speak?’ question very hard to sustain,” he adds.

Michaelson and his colleagues discovered that specific regions of the human genome seem to play a key role in our language abilities. Additionally, their work suggests that these regions evolved hundreds of thousands of years ago, before humans and Neanderthals diverged from a shared ancestor.

These genomic regions are known as “human ancestor quickly evolved regions,” or HAQERs for short. HAQERs are not genes but, rather, regulatory sequences that affect how and when genes are expressed. They’re relatively small, making up less than a tenth of a percent of our DNA. But, according to the researchers, they seem to have an outsized effect on human language development.

“There’s no single gene for language,” Michaelson tells Scientific American’s Jackie Flynn Mogensen. “It’s the collective effect of variation across all these different sites that seems to be the major explainer of individual differences in language.”

To reach this conclusion, scientists studied the genomes of 350 children who repeatedly took more than a dozen language ability tests as they progressed from kindergarten through fourth grade. HAQERs had roughly 200 times more influence on language ability than other regions of the genome, the researchers found. When the scientists broadened their focus to include more than 100,000 individuals enrolled in other studies around the world, a similar pattern emerged.

HAQERs appear to have evolved after hominins and chimpanzees diverged from a common ancestor species that lived between six to eight million years ago, the scientists discovered. But they arose before Homo sapiens and Neanderthals split from a common ancestor—possibly Homo heidelbergensis or Homo antecessor—that lived between 765,000 and 550,000 years ago.

This timeline suggests that the genetic roots of humans’ complex language may run even deeper than previously thought.

“Through eons of evolution, our species has been optimized for this,” Michaelson tells Scientific American.

The researchers discovered that Neanderthals also had HAQERs, and that they may have been even more prominent than those found in humans today. This doesn’t necessarily mean Neanderthals had language, but it suggests they had the genetic mechanisms in place in order for it to develop.

However, some experts take a more skeptical view of the role HAQERs might have played in Neanderthals and early humans. Though today the genetic sequences appear to be associated with language ability, they may have initially developed for some other reason.

“We cannot know with certainty if these sequences arose in our ancient past because they granted language abilities in our ancestors,” says Mark Pagel, an evolutionary biologist at the University of Reading who was not involved with the research, to Scientific American. “They evolved during a time of rapid expansion of the hominin brain, and so their origin might lie in promoting that evolutionary brain growth.”

HAQERs have remained relatively constant for the last 20,000 years, the researchers discovered. That was a bit of a surprise, because traits that are advantageous to survival tend to continue to evolve and accumulate.

The scientists think they may know why. They suspect that HAQERs promote brain development in such a way that also causes the brain—and, thus, the skull—to grow in size. But, until recently, babies’ heads could only get so large before they would increase the risk of death for both mother and child. That anatomical limitation likely restricted HAQERs from evolving any further.

“We think that early humans maxed out this pathway to developing the kind of brain that could be a vessel for language and they hit that ceiling pretty early on and then remained stable, while other aspects of genetics that improve brain development for higher intelligence, but don’t directly affect fetal brain size, continued to evolve,” Michaelson says in a statement.