Hand Axes: what for?
Experiments by athletes expert at discus-throwing, organized by Eileen O'Brien, have suggested that the hand axe also had some interesting aerodynamic properties:
The hand axe demonstrated a propensity to land on edge when thrown overhand or discus-style, a tendency to land point first, and a potential for distant and accurate impact. Its overall shape minimizes the effects of resistance while in flight, as well as at impact. This is not true of an unshaped stone or a spheroid, for example. And despite its sharp edge, the hand axe could be launched without a safe handhold. The only apparent limitations to the hand axe's use as a projectile weapon are the strength, coordination, and skill of the thrower.
It may well be that the so-called hand axe was a specially sharpened stone missile - a specially made "throwing stone" just as the boomerang was a specially made "throwing stick". Eileen O'Brien was a research student at the time she came up with this brilliant idea. The idea was subsequently taken up by W H Calvin, but not seriously pursued, his speciality being neuroscience. No one else seems to have seriously pursued it and there has been some active opposition (see link).
No one has thought of a better use for the handaxe. If it was intended primarily as a hand-held cutting tool, it would have been perverse to make a sharp edge all round it. And if we assume as I do that pre-human bipeds fought their enemies by throwing stones and we also know (as we do) that they learned the ability to shape stones, it would be surprising if they had not improved on nature by making specialised stone missiles of some sort. No other surviving artifact answers this description as well as the handaxe. Of course they were so commonly available (many thousands have been found) that they may sometimes have served the purpose of a cutting tool as well.
A version of Eileen O'Brien's paper is at this link .