Why Levallois? A Morphometric Comparison of Experimental ‘Preferential’ Levallois Flakes versus Debitage Flakes
Citation: Eren, M.I., and S.J. Lycett (2012) Why Levallois? A Morphometric Comparison of Experimental ‘Preferential’ Levallois Flakes versus Debitage Flakes. PLoS ONE 7(1): 29273 (RSS)
Internet Archive Scholar (search for fulltext): Why Levallois? A Morphometric Comparison of Experimental ‘Preferential’ Levallois Flakes versus Debitage Flakes
Tagged: Levallois (RSS), experimental (RSS)
Summary
Theoretical background
Levallois cores were frequently viewed as prepared cores, which was prepared in a deliberate and goal-orientated manner to make Levallois flakes. Some researches (Lieberman 1975) link such processes of tool making with the cognitive processes involved in language. However, other researches assume that there is no predetermination according to the less standardization of Levallois flakes (Dibble 1989). Whether the Levallois technology represents predetermination or not is still an issue. The author thinks that previous researches only measured few dimensional attributes and did not consider the multivariate statistic approach, which leads to limited results. Besides, the arbitrary classification will affect the results which based on comparative method. In order to better understand predetermination involved in tool making and the reason for the preference of Levallois flakes, he conducts an experiment to examine the attributes and standardization of preferential Levallois flakes by comparative study. The experimental assemblage was from the Cretaceous-aged Fredericksburg Group, and the author made the flakes according to the criteria by Boëda(1995) and Bradley(1977).
Methods and Materials
The experiment assemblage is from 25 nodules of Texas chert. A total of 642 flakes were examined in this study, including 75 preferential Levallois flakes and 567 debitage flakes produced during the manufacture. The flakes were divided into three groups, preferential Levallois flakes, ventral debitage flakes, and dorsal debitage flakes. There are 15 quantitative variables were measured for each flakes, including the dimensional attributes for different part of flake, bulb thickness, length of sharp edge, and index of symmetry. The analysis focused on two issues. First, if the preferential Levallois flake is a preferred product, they will have common attributes which unite them as a category. For this, the author conducted Discriminant Function Analysis to assign those samples to groups. Because the size of preferential Levallois flakes are usually bigger than debitage flakes, the author adjust the size by the geometric mean. Another argument is if the Levallois flakes meet special requirement, their attributes will present greater standardization than debitage flakes. The coefficients of variation and Mann-Whitney U-test were used to test different groups. The quantitative analysis was calculated by SPSS Statistics.
Results
The results show that preferential Levallois flakes can be viewed as a coherent group based on particular attributes, especially for the thickness. Moreover, the attributes of Levallois flakes are less variable and present more symmetrical than debitage flakes, which indicates more standardized in form. Based on the results, the author discussed the Levallois flake preference from the viewpoint of mobility. He suggested that the appearance of Levallois relates to increased mobility in hunter-gatherer population in Middle Paleolithic. The large surface area of Levallois flake provides not only the retouch potential, but also greater efficiency. Moreover, according to experiment, thickness is more evenly distributed and less variable across preferential Levallois flakes, which indicates the thickness is an important factor for retouch and reuse potential because of edge durability. The increased symmetry in flakes also increased efficiency in cutting performance. Based on the predetermination of Levallois flakes, the author supported the analogies between the hierarchical structure of tool making and the hierarchical organization of grammar in sentence.
Theoretical and Practical Relevance
The association of Levallois artifacts with extinct hominins leads to the debate about whether the extinct hominins such as Neanderthals possessed the cognitive and linguistic capacities. The concept of predetermination is a critical factor to support the “grammar” involved in both Levallois production (Holloway 1969). The author proved there is a predetermination for preferential Levallois flakes and suggested that the Middle Pleistocene hominins had similar way to make Levallois flakes and solve problem, which indicates the extinct hominins might process the linguistic capacities and there is no significant difference in cognitive capacities among these hominid species.
By conducting experiment and multivariate statistics, the author suggested the predetermination of preferential Levallois flakes and further discussed the preference for such flakes, which provides a foundation for the issue of linguistic capacity in early hominins. However, I think the connection between linguistic capacity and the predetermination of Levallois technology still needs more evidence.
