U. KANSAS (US) — Research confirming that a Neandertal was right-handed could suggest a capacity for language, a new study shows.
There are precious few Neandertal skeletons available to science. One of the more complete was discovered in 1957 in France, roughly 900 yards away from the famous Lascaux Cave. Then, about two decades ago, researchers examined the arm bones of the skeleton—dubbed “Regourdou”— and theorized that he had been right-handed.
“This skeleton had a mandible and parts of the skeleton below the neck,” says David Frayer, professor of anthropology at the University of Kansas. “Twenty-plus years ago, some people studied the skeleton and argued that it was a right-handed individual based on the muscularity of the right arm versus the left arm.”
Scratch marks on the teeth from the Neandertal skeleton Regourdou. Enlarge. (Credit: University of Kansas)
Handedness, a uniquely human trait, signals brain lateralization, where each of the brain’s two hemispheres is specialized. The left brain controls the right side of the body and in a human plays a primary role for language.
So, if Neandertals were primarily right-handed, like modern humans, that fact could suggest a capacity for language, researchers say.
Now, a new investigation by Frayer and an international team led by Virginie Volpato of the Senckenberg Institute in Frankfurt, Germany, has confirmed Regourdou’s right-handedness by looking more closely at the robustness of the arms and shoulders, and comparing it with scratches on his teeth.
The findings are published today in the journal PLoS One.
“We’ve been studying scratch marks on Neandertal teeth, but in all cases they were isolated teeth, or teeth in mandibles not directly associated with skeletal material,” says Frayer.
“This is the first time we can check the pattern that’s seen in the teeth with the pattern that’s seen in the arms. We did more sophisticated analysis of the arms—the collarbone, the humerus, the radius and the ulna—because we have them on both sides.
“And we looked at cortical thickness and other biomechanical measurements. All of them confirmed that everything was more robust on the right side than the left.”
Neandertals used their mouths like a “third hand” and that produced more wear and tear on the front teeth than their back ones, Frayer says. “It’s long been known the Neandertals had been heavily processing things with their incisors and canines.”
The research on Regourdou’s teeth confirmed the individual’s right-handedness.
“We looked at the cut marks on the lower incisors and canines. The marks that are on the lip side of the incisor teeth are oblique, or angled in such a way that it indicates they were gripping with the left hand and cutting with the right, and every now and then they’d hit the teeth and leave these scratch marks that were there for the life of the individual.”
Research on Regourdou shows that 89 percent of European Neandertal fossils (16 of 18) showed clear preference for their right hands—very similar to the prevalence of right-handers in modern human populations. About 90 percent of people alive today are right-handed.
Such ratios suggest a Neandertal capacity for language, Frayer and his co-authors conclude in the study.
“The long-known connection between brain asymmetry, handedness, and language in living populations serves as a proxy for estimating brain lateralization in the fossil record and the likelihood of language capacity in fossils,” they write.
Source: University of Kansas