Bifacial handaxes play a prominent role in the history of archaeology, and science more generally.  John Frere was the first to recognise the significance of stone handaxes when he found examples of them in ancient sea deposits at Hoxne in Suffolk, alongside bones of extinct animals.  He suggested in his 1797 paper that they came from ‘a very remote period indeed; even beyond that of the present world.’  Workmen discovered many handaxes at Hoxne, and ‘emptied baskets full of them into the ruts of the adjoining road’.

But the scientific establishment was not ready for such heresy, so the paper was ignored for another 40 years until similar handaxe finds were published by Boucher de Perthes in France.  These French artefacts (and, later, the Hoxne handaxes) were subsequently accepted as ancient tools when the leading geologist of the time, Joseph Prestwich, along with a founder of stone tool studies, John Evans, visited France in 1858 and became convinced by the stratigraphic evidence.  The acceptance of great antiquity for humans was an important backdrop for Charles Darwin’s book on evolution by natural selection.

Handaxes have since become one of the most iconic stone tools from human evolution and the most-studied tool type from the Lower Palaeolithic.  Handaxes are common in the archaeological record of Africa, Europe, West Asia, and India, but are rare or absent from East and Southeast Asia and Indonesia.  Most archaeologists would agree that the Acheulean saw a development in handaxe morphology, from relatively crude early versions at about 1.76 million years ago, to highly symmetrical tools by about 500,000 years ago.  A ‘classic’ later Acheulean handaxe demonstrates bilateral symmetry (symmetry around the length axis), with a thick proximal end (‘butt’) and a thin, tapered distal end (‘tip’).  The earliest handaxes were made by percussion flaking using a hammerstone, and later handaxes may have been finished using a soft hammer, such as a bone.  Handaxes continued to be made into the Middle Palaeolithic in some regions, including by Homo neanderthalensis in Europe.

Handaxes are intriguing because they are found in vast numbers on some sites, far more than you might expect for a simple cutting or chopping tool.  Also, handaxes dominated stone technology for some 1.66 million years.  Both of these patterns demand explanation, and the archaeological literature is rife with debate.  The dominant view is that these patterns reflect the slowly-evolving cognition and tool-mediated social behaviour in our hominin ancestors.  The data that drives these debates is mostly from studies of handaxe shape, augmented by detailed statistical analysis of attribute measurements, a field of study called morphometrics.

In a contrasting view, the archaeologist Iain Davidson argued that archaeologists cannot reliably determine whether an artefact was a deliberate product or simply an accidental byproduct of making something else.  He coined the phrase ‘the finished artefact fallacy’ to refer to the common assumption that archaeologists’ typological categories reflect design intentions of ancient hominins.  It is possible that handaxes were the discarded cores from making flakes for tools, and the various symmetries and attributes identified on handaxes may be due to restrictions of the mechanics behind stone-flaking, rather than deliberately-produced features.  Further, identifying a class of tools as a ‘handaxe’ based on shape and symmetry tended to ignore the fact that these objects are a subset of continuous variation.  For instance, some handaxes are elongated versions of bifacial cobble cores like those seen in the Oldowan, and there are a large number of bifacial tools in all Oldowan and Acheulean assemblages that are not elongated (and therefore not classified as ‘handaxes’, so not included in morphometric analyses).  In this case, analysts are studying archaeologists’ conventions regarding symmetry and what they choose to analyse, and not hominin design intentions.