10 Stone Tools

101

Table 10.1 Criteria used by McGrew and Tutin (1978) and by Davidson and McGrew (2005) to decide whether chimpanzees or early hominin stone-knappers could be said to have met criteria for recognizing culture derived from Kroeber and Kluckhohn (1963)

Criterion	Chimpanzees	Stone industries	Questions for later archaeology
Innovation	Evidence slight, short	Yes – but then long stasis	What evidence is sufficient to recognize innovation among
	observation time		stone tools?
Dissemination	Circumstantial (but getting	Not certain – no studies	What precision of chronology would be needed, and what
	better)	of learning	type of pattern in the stone tools?
Standardization	Slight, but maybe	Probable but not certain –	Need to understand the constraints on knapping (see Kuhn
		problem of equifinality	in Nowell and Davidson 2010)
Durability	Quite good	Not certain – tools	Do similarities in stone artifact form arise from tradition or
		survive, but does	equifinality?
		tradition?
Diffusion	Not at the time of McGrew	Independent discovery	How do you account for the Movius line and the
	and Tutin (1978)	possible	“impoverishment” of early Australian tools?
Tradition	Yes	Probable, but	Was the Acheulean invented more than three times?
		archaeologists have only	(Africa, Europe and Australia)
		assumed it
Non-subsistence	Grooming hand clasp	Probably	Woodworking at Koobi Fora 1.8 Ma
Natural	Yes (but behaviors in	Uniquely hominin –	At what point does variation in stone artifact form stop
adaptiveness	laboratory and captivity are	experimental evidence	being a simple product of contingencies of manufacture,
	much more remarkable)	with apes irrelevant	on one hand, and use on the other?

through patterned interactions with adults (King 2002), or on the other those that want to retain the concept as a descriptor for the processes by which children come to have certain sorts of ideas and not others (Brown 2002). Unlike most of the traits used for identifying the “cultural” nature of ape or early hominin behavior, the emphasis here is on the socially-mediated inter-generational context of learning, which, again, is likely to be difficult for the study of archaeology and of apes in the wild. For reasons of this sort, emphasis shifted to socially-learned behaviors and their products and away from an emphasis on “knowledge, belief, art, morals, law, custom” and especially on the “best” among such traits.

Learned Behavior

How can such social learning aspects of a definition of culture be applied to non-humans? Such an approach might emphasize three requirements: consistency within groups, variation between groups and tradition over a number of generations. I should begin this discussion with a caveat about the word “social” which some purists might restrict to language-medi- ated interactions among humans. Clearly using such a definition would automatically exclude animals that do not use language from entry into the classification “social learning”, so in this context the word is taken to have a more general meaning which encompasses groups of animals consistently interacting with each other. Under this definition, social learning occurs where it is not individual learning alone, nor

learning by vertical transmission from parent to offspring alone, but includes observational learning which may be vertical, horizontal among peers in the “social” group so-defined, as well as oblique from adults to members of the next generation who are not their offspring (Box and Gibson 1999).

All learning tends to produce similarity between the behavior of the learner and the model – it is one of the ways in which we recognize that learning has happened. In this sense there is always likely to be consistency between behaviors that result from learning. But this is also true of behaviors that result from genetic determination, the functional requirements of dealing with specific environmental circumstances, or the equifinality involved in the limited means of producing certain types of artifacts (Davidson 2002; Moore 2011). The problem is not simple, as indicated by the example of Japanese macaques washing potatoes that is often cited as an example of social learning (Nishida 1986), but seems more likely to have resulted from individual discovery or learning (Visalberghi and Fragaszy 1990). The problem is how to tell whether there is social learning.

Teaching, the mirror image of learning, is commonplace among humans. Yet it is rare to find examples in which there seem to be elements of teaching among chimpanzees. The best documented case involves chimpanzee adults apparently scaffolding the actions of infants trying to crack nuts (Boesch 1991; Boesch and Boesch 1993; Boesch et al. 1994), but the length of time over which the process operates to achieve success is so long that it may be that chimpanzees learned by observational learning among the “social” group rather than as a result of the teaching. Such scaffolding actions may be no more than a rare behavior on which