The offending display from the British Museum
A close-up of the offending display. Let your anger flow through you as you read the lies. Lies, I say! Okay, actually, there's some truth to it - we're not quite sure how money functioned prior to AD 1000, but it likely was a form similar to the bead system found in many other parts of the world.
I can only assume that whoever wrote the display copy had never bothered to actually read any books, magazine articles, or watch any television shows on prehistoric North America. If he had, he's have realized that shell bead money, much like that described for Africa and Australia, had been in use over much of North America. In fact, it's part of our American mythology that Rhode Island was purchased with beads that amounted to $20 (a rather huge embellishment based on a few semi-related true events).
In fact, the use of beads by many Native American groups was exploited by Spanish colonists in California during the 18th century.
Photo from bcartifacts.com
It's important to understand what money really is - we so often think of it as an object in and of itself, but it really isn't. It's essentially a way of storing wealth, much like a battery stores electricity*. In many societies, the creation of an early form of money acted as a sort of safety-net. During times of plenty, a person or group could trade away their surplus for the currency, in order to spend the currency during lean times in order to ensure that they had enough to survive. This allows the growth of complex exchange networks, and allows sedentary populations to form and grow in environments that are seasonally barren. If I can build up a stockpile of money when I am doing well during the summer when local foods are plentiful, then I can spend that money to buy food during the winter when local resources are more meager, but this ensures that I have to maintain good relations with someone who has plenty in the winter but is not doing so well during the summer. This leads to cooperation across ecological zones, and may be a step in the formation of more complex state-type societies.
Prior to the arrival of the Spanish, shell beads were used as the primary form of currency in California. Shell beads made from an Olivella biplicata shell were ideal for this purpose because they took effort to manufacture and were based on a relatively limited resource, limiting the quantity that were likely to enter the system at any one time. Ethnohistoric data from the Santa Barbara Channel region indicates that the value of a string of shell beads was dependent on the length of the string of beads, the quality of the beads themselves (both in terms of workmanship and in terms of how exotic the bead appears), and the difficult that it took to manufacture the beads.
The most valuable type of bead (to the point that it is considered "the money bead" by many anthropologists) is made from a part of the Olivella shell called the callus. This is a hard to get-at and hard to work thick piece of the shell (see the diagram below), and beads made from it were considered especially valuable and important.
Image from Benyhoff and Hughes Shell Bead and Ornament Exchange Networks Between California and the Great Basin
The Spanish used beads as gifts when meeting and trying to establish relations with the Native Californians. The hunger for the beads confused the Spanish, who thought that other goods that they had brought should be more desirable. However, as the native peoples had a rather complex economic system based on exchange of goods across ecological zones (coast to valleys to inland mountains, etc.) which used beads as the medium of exchange, and the Spanish beads would have been considered very high value in this system, the beads made for an ideal item to foster interaction.
Photo of European glass beads at the American Museum of Natural History
The beads also appear to have had a rather interesting effect, or at least I think that it had an interesting effect.
See, the types of shell beads made changed over time, and can be used to figure out how old sites are. the callus cup beads - the really valuable ones - were made during the Late Period (from approximately AD 1200 to AD 1770), a time when social, organizational, and economic complexity really took off. There is a fair amount of evidence that indicates that the callus cup beads became common during this period specifically because they were hard to make and therefore could be used as a medium of exchange (if not everyone is going to bother to take the time to make them then they are perceived as more valuable and therefore can serve as a way of storing and showing wealth). This is also a period during which populations grew, putting pressure on areas where food was only abundant during certain parts of the year, requiring that people of most regions create and maintain relations with other regions in order to ensure that they have a steady supply of foods and other materials.
The introduction of glass beads from Europe screwed the system. The glass beads, as noted, had a high value, and their introduction correlates with the disappearance of the callus cup beads. It appears that the glass beads were considered to be of such great value, that the callus cup beads couldn't keep up, and the bead makers were essentially driven out of business.
But if you look at a more common type of Olivella bead, called a wall bead (again, see the diagram above), there's something strange a'brewin'. These types of beads had been well made prior to the historic period. The material to make them was clearly carefully removed from the Olivella shell, the holes were drilled carefully, the beads were made to a regular shape (either circular or oval), and the edges were ground smooth.
Photo of Chumash-made shell beads, from NPS.gov
But after the glass beads are introduced, the wall bead shapes become irregular, the holes are not as carefully drilled, and the edges are either not ground as smooth and in many cases aren't ground at all.
What was going on here? Well, there's a number of explanations available, but I think that it may be that we are seeing inflation. The presence of the glass beads essentially destroyed the value of callus cup beads, resulting in them no longer being manufactured. I suspect, and keep in mind that this is my own interpretation and there are many other archaeologists who would disagree with me, that the wall beads also had a place within the economic system (either as money or as prestige goods or both - like the callus cup had been), and that the availability of higher-quality and more exotic glass beads resulted int he bead makers realizing that they couldn't compete in terms of quality, but they could compete in terms of quantity - and so lower-quality but easier-made beads became common.
Another explanation may be that the bead makers were specialists, and that the wall beads retained their importance into the Historic Period, but that the upset to the native economy due to the introduction of European goods meant that the bead makers had to find other ways of making a living, and therefore simply had less time to devote to bead making, hence the lower-quality goods.
Regardless of the explanation, it is interesting that, rather than simply eliminate a native industry, the introduction of European beads altered it.
Oh, and the people at the British Museum really need to do more homework when putting up displays dealing with the Americas.
*Much is made of the fact that much of the world's current money has no value behind it, and a minority of people demand that we MUST get back on a precious metal standard if we are to avoid calamity. Most money was once backed by gold or silver or other precious metals, but is now backed by nothing other than people all agreeing that it has value. However, this has always been the case for money - even gold and silver have little real use (outside of some relatively minor industrial uses) and are only of value because everyone agrees that they are.
In other words, contrary to what some people claim, if the economy collapsed tomorrow, having all of your finances tied up in gold and silver would do you no real good. Having all of your finances tied up in guns, bullets, and canned food, on the other hand, would put you in a position of power in the post-collapse world. Just sayin'.