The development of human cognitive capabilities is one of the most interesting and complex topics in human evolution. Cognitive archaeology focuses on stone tools to give insight into it. Stone tools are linked to cognition because they are the product of a conscious goal-oriented action: stone knapping. In this sense, the aim of our research was to determine what technical gestures must be learned to produce stone tools. Knowing what the technical requirements of stone knapping are, we believe it is a first step towards understanding what its cognitive requirements are and, so, what the cognitive abilities of our ancestors were. To contribute to this first step, in this article we focused in the essential technical gestures of stone knapping.
Mean values (number of percussions) for the angle of percussion displayed by experts and novices - IPHES
Stone tools are the protagonist of cognitive archaeology, but they only retain information about the last stage of their production and use. To understand the cognitive aspects of stone tool production, we need to study the entire knapping process and, so we must turn to modern-day knappers. That is why we designed an experimental study to compare the performance of expert knappers and complete novices. We hypothesised that the differences between novices and experts would indicate which technical gestures experts had learned to successfully produce stone tools.
Nine experts and nine novices participated in our experiment. They were video recorded while attempting to produce a crude handaxe on a brick. The production of a handaxe was chosen because its reduction sequence is long and diverse enough to generate rich-knapping behaviours, while being easy enough for novices to achieve. Concerning the bricks, three reasons justified this choice: they have the same mechanical properties (conchoidal fracture) as stones; they provide a homogeneous raw material and a standardised core form for all subjects; and they are a safe material for complete novices to handle. Homogeneity of the raw material was important for the aim of the experiment because we wanted to determine the knapping variables regardless of raw material type. Through the use of bricks we neutralised the effects of raw material variability.
Mean values (number of percussions) for the position of the blank displayed by experts and novices - IPHES
Concerning the methodology of analysis, the video recordings were analysed with observational methods, which are used in Psychology and Ethology to study human and animal behaviour, respectively. In fact, the innovation of our study, apart from the results, is the application of the observational methods to archaeology. Observational methods allow segmenting any behaviour or action into units and, so, identifying which are the atomic elements of this action. In our research, the atomic elements are the technical gestures of stone knapping.
Looking at results, they showed considerable differences between experts and novices in three technical gestures: the type of percussion support, the position of the blank and the angle of percussion. Regarding the percussion support, experts used some part of their body, such as their tight, to support the blank while knapping, whereas novices put the blank on the ground or on an anvil. With regard to the position of the blank, experts tilted the blank while knapping it, whereas novices had it on a vertical position. Finally, experts knapped with an angle of percussion lower than 90º; on the contrary, novices knapped with an angle of percussion around 180º, that is to say, they hit the whole surface of the hammerstone against the blank.
Therefore, the technical gestures that have to be learned to successfully knap stone are the angle of percussion, the type of percussion support and the position of the blank. As explained by many experienced knappers, the angle of percussion must be acute (i.e., less than 90º), the blank must be supported on the body and finally, the blank must be more or less tilted. What is critical to learn is not each technical gesture individually, but the interaction between the three of them. Although on some occasions novices used an acute angle of percussion, the support on the body technique and the titled position, they did not manage to combine them.
In conclusion, these three technical gestures seem to be important variables in understanding stone knapping, both at the level of successful flaking and shaping. In this sense, if we reveal the challenges and difficulties a modern apprentice faces in acquiring, combining and mastering the three of them, we may begin to understand how stone knapping is acquired and what were the cognitive abilities of both the first stone knappers and the early bifacial stone toolmakers.
For further information
Article “What novice knappers have to learn to become expert stone toolmakers”. Geribàs, N.; Mosquera, M.; Vergès, J.M. Journal of Archaeological Science, 37: 2857-2870, November 2010