new study of skulls from Neolithic Scandinavia shows that 1 in 6 adults had suffered serious head trauma that was likely caused by a weapon. The anthropologists studied 478 skulls from Denmark and Sweden dating to between 3900 B.C. and 1700 B.C. Men had more non-lethal wounds, but women were just as likely to have died from blows to the head as men. The study was led by Linda Fibiger, an archaeologist at the University of Edinburgh in Scotland.
an extensive section on Neolithic Axes, should you wish to see even more.