Bumblebees possess an amazing form of collective intelligence that was once thought to be specific to humans

Researchers have recently demonstrated that bumblebees possess an amazing form of collective intelligence that was previously thought to be specific to humans. During laboratory experiments, bumblebees have demonstrated their ability to adopt highly complex behaviors that go beyond their individual capacity for innovation and that can only be transmitted through social learning. This indicates an advanced social learning capacity that we were not previously aware of.

In humans, almost all behavior is based on knowledge that requires several generations of improvement. Our current knowledge depends in one way or another on collective knowledge accumulated over centuries, according to what is called “cumulative culture.” For example, not all components of a computer or smartphone were invented by one person. Instead, many generations of inventors and scientists worked collectively to get where we are today.

It has been suggested that cumulative culture requires higher-level forms of social learning (such as imitation, teaching or skill transmission), which were previously thought to be specific to humans. However, studies have recently revealed evidence suggesting the existence of a form of cumulative culture in some animals. In fact, the concept of cumulative culture implies that beneficial change (or innovation) regarding a particular behavior must be transmitted socially.

This type of behavior has been observed, for example, in passenger pigeons. In fact, researchers have previously shown that when pairs of passenger pigeons have to return home from different locations, they more quickly find the most efficient routes when one member of the pair is exchanged regularly. This means that pairs that always consist of the same members or birds that travel alone are less quick to find the best routes. This suggests that there are useful “innovations” brought by new members that are passed on to other birds.

However, it has not yet been clear whether these innovations are transmitted in animals through some form of cumulative cultivation, or whether they can be acquired individually. Indeed, “this threshold, which often includes stipulating the impossibility of renewal during one's lifetime, is considered by some to be a fundamental difference between human and non-human cognition.” to explain Researchers from Queen Mary University of London and the University of Sheffield (in England) in their new study on this topic, which was published in the journal nature.

On the other hand, research on higher forms of cognition in animals has been mostly conducted on primates, due to their brain size and genetic closeness to humans. As part of their work, the English researchers explored this question in bumblebees, due to their advanced social behaviors.

A form of cumulative culture?

Other experiments have previously demonstrated that bees (the same family as bumblebees, Apidae) can acquire complex and unnatural behaviors through social learning. For example, they are able to solve puzzles by learning from each other, in order to obtain food. They can also improve the behavior (puzzle-solving technique) of the initial demonstrator, indicating more advanced cognitive abilities than previously thought.

However, previous research has generally included behaviors that bees can acquire individually. That is, these were not necessarily innovative behaviors transmitted through some form of cumulative culture. To determine whether bumblebees (Bombus terrestris) are able to acquire this type of behavior, the researchers in the new study developed a two-step puzzle system.

This is a design inspired by a puzzle box previously tested on Goffin's Cockatoo (Kakatoa joviniana) to evaluate their ability to solve problems. The birds were challenged to open a box locked with five interconnected locks, which could only be opened in a specific order. Rewards were only awarded after the last lock was unlocked.

” Our hypothesis is that this degree of temporal and spatial separation between executing the first step of a behavior and the reward would make it very difficult, if not impossible, for the bumblebee [sans formation préalable] Create a lasting connection between that initial action and the ultimate reward », explain the researchers. In the illustration below, bumblebees can access the reward (yellow circle) by pressing the red tab, but only after pressing the blue tab.

In other words, it was almost impossible to understand the task imposed on individual bumblebees. Therefore, the researchers first taught the “demonstrators” how to solve the puzzle, and offered them a reward (a sweet solution) after the first step, to motivate them. After this training phase, demonstrators were introduced to the puzzle box along with other naive bumblebees. It turns out that the protesters “taught” the other bees to open the box in two steps and get the reward.

These results suggest that bumblebees can acquire highly complex social behaviors, beyond their individual ability to innovate. Furthermore, the colony was unable to open the puzzle box in the absence of “qualified” demonstrators. ” This finding challenges a common view in the field: that the ability to socially learn behaviors that cannot be devised through individual trial and error is unique to humans. », concluded the team.

source : nature