Ants have proven to be superior to humans in a maze experiment for solving group problems, specifically for carrying large loads that far exceed their own dimensions.
Researchers at the Weizmann Institute of Science have studied which of the two species performs better at this task and publish surprising results in the journal PNAS. “We have shown that ants that act in groups are more intelligent, that for them the whole is greater than the sum of its parts. In contrast, forming groups does not expand the cognitive abilities of humans,” explains Professor Ofer Feinerman, lead author, in a statement.
To allow a comparison between two such disparate species, the research team created a real-life version of the “piano puzzle,” a classic computational problem from the fields of motion planning and robotics that deals with possible ways of moving an unusually shaped object (for example, a piano) from point A to point B in a complex environment.
Instead of a piano, participants were given a large T-shaped object that they had to maneuver through a rectangular space divided into three chambers connected by two narrow slits.
The researchers created two sets of mazes that differed only in size, to match the dimensions of the ants and humans, as well as groups of different sizes. Recruiting study participants was easier in the case of the humans, who volunteered simply because they were asked to participate and probably because they liked the idea of a competition. Ants, by contrast, are far from competitive. They joined in because they were tricked into thinking the heavy load was a juicy edible morsel they were carrying back to their nest.
The ants chosen to compete against Homo sapiens were Paratrechina longicornis. They are named for their long antennae, though they are sometimes called “crazy ants” for their tendency to run. This well-known species of black ant, about 3 mm long, is common throughout the world. In Israel they are especially frequent along the coast and in the south of the country.
The ants tackled the maze challenge in three combinations: a single ant, a small group of about seven ants, and a large group of about 80. The humans handled the task in three parallel combinations: a single person, a small group of six to nine individuals, and a large group of 26.
To make the comparison as meaningful as possible, groups of humans were in some cases ordered to avoid communicating through speech or gestures, even wearing surgical masks and sunglasses to hide their mouths and eyes. In addition, the human participants were asked to hold the load only by handles that simulated the way ants hold it. The handles contained gauges that measured the pulling force applied by each person during the attempt.
The researchers repeated the experiment numerous times for each combination, then meticulously analyzed the videos and all the advanced tracking data while using computer simulations and various physical models.
Unsurprisingly, the humans’ cognitive abilities gave them an advantage in the individual challenge, where they resorted to calculated strategic planning, easily outperforming the ants.
THEY ACT TOGETHER IN A CALCULATED AND STRATEGIC MANNER
However, in the group challenge the picture was completely different, especially for the larger groups. Not only did the ant groups perform better than individual ants, but in some cases they performed better than humans. Groups of ants acted together in a calculated and strategic manner, exhibiting a collective memory that helped them persist in a particular direction of movement and avoid repeated mistakes.
The humans, in contrast, failed to significantly improve their performance when acting in a group. When communication between group members was restricted to resemble that of ants, their performance even declined compared to that of individuals. They tended to opt for “greedy” solutions, which seemed attractive in the short term but not beneficial in the long term, and, according to the researchers, they opted for the lowest common denominator.
“An ant colony is actually a family,” Feinerman says. “All the ants in the nest are siblings and have common interests. It’s a close-knit society in which cooperation far outweighs competition. That’s why an ant colony is sometimes referred to as a superorganism — a kind of living body made up of multiple “cells” that cooperate with each other.
“Our findings validate this view. We’ve shown that ants that act in groups are smarter, that for them the whole is greater than the sum of its parts. In contrast, forming groups does not expand the cognitive abilities of humans. The “wisdom of the crowd,” which has become so popular in the age of social media, did not come to the fore in our experiments.”
