Thinking strings: additional evidence for personal ornament use in the Middle Stone Age at Blombos Cave, South Africa.

Here we report on newly identified beads recovered from four Middle Stone Age levels at Blombos Cave and, in particular, on a cluster of 24 perforated Nassarius kraussianus shells that probably originate from a single beadwork. Contextual information, morphometric, technological and use-wear analysis of the 68 published beads and those recently found, coupled with experimental reproduction of wear patterns, allow us to reconstruct the most probable way in which the N. kraussianus shells were strung. The results reveal unexpected regularities but also variability through the various levels that we interpret as resulting from changes in beadwork manufacture and design over time. The Blombos Cave beads may document one of the first examples of changes in social norms affecting the production and design of symbolic material culture.