Trade and Large Populations are Needed to Sustain Innovation

The most striking case of technological regress is Tasmania. Isolated on an island at the end of the world, a population of less than 5,000 hunter-gatherers divided into nine tribes did not just stagnate, or fail to progress. They fell steadily and gradually back into a simpler toolkit and lifestyle, purely because they lacked the numbers to sustain their existing technology. Human beings reached Tasmania at least 35,000 years ago while it was still connected to Australia. It remained connected – on and off – until about 10,000 years ago, when the rising seas filled the Bass Strait. Thereafter the Tasmanians were isolated. By the time Europeans first encountered Tasmanian natives, they found them not only to lack many of the skills and tools of their mainland cousins, but to lack many technologies that their own ancestors had once possessed.

[...]

The archaeologist who first described the Tasmanian regress, Rhys Jones, called it a case of the ‘slow strangulation of the mind’, which perhaps understandably enraged some of his academic colleagues. There was nothing wrong with individual Tasmanian brains; there was something wrong with their collective brains. Isolation – self-sufficiency – caused the shrivelling of their technology.

[...]

Tasmania is about the size of the Irish Republic. By the time Abel Tasman pitched up in 1642 it held probably about 4,000 hunter-gatherers divided into nine tribes, and they lived mainly off seals, seabirds and wallabies, which they killed with wooden clubs and spears. That means that there were only a few hundred young adults on the entire island who were learning new skills at any one time. If, as seems to be the case everywhere, culture works by faithful imitation with a bias towards imitating prestigious individuals (in other words, copy the expert, not the parent or the person closest to hand), then all it would take for certain skills to be lost would be a handful of unlucky accidents in which the most prestigious individual had forgotten or mislearned a crucial step or even gone to his grave without teaching an apprentice. Suppose, for example, that an abundance of seabirds led one group to eschew fishing for a number of years until the last maker of fishing tackle had died. Or that the best barbed-spear maker on the island fell off a cliff one day leaving no apprentice. His barbs went on being used for some years, but once they had all broken, suddenly there was nobody who could make them. Acquiring a skill costs a lot of time and effort; nobody could afford to learn barb-making from scratch. People concentrated on learning the skills that they could watch first-hand.

Bit by bit, Tasmanian technology simplified. The most difficult tools and complex skills were lost first, because they were the hardest to master without a master to learn from. Tools are in effect a measure of the extent of the division of labour and, as Adam Smith argued, the division of labour is limited by the extent of the market. The Tasmanian market was too small to sustain many specialised skills. Imagine if 4,000 people from your home town were plonked on an island and left in total isolation for ten millennia. How many skills and tools do you think they could preserve? Wireless telephony? Double-entry book-keeping? Suppose one of the people in your town was an accountant. He could teach double-entry book-keeping to a youth, but would the youth or the youth’s youth pass it on – for ever?