Special Issue: Innovation and the Evolution of Human Behavior

The manufacture of all complex artifacts depends upon the maker’s ability to control individual variables and their interactions. All such artifacts are multivariate in nature, and often they can be made at different sizes—in consequence it is vital for the maker to possess a sense of the proportions involved, in order to make the necessary transformation. This ability is keenly developed in modern humans, and also is apparent in Acheulean bifaces. There it has been noted particularly in highly controlled Breadth/Length relationships, although it also features in other dimensions. Several authors have commented on the recurrence of the proportion 0.61/1 (Golden Section) in the bifaces. Its presence is evaluated here in the context of various biface assemblages from Africa and Europe. Many of them have mean B/L values of 0.61. But some of them are quite clearly not made to Golden Section (e.g,. the Spanish assemblage of San Isidro, where the mean is 0.53). A case is set forward here that the ratio of 0.50 (1:2) is preferred for long bifaces. Thus any innate preference for the 0.61 ratio, or any other, appears to be a relatively weak one that can be overridden. Early artifacts demonstrate remarkable early human abilities to control dimensions, and also to impose allometric adjustments, but despite the frequent recurrence of the Golden Section value, it is far from universal. The results imply that the very acute modern human sense of proportion has a history in earlier Homo going back more than one million years. It seems likely that ranges of preference for particular proportions existed in earlier Homo, somewhat comparable to those observable in modern humans. The “Innovation and Evolution” workshop was held at the Centre for the Archaeology of Human Origins, University of Southampton, United Kingdom; workshop papers guest edited by Hannah Fluck (University of Southhampton; and, Landscape, Planning and Heritage, Hampshire County Council), Katharine MacDonald (Faculty of Archaeology, University of Leiden), and Natalie Uomini (School of Archaeology, Classics and Egyptology, University of Liverpool). This is article #7 of 7. W should the sense of proportion be important? The argument starts roughly like this. Animals need to perceive the world in which they live, so that they can behave. Often behaving is just moving, but the act of gaining food can be a complex set of operations, involving external manipulations, such as twisting or breaking plant or animal parts. Then a higher order of manipulation altogether is to make things, imposing oneself on the external world through construction. The things can be made only through the appropriate actions, however prescribed. These are the projection of instructions from the brain into activity in the external world. In that three-dimensional world all but the very simplest artifacts are multivariable or multivariate constructions. They have to be made ‘out there’ at some particular size, and that is achieved only if the contributing variables are all scaled appropriately —in proportion. This paper aims to examine evidence for that sense of proportion in the early archaeological record, and to see how definitely it is imposed. The ability to make external constructions can be seen as a very significant threshold in the evolution of brains and minds. Some of the manufactures are made by birds and insects, but the regular construction of complex objects ‘out there’ is limited to humans. As humans we find such action sequences sufficiently easy in concept that often we do not analyze their requirements (but see, for example, Hoc 1988). Take the analogy of building a space station. You cannot just build it. All the components have to be shipped up in a particular way, so that the installation can be put together. In a way the same is true for all artifacts. A set of instructions in the head (perhaps you can imagine all the requirements for a fine hand-axe) cannot simply be floated out into the external world as the object. The ideas have to be broken down, deconstructed, for successful assembly ‘out there’. The sense of proportion is one of the basic requirements, fundamental to the analysis of visual information in PaleoAnthropology 2011: 174−187. © 2011 PaleoAnthropology Society. All rights reserved. ISSN 1545-0031 doi:10.4207/PA.2011. ART51 JOHN A.J . GOWLETT British Academy Centenary Project, SACE, University of Liverpool, L69 3GS Liverpool, UNITED KINGDOM; Gowlett@liv.ac. uk Special Issue: Innovation and Evolution. The Vital Sense of Proportion• 175 spectives (e.g., Arnheim 1955; Benjafield 1976; Benjafield and Davis 1978; Boselie 1984; Fensom 1981; Fischler 1981; Godkewitsch 1974; McManus 1980; Plug 1980; Stone and Collins 1965). This ratio was strikingly evident in the mean of Breadth/Length in the hand-axes from Kilombe (Gowlett 1982; Figures 1 and 2). It appears also in the bifaces from Nadaouiyeh in Syria (Le Tensorer 2006), and subsequently, notably, features as the mean of the series of more than 400 bifaces from Boxgrove (Pope et al. 2006). Quite independently all these authors have been struck by the finding, but also somewhat puzzled by it. Le Tensorer (2006), for example, notes that later bifaces from Nadaouiyeh are less refined, and do not respect the ratio. Pope et al. (2006) go on to demonstrate the presence of Golden Section in many other biface series, and highlight the semiotic potential of hand-axes, noting the effect that their pattern of discard might have in marking out significance in a landscape. Here they echo White (1962) who talked of artifacts ‘symboling’ through passing on their ‘bestowed’ meaning. The importance of the bifaces in development of an aesthetic sense has been noted various times (e.g., Schmidt 1936; Oakley 1981; Gowlett 1982; Mithen 2003; Pope et al. 2006; Le Tensorer 2006), and recent work in neurosciences gives hope that some of the specific mechanisms of such a sense can be elucidated (Cela-Conde et al. 2004). From all this work it is tempting to say that there is something aesthetically special about the presence of the ratio, and that this was in the minds of the Acheulean toolmakers. Early on I became unconvinced by this explanation for at least three reasons, all empirical. The first came from studying two further assemblages, from Kariandusi, at about the same time (Figure 3). These belong to the same time range as Kilombe, and are only 80km away (Gowlett 1980; Crompton and Gowlett 1994). The raw materials contrast strongly—beautiful obsidian bifaces make up nearly the whole set from the Upper Site, originally studied by Louis Leakey. Those from the Lower Site, on the opposite side of the Kariandusi River gorge, are all made from a local trachyte lava. They may be slightly younger, but both sets are dated to ca. 1.0 Ma (Evernden and Curtis 1965; Gowlett 1980; Deino et al. 2004; Trauth et al. 2005). The ratios can be compared with Kilombe as follows: Length Breadth/ Length Thickness/ Breadth Kilombe (all) (N=394–400) 149 ±31 0.61 ±0.07 0.47 ±0.11