Signs of Consciousness: Part III
The appearance of figurative and non-figurative marks associated with the human archaeological record of 40,000 - 50,000 years ago is the most dramatic of a number of signs of culture appearing at that time. An intriguing problem, perhaps one of the most significant for understanding human evolution, is why these signs of culture appeared when they did. Compounding this mystery is the fact that evidence for anatomically "modern" humans precedes this by at some 40,000 to 100,000 thousand years (e.g., Klein, 1989, 1995; Mellars, 1989; Stinger and Gamble, 1993). During this earlier period (roughly, the Late-Middle Paleolithic) anatomically modern humans provide no evidence of culture or technology fundamentally different from that of contemporary "archaic" humans. Moreover, evidence for the importance of culture for understanding human evolution is provided by the observation that modern humans were no more successful than their contemporaries in terms of expansion of home territory or population densities within those territories. Thus, modern humans appear to have existed some time without obvious technical and cultural development and they appear to have been no more successful than their contemporaries. That is, modern humans appeared to have no intrinsic advantage over competing species.
It is only as the array of recovered artifacts from the period from 40,000 to 10,000, that is, the Late Paleolithic, has grown has it become evident just how remarkable culture development was during that period. None of the claims listed are entirely uncontroversial, however, they do represent some of the best documented claims in the archaeology of the period. Only a few of the most significant events may be mentioned here. They include the first clear evidence of:
These cultural and technological developments were associated with other developments of enduring significance. These were:
All of these developments have been taken as significant hallmarks of unique modern human cultural and technological abilities. Yet they appear to not to have been achievements of modern humans for the first 40,000 to 100,000 years of their existence. This significant lag presents an intriguing mystery. One possibility is that apparently fully "modern" humans were not, in fact, fully modern anatomically after all. Perhaps there was some important, but subtle, biological evolution in those last 100,000 thousand years that brought humans over some neurophysiological threshold for the significant cultural innovations at about 40,000 before the present. Such changes may have entailed development in the fine structure of the brain, perhaps in the prefrontal cortex or its interconnections with other centers. Such changes would be virtually impossible to detect in fossil crania endocasts. The notion is eminently plausible but, at present, empirically quite intractable. Alternatively, perhaps the changes were in some aspects of social organization of culture itself that are not detectable in the fossil record. Indirect evidence, such as the gracile structure and relative lack of sexual dimorphism of "modern" humans compared to more robust structure and greater sexual dimorphism of "archaic" humans, may suggest a more enduring bond between mates and perhaps the potential for a family structure. Such physical distinctions had arisen earlier between different lines of hominids (e.g., among the Austalopithecines). Perhaps some greater conceptual powers associated with encephalization interacted with such social structures leading to more complex social organization, greater collective action, and some degree of specialization. The technological changes listed above may have required that culture structure, in addition to neurological structure, pass a certain threshold. This may have entailed some combination of cooperation and specialization among group members. Also, it is unlikely that one can overestimate the importance for, and cumulative impact on, all human culture, of the transmission of procedural and declarative knowledge between generations. A nuclear or extended family structure within a larger group provides an opportunity for the establishment of mentoring relationships across generations that "socialize" children into the patterns and technologies of the emerging culture. Perhaps only with the emergence of such relationships did human society have the requisite structure in place to nurture the technological developments of the Late Paleolithic.
A third factor, which would have interacted with the cultural factors, may have been significant developments in language. The linguistic abilities of "archaic" humans are among the most controversial issues in all of human evolution. The present argument does not require, however, the assumption that Neanderthals or other, even earlier, hominids were utterly bereft of language. Language is a collective enterprise. Language does not exist within the brain alone but equally within cultures. The issue is not really whether "archaic" humans were possessed of language but rather, what kind of language was it and what did they do with it (or perhaps better, what did it do with them)? All social animals communicate, of course, and primates do so in especially complex and productive ways (e.g., Cheney & Seyfarth, 1989). It seems likely that the hominid line continued and expanded upon this primate trend and that "archaic" humans must have employed at least some form of proto-language (Bickerton, 1991) to expand upon this primate tradition. Such a language could be used to communicate "in the field" with group members about both current events and short term plans. Yet, if they did not develop closely knit family groupings and mentoring relations across generations the long term effects of language were seriously constrained. It is not simply a matter of "communication", but of thinking collectively and productively. Human speech is thoroughly dialogical. It is not simply a matter of sending and receiving messages, but of mutually constructing a dialogue within which plans, concepts, and meanings are created, maintained and changed. In dialogue one is constantly challenged to clarify, make explicit, and defend one's utterances. Out of dialogue grows a more self-conscious and explicit forms of declarative understanding. On this view it was the co-evolution of language, family structure, and intergenerational dialogue (always a challenging enterprise) that critical to providing the infrastructure for the emergence of graphic representation. The neurological structures for, and the use of, speech may have existed before the Late Paleolithic but perhaps it was only in the Late Paleolithic that array of cultural conditions for the development of language, something that requires a history, or, at least, a tradition within which it may grow, interact with, and, finally, shape. The explicit creation of external signs such as those of parietal art provides clues that this development was well under way by the Late Paleolithic. Also essential, however, would have been the development of specific concrete technical skills to enable the actual discovery of external representation.
Lithic techniques developed substantially during the Late Paleolithic. Five significant developments were; 1) the increasing number, complexity, and flexibility of steps and actions requiring careful planning, preparation, and observation to create stone tools; 2) an increase in variety, number, and detail of specialized tools and, especially in the increase in the frequency of "microliths"; 3) the creation of complex tools that worked in combination; 4) the apparent increase in the development of secondary tools requiring detailed working using new techniques, and 5) learning the visual-motors skills to apply these techniques to the new materials with their sometimes subtle differences in their respective properties. These tools were made of antler, bone, ivory, stone, and, presumably, wood.
The first change suggests an increasingly hierarchical organization of work in addition to longer sequences of actions. The blade technology developed in the Late Paleolithic appears to have made the work more staged and hierarchical since a number of blades could be relatively easily separated from the core before further working on any one piece. Also different blades from the same core might be subsequently sorted and treated in very different ways. Both the initial preparation of the core as well as the subsequent decisions about the use of the resulting blades required careful observation of details of the materials as well as skillful hand-eye coordination to alter, develop, and transform those details in order to further work the materials (e.g., elaborate preparation of a striking platform). This close attention to detail is also evident in the greater variety of tools often identifiable by very particular features such as subtle differences in the angle or curvature of a cutting edge. The small size of many of these tools reveals highly developed fine-motor manual control on the part of the artificers of microliths of the Late Paleolithic. Another feature observed during the Late Paleolithic is the increase in the evidence for hafting of stone points and blades (i.e., providing them with handles), the provision of openings through which sinew or cords might be passed (e.g., needles and harpoons), and the spear thrower designed to be used in combination with the spear. In contrast to lithic tool construction that is essentially subtractive in nature these tools require additive and relational strategies in which components are brought together to make a functional and or structural unit. Finally, and most importantly for the present argument, would have been the production of a variety of secondary tools. These developments also reveal a further elaboration of the staging of the phases of tool construction inasmuch as some of the new lithic tools, such as the burin, may have been made expressly to work antler, bone, ivory, etc. This working of new secondary materials required a different sort of fine motor control. The working of stone required ever increasing precision of ballistic and static control in the use of hammerstones, in placement and control of punches, and in the application and directing of static forces in pressure flaking. In such activity there is a precise and predictable (and predicted) effect of human action. The use of stone tools to carve, scrape, cut, and etch softer stone and materials such as bone and antler requires both the further development of ballistic forces and application of static pressure as well as the smooth and dynamic application of translational force along a line or an arc. One technique for the cutting and removal of a needle from a piece of antler, for example, required the repeated tracing of two nearly parallel convergent curves. This may be among the earliest regular instances of nonincidental creation, not simply of an effect, but of a controlled repeatable trace of a human action. This trace emerged in the presence of intense focal attention to precise, protracted, and controlled eye-hand coordination.
In Pursuit of the Trace
The working of materials that can be cut by stone tools requires close attention to the traces of previous actions just as working in stone required close attention to the effects of previous actions. In both cases only a general idea or plan of the direction of work is required at the outset. The details of effective tool production require close and continuous attention to the effects and traces of each action of the artificer as the tool is gradually constructed by effective arrangement of effects. Indeed, the nature of stone and the element of unpredictability of fracturing characteristics likely precluded or, at least, worked against the utility of, the formation of a detailed plan of action or detailed guiding image for tool construction. Rather a rather vague intention combined with a degree of flexibility was required to accommodate to the details of the effects or each succeeding action as the tool and its conscious realization were simultaneously formed "on-line". Thus, in an analogous manner to perception itself, tool production begins in kind of prejudiced indeterminacy in which a positive identification is achieved through a coordination of interpretation and strategic action. Carving in such materials as wood, bone and antler, however, require more precise planning guided by a rather more definite notion of the final product. Here the artificer controls down to the finest detail the precise shape and even texture of the tool (such as modifying the surface of the base of a point for adhesion in hafting).
The most common traces left by cutting softer materials with stone tools such as the burin are lines of varying degrees of curvature and asymmetry of curvature. Perceptually, such lines may serve as surrogates for occluding bounds (Halverson, 1992; Hochberg, 1972; Kennedy & Silver, 1974). These traces constitute the most basic semiotic (or sub-semiotic, Elkins, 1995) elements. In the same manner as ambiguous figures and lines in nature encourage interpretation and a search for positive identification so must the traces (Davis, 1986). Some of these traces may have been incidentally diagnostic of objects of interest to the artificers. Accustomed as they had now become to shaping their activity to their emerging interpretations these artificers may have retraced, reinforced, and elaborated upon the traces as interpreted. This elaboration would further constrain interpretation, fairly rapidly converging on a configuration that could be positively identified as some particular object of interest. According to the RBC perceptual model this decision may occur after only two or three diagnostic components. Since the goal under this perception driven hypothesis is positive identification of the object there would be no tendency to recreate the object or achieve a high degree of completeness. Thus we may expect that the figures would, from the beginning appear to be "schematic" and incomplete, though highly recognizable as particular objects. On this view the production of graphic images arose in the context of secondary tool construction and was enabled by the nature of that tool construction. The coupling of perception, fine-motor skills, and on-line formulation and/or reformulation of planning is considered an essential development in the production of graphics. Indeed, even among highly graphically trained and literate humans detailed planning often requires considerable external support (measurements, notes, preliminary sketches, etc.).
The particular images that would be produced under the present model would have been a joint product of the perceptual prejudices of the artificers and the sorts of traces produced by the available tools in the materials being worked. Sometimes, because of the nature of the diagnostic features (the bison's hump, the horse's crupper) there was a close correspondence between the natural curve of the trace the prejudice would quickly drive the elaboration toward a positive identification of the animal. In other cases, there might be only the vaguest sense of structure guided by Gestalt features of closure, good continuation, etc., leading to the production of rectilinear figures and series of dots, lines, and other marks. Mastery of these graphics would have been engineered through continual alternation of exploration and play. Depending on the tools and materials used certain canonical forms, both of natural objects and of geometric and quasi-geometric forms could become established and repeated.