The Edge's Annual Question is a great compilation of brief effusions from science groupies like me. This year the question was
What scientific concept would improve everybody's cognitive toolkit?
My answer was this:
Brilliant people, be they anthropologists, psychologists or economists, assume that brilliance is the key to human achievement. They vote for the cleverest people to run governments, they ask the cleverest experts to devise plans for the economy, they credit the cleverest scientists with discoveries, and they speculate on how human intelligence evolved in the first place.
They are all barking up the wrong tree. The key to human achievement is not individual intelligence at all. The reason human beings dominate the planet is not because they have big brains: Neanderthals had big brains but were just another kind of predatory ape. Evolving a 1200-cc brain and a lot of fancy software like language was necessary but not sufficient for civilization. The reason some economies work better than others is certainly not because they have cleverer people in charge, and the reason some places make great discoveries is not because they have smarter people.
Human achievement is entirely a networking phenomenon. It is by putting brains together through the division of labor - through trade and specialisation - that human society stumbled upon a way to raise the living standards, carrying capacity, technological virtuosity and knowledge base of the species. We can see this in all sorts of phenomena: the correlation between technology and connected population size in Pacific islands; the collapse of technology in people who became isolated, like native Tasmanians; the success of trading city states in Greece, Italy, Holland and south-east Asia; the creative consequences of trade.
Human achievement is based on collective intelligence - the nodes in the human neural network are people themselves. By each doing one thing and getting good at it, then sharing and combining the results through exchange, people become capable of doing things they do not even understand. As the economist Leonard Read observed in his essay "I, Pencil' (which I'd like everybody to read), no single person knows how to make even a pencil - the knowledge is distributed in society among many thousands of graphite miners, lumberjacks, designers and factory workers.
That's why, as Friedrich Hayek observed, central planning never worked: the cleverest person is no match for the collective brain at working out how to distribute consumer goods. The idea of bottom-up collective intelligence, which Adam Smith understood and Charles Darwin echoed, and which Hayek expounded in his remarkable essay "The use of knowledge in society", is one idea I wish everybody had in their cognitive toolkit.
Some of the other answers were great, including this from Sue Blackmore, of which this is an extract (and which should be compulsory reading for climate scientists):
The phrase "correlation is not a cause" (CINAC) may be familiar to every scientist but has not found its way into everyday language, even though critical thinking and scientific understanding would improve if more people had this simple reminder in their mental toolkit.
One reason for this lack is that CINAC can be surprisingly difficult to grasp. I learned just how difficult when teaching experimental design to nurses, physiotherapists and other assorted groups. They usually understood my favourite example: imagine you are watching at a railway station. More and more people arrive until the platform is crowded, and then - hey presto - along comes a train. Did the people cause the train to arrive (A causes B)? Did the train cause the people to arrive (B causes A)? No, they both depended on a railway timetable (C caused both A and B).
I soon discovered that this understanding tended to slip away again and again, until I began a new regime, and started every lecture with an invented example to get them thinking.
"Right", I might say "Suppose it's been discovered (I don't mean it's true) that children who eat more tomato ketchup do worse in their exams. Why could this be?" They would argue that it wasn't true (I'd explain the point of thought experiments again). "But there'd be health warnings on ketchup if it's poisonous" (Just pretend it's true for now please) and then they'd start using their imaginations.
"There's something in the ketchup that slows down nerves", "Eating ketchup makes you watch more telly instead of doing your homework", "Eating more ketchup means eating more chips and that makes you fat and lazy". Yes, yes, probably wrong but great examples of A causes B - go on. And so to "Stupid people have different taste buds and don't like ketchup", "Maybe if you don't pass your exams your Mum gives you ketchup". And finally " "Poorer people eat more junk food and do less well at school".