Abstract
Use of archaeological evidence in discussions of the origin and evolution of grammar has proved unconvincing largely because of undeveloped theoretical assumptions about the cognitive connection between language and tool behaviour. This paper examines the cognitive basis of tool use and tool making and concludes that there is no sound theoretical basis for inferring grammatical abilities from prehistoric stone tools. Our knowledge concerning the cognitive basis of tool behaviour can, however, be used to document evolutionary developments in hominid cognition. Analysis of early biface culture, for example, reveals a cognitive complexity greater than that demonstrable for the earlier Oldowan or for modern apes.