Handedness in the Krapina Neandertals : A Re-Evaluation

Dominant right-handedness is well-established in European Neandertals and their likely ancestors with ratios indistinguishable from modern humans. Based on a previous analysis of oblique scratches into the enamel, the Krapina Neandertals represent a large portion of the Neandertal sample with six right-handers and one lefthander. These scratches are produced when stone tools etch the tooth face in repeated oral manipulations. In this update, the Krapina sample was blindly re-analyzed by re-casting the teeth and re-cataloguing the scratches. Done by a different researcher (IF) from the original study (Lalueza and Frayer 1997), this was an independent test of the determination of handedness from scratch patterns in the Krapina sample. We confirmed the earlier results of a predominant right-handed pattern from the striations’ obliquity on the incisors and canines. Further, we identified the first deciduous tooth with a right-handed pattern, two more right-handers and added a second left-hander to the Krapina sample. Overall, our most up-to-date sample of all European Neandertals produces a frequency of about 90% right-handers. Handedness is a proxy for brain lateralization, and by extension, language capability. Coupled with other evidence from paleoanthropology to paleogenetics, it is apparent that Neandertals had all the capabilities of modern humans for language production. INTRODUCTION L scratches on a Neandertal incisor were initially documented by Martin (1923) at La Quina and subsequent researchers noted scratches on the labial faces of incisors and canines. The first systematic analysis of these scratches was done by Bermúdez de Castro et al. (1988), who documented a consistent right-handed pattern at Sima de los Huesos (Atapuerca) and provided the first experimental evidence to account for scratch patterning. Their categorization of the scratches into horizontal, vertical, left oblique, and right oblique intervals is now the established protocol for inventorying labial scratches. Frayer et al. (2010) provided a statistical procedure to more systematically predict when a set of labial scratches indicates the hand used to produce them. The advantage of using labial scratches for estimating handedness is that much larger samples can be generated in place of using skeletal or cerebral indicators. For example, because at Krapina there are no associated left and right bones of the arm chain, it is not possible to estimate handedness based on skeletal asymmetry. This is why scratches on the labial face of incisors and canines are so valuable. A disadvantage is that labial scratches are not common in the Upper Paleolithic or Mesolithic people following Neandertals in Europe or in more recent populations (Bax and Ungar 1999). This makes finding examples from subsequent European populations or ethnohistoric parallels difficult. Although a few cases of scratches in modern teeth have been documented (Lozano et al. 2009), no cases in modern groups show the degree of scratching found in Neandertals. We suspect that the often highly scratched labial faces in the anterior teeth of Neandertals and earlier Europeans are related to using flake tools. Once blade tools became the dominant method of the tool kit, the “stuff and process” habit became less prevalent. In 1997, Lalueza and Frayer documented labial scratchPaleoAnthropology 2015: 19−36. © 2015 PaleoAnthropology Society. All rights reserved. ISSN 1545-0031 doi:10.4207/PA.2015. ART93 IVANA FIORE Museo Nazionale Preistorico Etnografico “L. Pigorini,” Sezione di Bioarcheologia, P.le G. Marconi, 14, 00144 Rome, ITALY; iva_fiore@yahoo.it LUCA BONDIOLI Museo Nazionale Preistorico Etnografico “L. Pigorini,” Sezione di Bioarcheologia, P.le G. Marconi, 14, 00144 Rome, ITALY;