Imagine being on a beautiful island in the Caribbean, performing magic tricks for monkeys! Hi, I’m David from MinuteEarth, and I did just that as part of a study to understand how animal brains work. I carried a bag full of props and whenever I spotted a monkey alone, I would set up a little magic show just for them.
Here’s how it worked: I had a platform that I would hide from the monkey’s view using a piece of poster board. Then, I would take an apple from my bag and dramatically place it behind the board. I’d do this again with a second and third apple. Finally, with a grand gesture, I’d remove the board to reveal the apples to the monkey.
Most of the time, there would be three apples, but sometimes, thanks to a secret compartment, the number of apples would be different from what I showed going behind the board. When this happened, the monkeys would look surprised, which suggests they can count, at least a little bit.
Monkeys aren’t the only animals with this ability. Over the years, scientists have found that many animals, from spiders to sea lions, get surprised when the number of items they expect doesn’t match the number they see. This reaction happens when the numbers are less than four.
However, if I placed four apples and then revealed five, the monkeys didn’t seem surprised. This is true for other animals too. It seems like non-human animals might not be able to count higher than four. But that’s not entirely accurate. Monkeys do notice when four apples become six or when nine apples become twelve.
What monkeys and other animals actually do is compare the sizes of two groups of items. They notice if the group they see looks different from what they expected. If the difference is big enough, they notice it. If the difference is small, they might not.
Why do animals compare like this instead of counting exactly? Well, when there are only a few important things, like tasty apples or dangerous predators, it’s useful to notice small differences. But when there are lots of things, knowing the exact number isn’t as important. It’s more about noticing when the difference is big enough to matter, usually more than 25%.
Humans are unique because we can count specific numbers, thanks to language. Language helps us name each number, which activates a special part of our brain for complex thinking. When I performed my magic trick for adults, they were surprised even with bigger numbers. But toddlers, who can’t speak yet, reacted like the monkeys. They weren’t surprised by small differences in big numbers, but they were amazed when three apples turned into two!
To impress toddlers, I had to use something they cared about more than apples: stuffed animals.
Language isn’t the only thing that helps with math; you also need to develop your brain’s math skills. Brilliant is a great place to learn by doing, with interactive lessons in math, programming, and more. They offer courses created by professors from MIT and CalTech, helping you build skills through hands-on problem-solving.
Brilliant has launched new data courses that use real-world data to help you see trends and make informed decisions. I’m currently exploring their course on visualizing data, learning how to make sense of large datasets.
To try Brilliant for free for 30 days, visit brilliant.org/MinuteEarth or click the link in the description. You’ll also get 20% off an annual premium subscription. Thanks, Brilliant!
Recreate the magic apple trick using props like paper cups and small objects. Hide the objects behind a barrier and change the number of objects secretly. Ask your classmates to guess the number of objects and observe their reactions. Discuss how this activity relates to the counting abilities of monkeys.
Research and create a presentation on different animals and their counting abilities. Compare how various species, including monkeys, react to changes in small numbers. Present your findings to the class and discuss why these abilities might be evolutionarily beneficial.
Conduct an experiment where you show two groups of objects with varying numbers. Ask your classmates to identify which group has more objects without counting. Record the results and analyze how well they can detect relative differences, similar to how animals do.
Explore how language influences counting by learning to count in a different language. Practice counting objects in that language and discuss how naming numbers helps in understanding and remembering quantities. Reflect on how this relates to the human ability to count larger numbers.
Visit an educational platform like Brilliant and try out interactive math lessons. Focus on activities that involve counting and number comparison. Share your experience with the class and discuss how these skills can be applied in real-world situations.
This video is sponsored by Brilliant. More about them at the end of the video.
There’s an island in the Caribbean where I used to perform magic tricks for monkeys. Hi, I’m David, and this is MinuteEarth. I was working on a big study about how animal brains work, and as part of that research, I carried around a bag of props. Whenever I found a monkey hanging out by itself, I’d bring out a platform that I’d then hide from the monkey’s view with a piece of poster board. I’d take an apple out of the bag and dramatically lower it behind the poster board, then I’d take out a second apple and then a third. Finally, with a flourish, I’d remove the poster board, revealing the apples to the monkey.
Usually, there would be three apples there, but occasionally – thanks to a hidden chamber where I could stash or retrieve an apple – the number of apples on the platform wouldn’t match the number of apples I’d removed from the bag. When those mismatches happened, the monkeys would stare as if they were surprised, which suggests that they have the ability to count.
And monkeys aren’t alone. Over the past few decades, using similar experiments, researchers have found that pretty much every animal we can test – from spiders to sea lions – seems to get surprised when the number of items they expect to see doesn’t match the number of items that are revealed. At least that’s what happens when the illusion is performed with numbers smaller than four.
But if I lowered, say, four apples during the trick and revealed five apples, the monkeys didn’t seem surprised at all; nor would any other species of animal that scientists have tested. This suggests that maybe non-human animals can’t count any higher than four. But that’s not exactly right. Because while monkeys aren’t surprised when they see four apples get lowered and five get revealed, they are surprised when four apples get lowered and six are revealed, or when nine apples get lowered and twelve get revealed.
What the monkeys actually seem to be doing is comparing the relative sizes of two sets of items. One set is the amount of items they see go behind the poster board, and the other set is the amount of items they see get revealed. So if they expect there to be a pile of apples that looks one way, and instead they see a pile that looks different, that relative difference is big enough for them to notice. But if they expect a pile that looks one way and instead they see a pile that looks similar, that relative difference seems to be small enough that they don’t notice.
Why do animals do this relative comparison instead of just counting? Well, when there’s a very small amount of something important – like yummy apples or scary predators – it makes sense for an animal to be able to discern small differences between amounts. But when there are lots of things out there, knowing the exact number isn’t as important – it’s more about knowing when the amounts are different enough to matter. And “different enough” to an animal seems to be a difference greater than 25% – more or less.
Being able to specifically count numbers of things may just be a waste of energy and brainpower in most situations. Humans – with our ability to count and differentiate specific numbers – are actually the odd ones. This skill seems to be unlocked by language, which allows us to give a name to every single individual number, moving our counting ability into a special part of the brain devoted to more complicated computation.
That’s why, when I repeated my magic show with adult humans, they were surprised, even when I did the trick with bigger numbers. But when I did the show for preverbal humans – toddlers – they reacted the same way the monkeys did; they weren’t surprised by small differences between big numbers, but they were very impressed when three apples magically became two! Well, not exactly – they didn’t seem to care much about apples. I had to trick them with something they cared more about: stuffed animals.
Language isn’t everything when it comes to computation; you also have to develop that part of your brain devoted to math. And Brilliant is where you learn by doing, with thousands of interactive lessons in data analysis, math, programming, and AI. Brilliant helps you build real skills through hands-on problem-solving based on lessons created by MIT and CalTech professors.
Brilliant just launched a ton of new data courses, all of which use real-world data to train you to see trends and make better-informed decisions. I’m currently making my way through their new course on exploring data visually, where I’m learning how to parse and visualize large quantities and massive datasets to make them easier to interpret.
To try everything Brilliant has to offer for free for a full 30 days, visit brilliant.org/MinuteEarth or click on the link in the description. You’ll also get 20% off an annual premium subscription. Thanks, Brilliant.
Monkeys – Monkeys are primates that are known for their intelligence and ability to use tools. – In the study, scientists observed how monkeys used sticks to reach food that was out of their reach.
Counting – Counting is the process of determining the number of items in a group. – In psychology class, we learned how counting helps children develop their mathematical skills.
Apples – Apples are a type of fruit that can be used to study the eating habits of different species. – The researchers placed apples in the enclosure to see how the animals would interact with them.
Animals – Animals are living organisms that can move and respond to their environment. – In biology, we study how animals adapt to their habitats to survive.
Differences – Differences refer to the distinct characteristics that set one thing apart from another. – The differences between the brain structures of humans and other animals are a key focus in neuroscience.
Humans – Humans are a species of primates known for their advanced cognitive abilities and use of language. – Humans have developed complex societies and cultures due to their ability to communicate and reason.
Language – Language is a system of communication used by humans to express thoughts and emotions. – Psychologists study how language development occurs in children and how it affects their learning.
Brain – The brain is the organ in the body that controls thoughts, memory, and emotions. – Scientists are exploring how the brain processes information and how it affects behavior.
Surprised – Surprised is a feeling of shock or amazement caused by something unexpected. – The students were surprised to learn how quickly the brain can adapt to new information.
Skills – Skills are abilities that are developed through practice and learning. – Developing good study skills can help students perform better in their science classes.
