Certain wasps may be able to understand associations and unknowns about their surroundings, according to a recent study. The research signifies the first evidence of transitive inference in a non-vertebrate animal. Transitive inference or TI, is a fundamental portion of deductive reasoning and until recently was thought to be a trademark of human intellect. With TI, we can understand different relationships and reason certain outcomes with just bits and pieces of information. Researchers have found that this skill extends to other vertebrate animals like monkeys and even fish.
There has been only one study on TI ability in honeybees published and the results show that bees are not adept of this deductive skill. Honeybees have small nervous systems which could explain the cognitive limitations that prevent bees from being able to perform TI.
Undeterred by the results of the honeybee study, researchers from the University of Michigan turned to paper wasps to test for TI in invertebrates. Wasps have the same size of the nervous system as honeybees, but a complex prosocial nature sets wasps apart from honeybee colonies. This led Elizabeth Tibbetts, an evolutionary biologist, to wonder if the wasp's social skills give the insect an advantage over honeybees when it comes to inferring unknowns. Two species of paper wasps, Polistes dominula and Polistes metricus, were used in the study, and the researchers collected paper wasp queens.
The wasps were brought back to the lab and trained to differentiate between principle pairs of colors by associating one pair of colors with an electric shock. Next, the wasps were given a choice between new pairs of colors. The researchers found that the wasps used a kind of transitive inference to sort and organize the colors and essentially choose between the pairs.
"We're not saying that wasps used logical deduction to solve this problem, but they seem to use known relationships to make inferences about unknown relationships," Tibbetts said. "Our findings suggest that the capacity for complex behavior may be shaped by the social environment in which behaviors are beneficial, rather than being strictly limited by brain size."
Wasps have a completely different hierarchy and social structure compared to honeybees. Honeybee colonies have a single queen whereas wasp colonies have several foundresses, each able to reproduce. Foundresses compete against each other, and a worker wasp may need to rely on TI to navigate the complex realities and social relationships. "This study adds to a growing body of evidence that the miniature nervous systems of insects do not limit sophisticated behaviors," said Tibbetts.
