“Two, four, six, eight; sag in, don’t wait”. As children, we learn that numbers can be even or odd. And there are many ways to classify even or odd numbers.
We can keep in mind the rule that numbers ending in 1, 3, 5, 7 or 9 are odd while numbers ending in 0, 2, 4, 6 or 8 are even. Or we can divide a number by 2 – where any result is an integer means the number is even, otherwise it must be odd.
Similarly, when dealing with real world objects, we can use concatenation. If we have one unpaired element left over, it means the number of objects is odd.
To date, even and odd classifications, also known as parity classifications, have never been shown in non-human animals. In a new study, published today in the journal Frontiers in ecology and evolutionwe show honey bees can learn to do this.
Why is the parity classification special?
Parity tasks (such as sorting even and odd) are considered abstract and high-level numerical concepts in humans.
Interestingly, humans demonstrate accuracy, speed, language, and spatial relationships bias when classifying numbers as odd or even. For example, we tend to respond faster to even numbers with actions performed by our right hand and odd numbers to actions performed by our left hand.
We’re also faster and more accurate at classifying numbers as even than odd. And research has found that children often associate the word “even” with “right” and “odd” with “left”.
These studies suggest that humans may have learned biases and/or innate biases about even and odd numbers, which may have arisen through evolution, cultural transmission, or combine both.
It’s not clear why parity might be important beyond its use in mathematics, so the origin of these biases remains unclear. Understanding whether and how other animals can recognize (or can learn to recognize) even and odd numbers can tell us more about our own history with parity.
Training bees to learn odd and even
Studies have shown that honey bees can learn to sort numbers, perform simple addition and subtraction, combine symbols with numbers, and relate the concepts of size and quantity.
To teach bees a parity task, we separated individuals into two groups. A person is trained to associate even numbers with sugar water and odd numbers with bitter liquids (quinine). The other group was trained to associate odd numbers with sugar water, and even numbers with quinine.
We trained each bee by comparing odd to even numbers (with cards with 1-10 prints) until they chose the correct answer with 80% accuracy.
Notably, the respective groups learned at different rates. Bees trained to associate odd numbers with sugar water learned faster. Their learning bias towards odd numbers is in contrast to that of humans, who sort even numbers faster.
We then tested each bee on new numbers that were not shown during training. Impressively, they classified new numbers of 11 or 12 elements as odd or even with about 70% accuracy.
Our results show that the miniature brain of honey bees can understand the concepts of odd and even. So, a large and complex human brain consists of 86 billion neurons, and a miniature insect brain with about 960,000 neurons, both of which can sort numbers according to parity. .
Does this mean the parity task is less complex than we previously thought? To find the answer, we turned to bio-inspired technology.
We trained honey bees to choose even numbers. In this video we see the bee examine each card on the screen, before making the correct choice on the even numbered card of 12 shapes.
Create a simple artificial neural network
Artificial Neural Networks are one of the first learning algorithms developed for machine learning. Inspired by biological neurons, these networks are scalable and can solve complex classification and recognition tasks using propositional logic.
We built a simple artificial neural network with only five neurons to perform parity checking. We have given network signals from 0 to 40 pulses, classified as odd or even. Despite its simplicity, the neural network correctly classified the number of pulses as odd or even with perfect accuracy of 100.
This showed us that, in principle, Parity sorting does not require a large and complex human brain. However, this does not necessarily mean that the bee and the simple neural network used the same mechanism to solve the task.
Simple or complicated?
We still don’t know how bees can perform the parity task. Explanations may include simple or complex processes. For example, bees may have:
- Paired elements to find an unpaired element
- Division calculations performed – even though division has not been proven before
- Count each element and then apply the even/odd sorting rule to the total count.
By teaching other animals to distinguish between odd and even numbers, and performing other abstract operations, we can learn more about how mathematics and abstract thinking form in humans.
Is mathematical discovery an inevitable consequence of intelligence? Or is math somehow connected to the human brain? Is the difference between humans and other animals less than we previously thought? Perhaps we can glean these intellectual insights, if we listen properly.
This article was originally published on Conversation by Scarlett Howard at Monash University and Adrian Dyer, Andrew Greentree, and Jair Garcia at RMIT University. Read the original text here.
https://www.inverse.com/science/honeybees-odd-even-numbers Bees and humans have a shocking skill in common, new study reveals