The Wisdom and/or Madness of Crowds

About the game

It starts with Isaac Newton losing a fortune in the South Sea Bubble of 1720, and the question he left behind: if one of the great minds of his time could be swept up by the madness of a crowd, what chance do the rest of us have? The guide's answer is that you cannot understand a crowd without understanding the network of people inside it.

So you build one. In the first chapter you draw friendships between little round people, by dragging a line between two of them and scratching one out to cut it. In the next you let something spread through the network, a rumour or a habit, and see how a few extra connections turn a trickle into a flood. A "complex contagion", one that takes several exposures before it catches, spreads very differently from a simple one. Later chapters look at bonding and bridging (the closeness inside a group against the links between groups), and at the famous "small world" effect that connects strangers in a few steps. A sandbox at the end lets you build any network you like and set it off.

Nicky Case made it in 2018, in the same "explorable explanation" style as The Evolution of Trust. Boxes marked with a question mark have bonus notes, and a list of references leads to the research behind each part.

Playing it here

Click Play now and then the arrow button. The numbers along the bottom jump between chapters; the star opens the sandbox. In the sandbox, press 1 to add a healthy person and 2 to add an infected one where the pointer is, Space to pick one up and move it, and Delete to remove it. On the Portuguese pages of this site the game opens in Brazilian Portuguese, using the fan translation included in the author's repository; on the English pages it is in English. Nothing is saved.

A few things worth knowing

It uses sound. There is music and a few small effects; the speaker icon at the bottom left turns it off.

Try cutting a connection that matters. The most interesting moments come from watching a spread change after one cut.

Credits and licence

Created by Nicky Case and dedicated to the public domain under Creative Commons Zero. The music is "Friends 2018" and "Friends 2068" by Komiku (CC0). Sound effects come from Freesound: pencil scratching by JasonElrod, "can't cut connection" by johnnypanic, windchimes by InspectorJ, moving a person by ermfilm and clear-all by dogfishkid are licensed under Creative Commons Attribution (CC BY); the rest are CC0. The game uses Howler.js, MinPubSub and iNoBounce (MIT), and the font Patrick Hand (SIL OFL 1.1). A few images of third parties (two book covers and a map screenshot) were removed from the bonus notes. The licence texts are linked from this page.