Group decision-making better in ants compared to humans: Study

New Delhi: A group of ants fared better than humans when confronted with a task of manoeuvring large loads through a maze, displaying strategy and collective memory that helped them persist and avoid mistakes, a study has found.

Humans, on the contrary, failed to significantly improve their performance when acting in groups, said researchers from the Weizmann Institute of Science, Israel.

"While ants perform more efficiently in larger groups, the opposite is true for humans," the authors wrote in the study published in the journal Proceedings of the National Academy of Sciences.

"Forming groups did not expand the cognitive abilities of humans. The famous 'wisdom of the crowd' that's become so popular in the age of social networks didn't come to the fore in our experiments," said lead researcher Ofer Feinerman, a professor at the institute's Department of Complex Systems.

The findings shed new light on group decision-making and validated the perception of ants that "for them, the whole is greater than the sum of its parts," he said.

"That's why an ant colony is sometimes referred to as a super-organism, sort of a living body composed of multiple cells that cooperate with one another," he added.

Two sets of mazes were created, differing only in size, to match the dimensions of ants and humans. The ants tackled the maze challenge in three combinations -- a single ant, a group of seven ants and a group of 80 -- while the humans tackled it as a single person, a group of six to nine people and a group of 26.

To make meaningful comparisons, humans were told to avoid communicating by speaking or through gestures and were given masks and sunglasses to conceal their mouths and eyes. Video recordings and tracking data were analysed using computer and physics models.

While performing the task individually, the cognitive abilities of humans gave them an edge as they resorted to calculated, strategic planning, easily outperforming the ants, the researchers said.

In the group challenge, however, the picture was completely different, they said, especially for the larger groups.

Not only were groups of ants seen performing better than individual ants but in some cases, their performance was better than humans.

The ants acted together in a calculated and strategic manner, exhibiting collective memory that helped them persist in a particular direction of motion and avoid repeated mistakes, the study found.

"We find that although individual ants cannot grasp the global nature of the puzzle, their collective motion translates into emergent cognitive skills," the authors wrote.

Further, under restricted communication, the performance of humans in a group was seen to drop to levels worse than that in an individual.

They tended to opt for "greedy" solutions -- attractive in the short-term but not beneficial in the long-term -- and the lowest common denominator, the researchers said.

"An ant colony is actually a family. All the ants in the nest are sisters and they have common interests. It's a tightly knit society in which cooperation greatly outweighs competition," Feinerman said.

The ant species Paratrechina longicornis were involved in the study to compete against humans.

The researchers said that while the idea of competition might have enticed humans to participate in the study, the ants were "far from competitive" but joined only because they were misled into thinking that the heavy load they were transporting into their nest was "a juicy edible morsel".