Ed Yong over at National Geographic's Not Exactly Rocket Science (via Jennifer Ouellette):
In 1907, Sir Francis Galton asked 787 villagers to guess the weight of an ox. None of them got the right answer, but when Galton averaged their guesses, he arrived at a near perfect estimate. This is a classic demonstration of the “wisdom of the crowds”, where groups of people pool their abilities to show collective intelligence. Galton’s story has been told and re-told, with endless variations on the theme. If you don’t have an ox handy, you can try it yourself with beans in a jar.
To Iain Couzin from Princeton University, these stories are a little boring. Everyone is trying to solve a problem, and they do it more accurately together than alone. Whoop-de-doo. By contrast, Couzin has found an example of a more exciting type of collective intelligence—where a group solves a problem that none of its members are even aware of. Simply by moving together, the group gains new abilities that its members lack as individuals.
Couzin has spent his whole career studying animals that move in shoals, flocks and swarms. His early work involved ants and locusts but when he started his own lab at Princeton, he thought he’d upgrade to a smarter group-living species. Unfortunately, he ended up with the golden shiner—a small, bland, minnow-like fish that’s dumb beyond the telling of it.