Human exceptionalism

It seems to be something of  a fad to claim that humans aren't actually exceptional. Other animals can think and learn and plan and communicate with each other, there's nothing special about us, at least no more than the extent to which every species is unique, yadda yadda. I think this is an utterly vapid argument. Sure, every species is unique, but our impact on the planet is vastly greater than that of any other organism. Yes of course, photosynthetic organisms created and sustain our oxygen-rich atmosphere, but that's been the case for more than 2 billion years. That's the stable background of life on earth. We've created a radical transformation of the planet in just a couple of centuries, and that was possible because of an attribute of our that is absolutely unique. 

The oldest known fossils of people like us, Homo sapiens, are about 300,000 years old. Or rather, I should say that those fossilized bones look like our bones, but we don’t know for sure if their brains were quite like ours. Scientists who study human pre-history disagree about that. The most important differences between us and other apes – or for that matter all other creatures -- are behavioral, and scientists disagree about whether the behavioral repertoire of Homo sapiens developed gradually starting with those 300,000 year old people, or depended on genetic changes that happened later.

For our purposes, it doesn’t matter. By 80,000 years ago or so, archaeological sites in southern Africa show people using stone blades and bone tools, making ornaments, and trading over long distances. By 50,000 years ago, people were burying their dead in elaborate graves, making diverse artifacts, and otherwise showing signs of more rapid cultural evolution. This one-directional trend toward more complex technology and elaborate behaviors is unique to humans.

Chimpanzees can invent new ways of doing things, for example stripping leaves off of twigs and inserting them into anthills or termite nests to extract the inhabitants; or cracking nuts with a rock or a stick. Others in the troop may observe and imitate these behaviors, and the result is a rudimentary form of what social scientists call culture -- behaviors characteristic of a particular group within a species, transmitted by social learning rather than inherited instinct.

But chimpanzees have never invented anything much more complicated than hitting a nut with a rock. They have never built on an invention to develop an even more useful one, such as shaping a rock for a purpose. And whatever inventions they do come up with are unlikely to spread to other troops and may not survive long. If a year or two passes with a poor nut crop, the next generation won’t learn nut cracking and the technology will be lost. Apart from a few feeding techniques, greeting rituals or playful behaviors, all of which may come and go, chimpanzee societies have stayed pretty much the same for millions of years.

Humans are certainly cleverer than chimps. As individuals, we’re better at solving puzzles and more inventive. But it isn’t our individual big brains that drive technological innovation and cultural complexity, it’s our extraordinary capacity for collaboration, for teaching and learning from each other, and for creating collective memory. This is all possible because of one thing we can do that no other animal can. We can talk.

Other animals, including chimps, make meaningful sounds. But for a chimp or any other animal, a given sound always has the same meaning, such as a predator alarm, a threat, or a solicitation for sex. Humans effortlessly string together thousands of different sounds – words – to create completely novel meanings. These meaning are not only more complex, but also of many kinds of which other animals are incapable.

Since we don’t know what kinds of names people had 50,000 years ago, I’ll just imagine a couple of characters from the B.C. comic strip. Not only can Grog say “Watch out, there’s a snake!” Jane can answer back, “Don’t worry, that kind is harmless,” then Jane can say that she’s going to kill it and have it for dinner, ask Grog to help by throwing a rock at it to drive it from its lair, and tell Grog the best way to cook it.

Grog starts with something a chimp can say, but Jane has knowledge about the world that Grog did not, about that particular kind of snake, which she shares with Grog. She then conveys an intention, makes a request, and gives Grog instructions on how to perform a useful task. She has a store of information and ways of working that she has now transferred from her head into Grog’s. Language doesn’t just represent or describe reality, it creates reality, in this case a cooperative action that results in a dead snake and a dinner dish, as well as a better informed Grog.

Theorists have noticed something else that is essential about language. It may be that it helps create trust between people, but it could not have evolved and become a pervasive human attribute if people couldn’t already trust each other. Other animals can’t fake their vocalizations – they cannot lie to each other. The threat warning is an instinctive reaction. Chimpanzees do sometimes deceive each other, but even if they could fake a vocalization the consequences would not be very severe. But if Jane is lying about the snake being harmless, Grog could wind up dead. Sure, people lie, but human society would be impossible if consequential lies weren’t the exception. We have to trust each other, and for the most part our trust is rewarded. Maybe other apes never acquired language because they couldn’t trust each other enough to make it evolutionarily adaptive, while humans are just more cooperative by nature.

Language is all the more useful because we like to teach each other, and we like to learn from each other. Children expect their parents and other adults to teach them, and adults do teach children as naturally as they eat and drink. They do that partly by example, partly by demonstration, and partly by talking, which also makes example and demonstration much more effective. Language is the store of real world knowledge, technology, social practices and norms that allows culture to pass down from generation to generation, building ever more knowledge and complexity on the existing base.

That’s what’s called the “cultural ratchet.” When people learn something, or how to do something, unlike chimps, they collectively remember. Once we learned how to crack nuts, we never forgot. Instead, we got better and better at it. We learned how to manufacture hunting weapons, and clothe ourselves and eventually, 10,000 years ago or so, to plant crops and domesticate animals.

All of human history, from the invention of stone tool making by species ancestral to Homo sapiens until the invention of agriculture, is called the Paleolithic, or Old Stone Age. With agriculture came the Neolithic, or New Stone Age revolution. For a million years of hunting and foraging, our ancestors lived in small bands that moved around to follow the available resources. They didn’t accumulate much stuff, they didn’t store surpluses for very long, and they were probably quite egalitarian. But with the Neolithic revolution people settled down, in towns and then cities. They stored grain and other surplus produce in large quantities and doled it out over time. They developed specialized jobs, and caste hierarchies. The first states emerged, typically ruled by an alliance between a priestly caste and a warrior caste led by a king.

Technological innovation accelerated. People learned to construct elaborate permanent dwellings. Soon they learned to smelt copper, then bronze, and finally iron. The learned to spin thread weave cloth. They built boats and wheeled vehicles. Early on, they invented writing and then in 1440, the printing press, enabling mass production of documents and books and encouraging more wide-spread literacy. At about the same time Europeans started building sailing ships that could traverse the oceans, and less than 100 years later the entire globe was known and knitted together by trade, and by conquest. The late 1700s saw the first really practical steam engines, and in the 1800s people put them on wheeled vehicles and the railroads came into being. Agriculture became more and more productive with the invention of the iron plow pulled by animals, and then the exchange of food crops among formerly isolated land masses.

 

Then, in the 1800s, for the first time, the human lifespan increased - in fact it doubled in less than 100 years in the 20th Century -- and the human population exploded, even as we fueled an ever more rapid technological revolution by burning fossil fuel, to run machinery and then to generate electricity. Now, if we don't stop doing that, we're going to suffer horribly, along with most of the rest of life on earth. Yeah, we're exceptional.