Honeybees That Solve Math Problems Challenge Supremacy of Human Brains

Maybe math isn't so hard after all.

Honeybees may have sesame seed-sized brains, but they’re way smarter than scientists suspected. Stunning new research shows they can even do simple math, suggesting that our bigger brains aren’t necessarily better or especially unique.

In the paper, published Wednesday in Science Advances, researchers described how they used color-coded shapes to train 14 honeybees to do simple arithmetic, as the video above details. When presented with a math problem and two possible solutions (one correct, one incorrect), these trained bees chose the correct option between 63.6 and 72.1 percent of the time — significantly more often than if they just chose at random.

This development calls the relationship between brain size and intelligence into further question, and it even makes scientists question whether math is really as “difficult” as we think.

“In the current study, the bees not only succeeded in performing these processing tasks but also had to perform the arithmetic operations in working memory,” write the study’s authors, led by Scarlett Howard, Ph.D., a postdoctoral researcher at the French National Center for Scientific Research who conducted the research as a Ph.D. student at RMIT University in Australia. Howard was also the first author of a 2018 study showing that honeybees grasp the abstract mathematical concept of zero.

Scientists trained bees to do basic math, complicating what we know about brain size and brain power.
Scientists trained bees to do basic math, complicating what we know about brain size and brain power.

Of course, these honeybees didn’t solve math problems like we do, with the questions written out in numerals with plus and minus symbols between them. Instead, they were taught to recognize colors as different operations — blue for addition and yellow for subtraction. Three blue shapes, for instance, meant the correct answer would be one greater — four. Three yellow shapes, meanwhile, meant the correct answer was one fewer — two.

The researchers write that these results are exciting because arithmetic is a complex cognitive process, requiring the bees to use both long-term memory to remember rules and short-term working memory to deal with the figures in front of them.

In a Y-shaped maze, the bees were rewarded with sugar water for choosing correctly and were punished with a bitter quinine solution for choosing incorrectly. Since bees naturally want to seek food, they kept returning to forage and learn. The scientists observed each bee do this 100 times, as each one continuously became more accurate.

Scientists trained bees to do addition (bottom) and subtraction (top) based on the color of shapes.
Scientists trained bees to do addition (bottom) and subtraction (top) based on the color of shapes.

Once they’d been trained, the bees were tested dozens more times, and in the end, they guessed correctly most of the time, regardless of whether they were adding or subtracting.

The researchers argue these results generally show the brain areas primates use for math — the posterior parietal cortex and the prefrontal cortex — are not necessary for bees. While math itself may not be crucial to bees’ survival, they write, the simultaneous use of long- and short-term memory has an evolutionary purpose when it comes to tasks like remembering the size, shape, and petal arrangement of flowers that are more nutritious.

“This important step in combining the arithmetic and symbolic learning abilities of an insect has identified numerous new areas for future research and also poses the question of whether these complex numeric understandings may be accessible to other species without large brains, such as the honeybee,” the authors write.

Based on the results of this study, they argue that neither language nor numerical abilities are required for an animal to learn to do math. Maybe, it suggests, humans aren’t so special after all.

Abstract: Many animals understand numbers at a basic level for use in essential tasks such as foraging, shoaling, and resource management. However, complex arithmetic operations, such as addition and subtraction, using symbols and/or labeling have only been demonstrated in a limited number of nonhuman vertebrates. We show that honeybees, with a miniature brain, can learn to use blue and yellow as symbolic representations for addition or subtraction. In a free-flying environment, individual bees used this information to solve unfamiliar problems involving adding or subtracting one element from a group of elements. This display of numerosity requires bees to acquire long-term rules and use short-term working memory. Given that honeybees and humans are separated by over 400 million years of evolution, our findings suggest that advanced numerical cognition may be more accessible to nonhuman animals than previously suspected.

Media via RMIT University, Science Advances/ Howard et al