The online report has snapshots of the arrowheads.Kyle S. Brown of the University of Cape Town and his colleagues argue that the tiny points they found, which the ancient people at PP5-6 made by carefully heating and shaping stone, are a proxy for complex cognition and that the 11,000-year duration of the tradition indicates it was transmitted verbally from generation to generation.
http://www.nature.com/nature/journal/v4 ... 11660.html
