Consider the third dimension: A new approach for measuring the symmetry of the middle Paleolithic points of the Mirak Site

There is evidence that recognizes the importance of symmetry in the study of the evolution of hominid cognition. The development of stone tools parallels the evolution of human cognition. The last three decades have used quantitative methods that the most important of which is Symmetry Index. This paper proposes a new methodology for measuring the deviation of symmetry using 3D comparison. It focuses on the stone points of the largest Middle Paleolithic open-site in Iran, Mirak. Our results show that the index of deviation of symmetry (IDS) assesses all of the points as symmetrical tools, while this number drops to 133 pieces using 3D comparison. In addition, paired samples t-test suggests a positive correlation between the increasing proportion of preparation removals and the decrease in deviation of symmetry on the two sides of the tools. Thus, it is likely that symmetry is affected by the morphology characteristics.