Monetary origins pushed back
As I have previously explained, while these objects undoubtedly may have served some symbolic purposes, they were neither merely nor primarily symbolic. These necklaces were objects whose monetary properties, such as unforgeable costliness, divisibility, and security, were optimized given the available technologies (i.e. no metal working). These objects, which I have called "collectibles," differ from modern views of money only in two basic ways:
* They differ from many modern legal definitions of "money" (e.g. that of the U.S. Uniform Commercial Code) insofar as they were not minted or authorized by sovereign governments, hunter-gatherer societies having no such entities.
* Their primary uses were not for market exchange. Rather, by solving the double (or more) coincidence of wants problem, they solved more basic cooperation problems of kin altruism, reciprocal altruism, and the mitigation of aggression, and thus gained homo sapiens -- perhaps we should be called homo monetarius -- an important evolutionary advantage over homo neanderthalensis and other animals. This is probably also reflected in the human instinct to collect shells and other bright objects, an instinct not found in other primates and an instinct which would have allowed us to gain these advantages in cooperation over other animals.
Again my thanks to Ian Grigg for the pointer to this latest news.