Shawn at Anecdote gives a couple of examples of complexity. He uses these to convey how difficult it is to make reliable predictions of complex systems.
When I talk about complexity to clients I mention that complex systems are impossible to predict in detail especially as your forcast extends into the future. I point out that there are so many connections among the objects affecting the system and many of the cause and effect relationships are non-linear (a small thing can have a big impact and vice versa). Every now and then someone will say “but if you could work out all those connections you could predict the outcome.” And this is where I will tell them the chessboard story.
The legendary information scientist, Claude Shannon, calculated how many possible moves there are on a chessboard. It’s a finite system of 64 squares, 32 pieces, 6 movement patterns. The number is big and equates to the number of milliseconds the world has been in existence. And that’s for a simple system. Imagine the possibilities in a social system where the objects have free will.
One aspect of human complexity is that our brains are highly developed to simplify what we see – giving rise to an impressive series of cognitive biases. So we usually don’t recognise the complexity of what we’re up against…