As I write this, two artifacts of roughly the same size and shape sit on my desk: a cordless mouse and a hand axe from the Middle Stone Age. Both are designed to fit the human grip. Both are technologies. Yet the difference between them is profound.
The hand axe represents a technology that did not change for a million years; it evolved slower than the human skeleton. The mouse will be obsolete in a few years. The axe consists of a single, natural substance. The mouse is a complex confection of metals, semiconductors, plastics, and lasers. The axe was made by a single individual. The mouse was made by thousands—perhaps millions—of people, each of whom played a small role in realizing the whole. Farmers grew the coffee that shippers transported and was consumed by oil riggers whose petroleum was used by refinery workers to make the plastic that was molded by factory workers for the mouse, which was assembled by other laborers for salespeople to sell to the retailer who sold it to me. Not one of them alone knows how to make a computer peripheral from scratch.
And yet, it is the mouse, not the hand axe, that is the key to understanding why human beings dominate the planet and why there has been such explosive prosperity and progress over the past 100,000 years. The knowledge of how to make the mouse—and so many other modern-day products—transcends the limitations of the human brain. Our ability to plan and to think and to communicate ideas through language may be impressive, but it still requires each of us to understand every idea that settles within our own skulls. When we moved away from self-sufficiency and began to work together, combining our knowledge, the consequence was far-reaching: We created things we could not and do not understand, from cordless mice to urban metropolises.
Cooperation turned us into specialists: I’ll do this job, you do that one. Specialization gave us incentives to innovate. Innovation led to yet more specialization and more ways of combining different specialized skills. Human intelligence became collective and cumulative to an extent that no other species can rival.
The key human invention, therefore, was exchange—the ability to trade ideas and efforts. We do this every time we go to the office. We produce one specialized thing or service, and in exchange we get to tap the resources of hundreds of other people, from janitors to actors, from coffee growers to electrical engineers. The more specialized our work becomes, the more diversified our consumption.
Exchange had precisely the same effect on our culture that sexual reproduction had on evolution through natural selection. In asexual species, wholly different mutations that arise in different lineages cannot be combined. They compete with one another, and whichever one most enhances the individual’s survival and ability to reproduce survives at the expense of the others. In sexual species, mutations can join the same genomic team, because of genetic exchange. Sex makes evolution cumulative.
Other species with culture but no exchange are like asexual beings: they cannot accrete, combine, and accumulate. Chimpanzees are like this. They are highly cultural in the sense that they teach one another skills, parent their offspring, and consequently develop idiosyncratic traditions within groups. They even make technologies, by choosing rocks to crack nuts, by fashioning twigs to fish for termites. But because chimps do not compare notes or exchange inventions among troops, their ideas cannot have sex and they do not experience progressive cultural change or build increasingly elaborate combinations of ideas as humans do.
Homo erectus, the inventors of the hand axe, probably were like this. Clearly, the tradition of how to transform a rock into a tool was passed down from one generation to the next. Their Eurasian descendants, the Neanderthals, had enormous brains—bigger than modern man’s—and no doubt had even richer culture. Neanderthals buried their dead, which implies imagination, and they shared modern man’s peculiar version of the language gene, so they may well have had good linguistic skills. But their technology showed no progress and no combinatorial growth. They lacked one crucial human behavior of today: trade.
We know this because Neanderthal tools were always made from local stone, whereas “modern” humans in Africa began transporting exotic materials—obsidian, jasper, sea-shells—across great distances 100,000 years ago. People had discovered exchange, so our culture had become sexual, and the combinatorial, progressive explosion could begin. We somehow got over the hurdle that defeated every other social species, from ants to chimps, and learned to trust strangers.
Since ancient times, the exchange of ideas and goods has fueled innovation. Trade, not necessity, is the mother of invention. More thinking and development comes during times of prosperity than desperation. Look at the great bursts of creativity in human history and why they occurred when and where they did: America in the 20th century, Britain in the 19th, Holland in the 17th, Italy in the 15th, China in the 11th, Arabia in the 9th—and before that Rome, Egypt, Greece, India, Phoenicia, and Sumeria. Even the invention of agriculture itself, 10,000 years ago in Syria, happened at a place where hunter-gatherer trade routes met.
In every case it was openness to exchange, within and among nations, that drove innovation (and predation by chiefs, priests, and thieves that shut it down). The same is true today. Countries that open their borders to the free exchange of goods and services and ideas and innovations flourish, while those that cut themselves off and seek economic self-sufficiency stagnate. Compare South and North Korea.
But now, thanks to the Internet, ideas can meet and mate globally and instantaneously like never before. What else is crowdsourcing but working with one another? The cross-fertilization of ideas between, say, Asia and Europe that once took years, decades, or centuries can now happen in minutes while Australia, the Americas, and Africa eavesdrop. The cloud is for everybody, whereas in the old days the sharing of ideas was reserved for the privileged elite. There is, as Stanford economist Paul Romer has argued, not even a theoretical limit to the number of combinations of atoms and electrons we can devise, and the rate at which we devise them is bound to accelerate.
Fasten your seatbelts.
In his TEDGlobal talk Matt Ridley, author of The Rational Optimist, asked the question, “What happens when you cut people off from the ability to exchange?” His answer was that technological progress not only slows down, but actually regresses because isolated groups no longer have the advantages of trade. Look at Tasmania. Before sea levels began rising some 12,000 years ago, the island we now know as Tasmania was actually connected to mainland Australia by a low land mass over which people would travel to trade fishing secrets and equipment, bone tools, and specialized skills. When the physical connection to the mainland was severed, some 4,000 island dwellers began living life in isolation. As generations came and went, the Tasmanians did not take part in the advances being made among the mainland tribes. They lost the ability to make bone tools, boats, and fishing equipment. Eventually, they forgot how to fish altogether. Why? As Ridley says, “The small population was not large enough to maintain the specialized skills necessary to keep the technology they had.”