Citing our ability to be creative, trade, and learn from one another, Matt Ridley in the WSJ explains why we have risen above the other animals.  The answer?  Innovation:

The answer lies in a new idea, borrowed from economics, known as collective intelligence: the notion that what determines the inventiveness and rate of cultural change of a population is the amount of interaction between individuals. Even as it explains very old patterns in prehistory, this idea holds out hope that the human race will prosper mightily in the years ahead—because ideas are having sex with each other as never before.

The more scientists discover, the bigger the evolution puzzle has become. Tool-making itself has now been pushed back at least two million years, and modern tool kits emerged very gradually over 300,000 years in Africa. Meanwhile, Neanderthals are now known to have had brains that were bigger than ours and to have inherited the same genetic mutations that facilitate speech as us. Yet, despite surviving until 30,000 years ago, they hardly invented any new tools, let alone farms, cities and toothpaste. The Neanderthals prove that it is quite possible to be intelligent and imaginative human beings (they buried their dead) yet not experience cultural and economic progress.

Scientists have so far been looking for the answer to this riddle in the wrong place: inside human heads. Most have been expecting to find a sort of neural or genetic breakthrough that sparked a “big bang of human consciousness,” an auspicious mutation so that people could speak, think or plan better, setting the human race on the path to continuous and exponential innovation.

I am reminded of book 1 of Aristotle’s Politics in the next paragraph:

Dense populations don’t produce innovation in other species. They only do so in human beings, because only human beings indulge in regular exchange of different items among unrelated, unmated individuals and even among strangers. So here is the answer to the puzzle of human takeoff. It was caused by the invention of a collective brain itself made possible by the invention of exchange.

Once human beings started swapping things and thoughts, they stumbled upon divisions of labor, in which specialization led to mutually beneficial collective knowledge. Specialization is the means by which exchange encourages innovation: In getting better at making your product or delivering your service, you come up with new tools. The story of the human race has been a gradual spread of specialization and exchange ever since: Prosperity consists of getting more and more narrow in what you make and more and more diverse in what you buy. Self-sufficiency—subsistence—is poverty.

We need each other, humans do, in order to live the good life.  We come together in communities in order to live better lives than if we were on our own. Subsistence is a part of that, but Aristotle would not stop there.  An interesting essay.  Even if you disagree, read the whole thing.