The paper entitled “Platforms of Palaeolithic knappers reveal complex linguistic abilities”  submitted by C. Gaucherel and C. Noûs represents an interesting reflection about the possibilities to detect the human cognitive abilities in relation to the lithic production.
The definition and the study of human cognitive abilities during the Lower Palaeolithic it has always been a complex field of investigation. The relation between the technical skills (lithic production) and the emergence of the linguistic abilities is not easy to investigate due to the difficulty of finding objective data to refer to. The proposition, made by C. Gaucherel and C. Noûs, of a formal grammar of knapping as a method to study the syntactical organisation of the reduction sequences, constitute a new and theoretical useful approach.
In order to effectively and precisely define the gestures linked to a specific reduction sequence, for example that of the handaxes shaping, a very large number of variables should be taken into consideration (morphology and quality of the raw material, experience of the knapper, context, percussion technique, forecast of use of the handaxe, etc.). But since a simplification, that brings more elements than the classic one [2,3] is needed, the “action grammar approach” can be a good instrument to detect the common element in a shaping reduction sequence. Furthermore, one of the advantages of the proposed methodology lies in the fact that the definition of the different STs (Stone Technology) can be done according to the technological specific characteristics to be studied and to the type of instrument produced.
The deconstruction of knapping sequences could help to detect the degree of complexity of the different steps of the reduction sequences also thanks to the identification of the sub-actions types. The increasing/decreasing of complexity is a very complicate concept in lithic technology. Since at the base of the lithic production there are two basic concepts (angle between the striking platform and the debitage surface - convexity of the debitage/façonnage surface) which are simply declined in an increasingly complex way, it is not easy to define uniquely in what exactly consists the increase in complexity. The approach proposed in the paper “Platforms of Palaeolithic knappers reveal complex linguistic abilities” can help to have new evidences, according to the identification of the required cognitive abilities.
The proposed example of formal grammar still needs to be confirmed on archaeological collections, but it is probable that a practical application will allow to further develop the methodology and possibly to highlight additional possibilities of the approach.
 Gaucherel, C. and Noûs C. (2020). Platforms of Palaeolithic knappers reveal complex linguistic abilities. Paleorxiv, wn5za, ver. 6 peer-reviewed and recommended by PCI Archaeology. doi: 10.31233/osf.io/wn5za
 Inizian, M. L., Reduron, M., Roche, H. and Tixier, J. (1995). Technologie de la pierre taillée. Préhistoire de la Pierre Taillée 4, Cercle de Recherches et d'Etudes Préhistoriques d'Antibes, Meudon.
 Tixier, J., Inizian, M. L. and Roche, H. (1980). Terminologie et technologie. Préhistoire de la pierre taillée 1, Cercle de Recherches et d'Etudes Préhistoriques d'Antibes, Meudon.