Flake-Making and the "Cognitive Rubicon": Insights from Stone-Knapping Experiments

Stone tools have a continuous record extending some 3.3 million years. Our hominin ancestors engaged in relatively simple stone flaking, and stone tools of extreme complexity were produced by cognitively modern humans in the Pleistocene and Holocene. For this reason, stone tools offer a tangible means for tracking the evolution of cognition in our genus. This chapter discusses a recent series of experiments controlled for modern flintknapper intent, the results suggesting that aspects of ancient tool forms sometimes viewed as deliberate can in fact be produced with no more intention than that seen in the removal of individual flakes. But the removal of individual flakes is itself a cognitively challenging task, one that places the earliest hominin flintknappers across the "cognitive Rubicon" from their primate relatives.