This book will teach you a new way to think about our past, present, and future.

We all have little models in our heads of how the world works. Those models needn’t be complicated. For example, one might be that if you push on a rock and it moves a little, then if you push harder it’ll move more. We then reason by analogy that if a government is trying to do something, and if a little money does a little good, then a lot of money will do even better. Such models can work, but they also often fail. For example, the United States has spent a lot of money on integration. Today, housing there is about as segregated by skin color as it was in 1968. Britain, too, has spent a lot on integration. Today, segregation by income and education there is about the same as it was in 1970. Australia has also pushed integration. Today, opportunity there is about the same as it was 40 years ago. If we really understood how we work, how come so much effort has made so little difference?

Our usual stories of how we work focus on individuals, not groups. We often imagine, for instance, that if most of us want something to change then that change must happen. That works in reverse too. We imagine that if something changes then most of us must first have wanted it to change. For example, many of us imagine that women’s lives have changed over the past two centuries because a few heroic women got together and made them change. But if that’s all it took why didn’t some heroic women do that thousands of years ago?

A group needn’t behave the same way as its set of individuals—the whole needn’t be the sum of its parts. A group can act differently than any of its parts might wish to act because the group itself can, in a sense, be an actor. That super-actor is the network that the various separate actors form. What it ‘wants’ is often more important than what any of its parts might want. It’s as if there’s one kind of physics for each of us, but a whole different physics for us together. If you run off a cliff, you’ll fall. But if a cartoon runs off a cliff, it can’t fall. It first has to notice that it’s in midair, then it has to look at the camera for that last desperate second, then it falls.

Today, scientists in a new field called ‘complex systems’ are giving concrete meaning to that idea of group physics. Understanding that physics is especially important today because our technology is now changing so fast that we need more accurate models about how we work simply to survive our coming changes. Those potential changes likely won’t be much like the usual calamities or utopias. They have little to do with climate change, nuclear terror, or shinier doodads. They’re deep changes in how we work together. Now, normally when you hear that kind of thing some political talk follows. Often the next sentence starts with ‘Join me’ and ends with some slogan like ‘Moral Rebirth,’ ‘Communist Utopia,’ or perhaps even ’Thousand-Year Reich.’ But this book is an attempt at a work of science. It has little to do with political change, self-sacrifice, or central control. It’s about material things and material life and the network forces that move us without our even being aware of them. It’s about how we swarm.