Dentition from a Neanderthal skeleton has provided clear signs of right-handedness, a trait unique to humans, which also indicates a capacity for language.

A dominant right arm has been theorised for decades since the discovery of the famous 'Regourdou 1' skeleton and the comparison of muscularity in its left and right arm,1 and a recent study of Regourdou 1's mandible has proffered further tangible proof of this. A complete set of fully erupted, permanent teeth have been preserved, showing differential signs of tooth wear. Volpato et al.2 have identified scratches on the right mandibular incisors, which typically indicate right-handed manipulations carried out at the front of the mouth, such as the 'stuff and cut' scenario, where meat was held in the mouth and portions cut very close to the lips. This scratching on the right labial surfaces of the incisors and canines suggests the mouth was used as a 'third hand'.

These findings have great implications for human evolution, as right-handedness signals brain lateralisation – specialisation of the brain's two hemispheres. The left side of the brain controls the right side of the body as well as playing the largest role in language. Evidence of a dominant right hand therefore suggests Neanderthals had the ability to form language.