Symmetry is its own reward: on the character and significance of Acheulean handaxe symmetry in the Middle Pleistocene

Abstract

The full-text may be used and/or reproduced, and given to third parties in any format or medium, without prior permission or charge, for personal research or study, educational, or not-for-prot purposes provided that:• a full bibliographic reference is made to the original source • a link is made to the metadata record in DRO • the full-text is not changed in any way The full-text must not be sold in any format or medium without the formal permission of the copyright holders.Please consult the full DRO policy for further details. 2) Does handaxe symmetry increase through time, perhaps demonstrating evolving cognitive structures and social intelligence in archaic Homo?We present data addressing the first of these questions and offer a novel explanation for both symmetry and the apparent 'tyranny of the handaxe' in the Lower Palaeolithic world. Explaining handaxe symmetrySensitivity to symmetry is a fundamental element of mammalian visual perception, hardwired and controlled by an automatically functioning brain network residing in the medial occipital gyrus (Hodgson 2009). In humans, it forms part of a package of core geometrical concepts that emerges at the age of about four months. From an evolutionary perspective, this may reflect that biologically important objects (such as people, predators and prey) are symmetrical, making symmetry perception a key discriminatory tool for processing visual information and, thus, vital for survival (Wynn 2002;Hodgson 2009).Yet, while symmetry may be evident in the pattern recognition mechanisms of animals in general (and ubiquitous in the natural world), it was only with the emergence of hominins of the Homo erectus grade and the Acheulean techno-complex (~1.75ma) that humans began to artificially impose symmetry (and shape) onto stone tools, in the form of handaxes. It is the imposition of form onto the world, rather than simply perceiving it in the world; that act constitutes for Wynn (1995, 2002) a cognitive leap, especially in shape recognition (symmetry, mirroring) and spatial thinking (the knapping process). The putative increased levels of symmetry after 500ka, when it is found not only in plan-view but also more commonly in side-and end-views, marks another cognitive milestone that saw the development of modern Euclidian understandings and manipulations of shape and space (Wynn 2002: 402). By this point, hominins were also able to intentionally manipulate symmetry in other ways, sometimes deliberately violating it by creating twisted edges-as Materials and methodsTwenty-two British Lower Palaeolithic assemblages were analysed, ranging in age from MIS13 to MIS8 (~520-300ka) and comprising 1405 handaxes. These were selected because they represent stratigraphically secure groups recovered from excavations, or by unbiased collectors (Roe 1968; White 1998a). The assemblages are listed in Hardaker and Dunn (2005) divided handaxes into six handaxe symmetry classes (HSC) and provided a description for each class (Table 2); a graphical key to understanding these values is p...

Were Acheulean Bifaces Deliberately Made Symmetrical? Archaeological and Experimental Evidence

“…The two most symmetrical assemblages in this sample were Boxgrove and Isinya (Fig. 6), with other studies also finding that Boxgrove is a particularly symmetrical assemblage for the British Acheulean (McNabb et al 2018;White & Foulds 2018), and Isinya is a particularly symmetrical assemblage for the East African Acheulean (Shipton 2018). Boxgrove is generally regarded as one of the finest examples of Acheulean biface manufacture (Stout et al 2014), having some of the thinnest bifaces in the Acheulean world (Shipton 2013); while comparison of Isinya with other biface assemblages from East Africa shows that its bifaces are also particularly thin and have particularly straight edges (Shipton 2018).…”

“…Olorgesailie CL1-1 is the oldest assemblage in the sample at over a million years old (Owen et al 2008), and has the lowest SDI score (Table 1). In very lightly reduced blanks, there may be an effect of more flake removals increasing symmetry (see also White & Foulds 2018). For most Acheulean assemblages, however, symmetry is a property independent of reduction intensity.…”

“…One of the most hotly debated issues surrounding Acheulean bifaces is the reason for their typically symmetrical shapes. Symmetry is a common, though not universal (McNabb & Cole 2015; White & Foulds 2018), feature of Acheulean bifaces that sets them apart from many other stone artefact categories. A butchery experiment, in which the influence of both plan and profile handaxe symmetry was measured, found only plan symmetry had an effect on efficiency and that this effect was weak (Machin et al 2007).…”

“…A butchery experiment, in which the influence of both plan and profile handaxe symmetry was measured, found only plan symmetry had an effect on efficiency and that this effect was weak (Machin et al 2007). This apparent overdetermination in handaxe symmetry has led to suggestions that hominins derived intrinsic pleasure from the aesthetic quality of symmetry (White & Foulds 2018): an incipient artistic appreciation (Le Tensorer 2006) based on ancient symmetry detecting neural pathways (Wynn & Gowlett 2018). Another popular interpretation is that symmetry was a display marker for trustworthiness as a co-operative partner (Spikins 2012), or suitability as a mate (Kohn & Mithen 1999; Mithen 2003).…”

Semiotics and the Origin of Language in the Lower Palaeolithic

“…Culturally transmitted conventions of tool-making and tool-use change in the Acheulean as seen in the shift in Southwest Asia by 500 ka away from the large flake tradition with its giant cores, use of coarse raw materials, and abundant cleavers towards smaller cores and finer-grained materials for making hand-axes and the discontinuation of cleavers as a tool form (Sharon 2008;Malinsky-Buller 2016). In Western Europe, subtle regional variations emerge in biface conventions among contemporary groups between 500 and 400 ka (White 1998;Ashton 2016;White and Foulds 2018;García-Medrano et al 2019). In Britain, a distinctive range of hand-axe forms exists with some forms difficult to make and these two features are interpreted as evidence of socially transmitted norms (Shipton and White 2020).…”