Hafted spears and the archaeology of mind

By as early as 200,000 years ago hunters in Africa, the Middle East, and Europe had begun hafting stone points onto the ends of their spears (1⇓–3). This marked a significant step in the history of technology, for it was the first time that hominins had united separate elements into a single tool. Indeed, these compound tools actually consisted of three distinct elements: the point, the shaft, and the haft itself. It was the haft that was the challenge because it had to withstand significant impact forces when the spear was used. Many archaeologists consider the development of hafting to mark a major watershed not just for technology, but for the human mind itself (4). But just what is required, in a cognitive sense, to be able to haft a point to a shaft? In this issue of PNAS, Wadley et al. (5) set out to answer this question by duplicating one such hafting technology, identifying the procedures and knowledge required, and arguing that abstract reasoning was an essential prerequisite. In doing so they provide a good example of a relatively new perspective in paleoanthropology—that of cognitive archaeology.