The Imposition of Symmetry in Handaxes

The idea that the imposition of symmetry is not something that confers a function advantage has been used to explain why hand axes were made symmetrical. The sexy hand-ax theory is that you make symmetrical hand-axes to demonstrate your skill and by demonstrating your skill, you are then able to attract a mate. Other ideas are that they are social, that napping styles are learned socially groups develop a particular way to nap a hand-ax and they pass on knowledge of how to do that to the next generation. Can you trace cultural contact through hand-ax shape between different groups?