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Flake selection and scraper retouch probability: an alternative model for explaining Middle Paleolithic assemblage retouch variability

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Abstract

It has been proposed that the relative abundance of retouched objects in Paleolithic assemblages can serve as a measure for artifact transport and by extension a proxy for site occupation duration. This approach is based on the assumption that retouch represents curatory effort for extending the service time of transported artifacts when raw material access is uncertain or limited, a condition that could arise when groups move frequently over long distances across the landscape. This paper proposes an alternative model that explains retouch as a probabilistic outcome of an expedient, on-site flake selection process. A simulation illustrates that the model is capable of producing assemblage retouch configurations akin to those commonly observed in Paleolithic settings. The simulation also indicates that the threshold applied by past individuals for selecting particular artifacts is an important parameter for explaining assemblage retouch variability. Using artifact weight as a proxy for flake selection criteria, several Middle Paleolithic assemblages exhibit patterns that support predictions made from the model simulation. Findings suggest that variation in scraper frequency among the studied assemblages can be accounted for by an interaction between the abundance of artifact production events and shifting artifact selection criteria, without appealing to higher-level behaviors of technological and mobility strategies.

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Acknowledgements

Many ideas presented here were developed through discussions with Harold Dibble, Dennis Sandgathe, and Alex Mackay. Thanks to Harold Dibble and Shannon McPherron for the permission to use the Roc de Marsal and Pech de l’Azé IV data. R functions for R 2-like effect size, dispersion parameter, and GLMM stability are courtesy of Roger Mundry. Harold Dibble, Shannon McPherron, Matthew Douglass, and Alex Mackay offered valuable comments on early drafts. Comments from two anonymous reviewers helped improve significantly the quality and clarity of the paper.

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  1. Centre for Archaeological Science, School of Earth and Environmental Sciences, University of Wollongong, Wollongong, NSW, 2500, Australia

    Sam C. Lin

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Fig. 7
figure 7

Simulation outcomes with increased and decreased retouch probability at model stage III-b. Total artifact count and the proportion of retouched artifacts in the simulated assemblages with utility selection thresholds of 15, 30, and 45

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Table 3 The original model coefficients and their respective minimum and maximum coefficients produced by a case-wise deletion of random effect levels
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Lin, S.C. Flake selection and scraper retouch probability: an alternative model for explaining Middle Paleolithic assemblage retouch variability. Archaeol Anthropol Sci 10, 1791–1806 (2018). https://doi.org/10.1007/s12520-017-0496-3

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