The Rational Optimist: How Prosperity Evolves

by Matt Ridley

Look again at the hand axe and the mouse. They are both ‘man-made’, but one was made by a single person, the other by hundreds of people, maybe even millions. That is what I mean by collective intelligence. No single person knows how to make a computer mouse. The person who assembled it in the factory did not know how to drill the oil well from which the plastic came, or vice versa. At some point, human intelligence became collective and cumulative in a way that happened to no other animal.

Exchange is to cultural evolution as sex is to biological evolution.

This is what prosperity is: the increase in the amount of goods or services you can earn with the same amount of work.

Reciprocity means giving each other the same thing (usually) at different times. Exchange – call it barter or trade if you like – means giving each other different things (usually) at the same time: simultaneously swapping two different objects.

Collaboration between unrelated strangers seems to be a uniquely human achievement. In no other species can two individuals that have never before met exchange goods or services to the benefit of each other, as happens routinely each time you visit a shop or a restaurant or a website.