Christie Wilcox reports via Science.org: Both longhorn crazy ants (Paratrechina longicornis) and humans can figure out how to work together to move an unwieldy object through a series of obstacles. So scientists pitted the two against each other. They had individuals and groups of different sizes of both species maneuver a T-shaped object through holes in walls (as seen in the video above), both of which were scaled to the body size of the participants. This kind of puzzle is hard for ants because their pheromone-based communication doesn’t account for the kind of geometry needed to get the object through the doors. To make the experiments even more comparable, the team also took away the humans’ communication in some of the trials by making them wear sunglasses and masks and forbidding talking and gestures. So the people, like the ants, had to work together without language, relying on the forces generated by their fellow participants to figure out how to move the T-shaped piece.
The groups of ants were much better at solving the puzzle than individual ants, exhibiting what the researchers described as “emergent” collective memory — an intelligence greater than the sum of its parts. The groups of humans, on the other hand, often didn’t do better when working together, especially if they weren’t allowed to talk. In fact, multiple people sometimes performed worse than individuals — and worse than the ants. The researchers posit that, in the absence of the ability to discuss and debate, individuals attempt to reach a consensus quickly rather than fully assessing the problem. This “groupthink,” they suggest, leads people toward fruitless “greedy” efforts where they directly pull the T toward the gaps in the wall, rather than the less obvious, correct solution of pulling the object into the space between first. Whereas the ants “excel in cooperation,” they write, humans need to be able to talk through their reasoning to avoid simply going with what they think the crowd wants.
The study has been published in the journal Proceedings of the National Academy of Sciences.