Guillermo Zorrilla-Revilla, from Centro Nacional de Investigación sobre la Evolución Humana (CENIEH), has led an experimental study just published in the journal Lithic Technology which shows how the knapper's experience influences the lithic industry dispersion at archaeological sites, by analyzing the relationships between human factors and the spatial distribution of handaxe flakes.

Prehistoric instruments undergo post-depositional processes once the human being has produced and abandoned them. These processes hinder the analysis of prehistoric knives and the knappers who produced them (their body posture or level of experience).

This study looked at whether researchers could discern in situ assemblages (unaltered or slightly altered ones) through recognizing individual human factors at play in site formation.

“It was already known that posture while knapping, handedness, and the choice of working surface affect the dispersion of lithic remains. However, we find nothing regarding experience", says the Universidad Internacional Isabel I de Castilla researcher Marcos Terradillos-Bernal, co-author of this study.

Experimental archaeology was called on to fill this gap, and three knappers reproduced an assemblage of 18 handaxes, with the objective of seeing how the knapper's position and experience affect the shape, size and spatial distribution of the fragments that fall to the ground (flakes).

“The expertise built up over years of knapping practice provides skills that are embodied in the gestures used and control over the force exerted when extracting flakes. We now know that these skills affect the dispersion of flakes in space, and therefore how an archaeological site should be interpreted”, states Zorrilla-Revilla.