Are animals smart? From dolphin language to toolmaking crows, lots of species have obvious intelligence

Curious Kids^[1] is a series for children of all ages. If you have a question you’d like an expert to answer, send it to curiouskidsus@theconversation.com^[2]. Are animals smart? – Deron It’s a fascinating question that intrigues millions of pet owners, animal lovers, veterinarians and scientists all over the world: Just how smart are animals? Scientists once believed a brain with billions of neurons was a requirement for intelligence. After all, that’s why you’re able to think – neurons are the nerve cells in the brain that connect and transmit messages to each other^[3]. For the record, the human brain has about 86 billion neurons^[4]. For comparison, dogs and cats have less than one billion^[5]. Yet the more that scientists like me^[6] study animal emotion and cognition^[7] – the ability to learn through experiences and thinking – the more we find that humans are not very special at all. Many nonhuman species can do these things too. Right now, there’s no agreement on how to decide whether a particular animal species is intelligent. But most scientists who study animal cognition have observed that many animals are able to solve problems, use tools, recall important information about their environment and recognize themselves in the mirror. Measuring an animal’s intelligence is harder than you might think.Toolmaking bears and crows Memory is a marker of intelligence. Of all animals, humans possess the most accurate and sophisticated memory^[8]. But elephants can recognize as many as 30 traveling companions at a time^[9]. They also learn to migrate away from drought-prone areas, based on memories of earlier droughts^[10]. That kind of recall – known as episodic memory^[11] – is the ability to remember an event, including when and where it occurred. Until recently, scientists thought only humans had it. But now researchers have learned that some birds, cats, rats, monkeys and dolphins have it too.

Animals may not remember every experience – neither do people – but they do recall things critical to their survival. For example, birds know where they stored food^[13]. Monkeys know the presence of a predator^[14].

Scientists once thought tool use was an exclusively human ability, but that’s not so. Chimpanzees use sticks to catch termites^[15] and stones to crack nuts open^[16]. Crows can even manufacture tools^[17]. By bending a wire, they can make a hook to retrieve a food reward that’s otherwise out of reach.

Researchers presented eight captive brown bears with this food challenge^[18]: Three objects – a large log, a small log and a box – were placed in an outdoor enclosure. A food reward was suspended above them. Six of the eight bears were able to move the logs and box into positions that enabled them to fetch the reward. Essentially, they used the three objects as tools.

Dolphin, chimpanzee communication

Language is another measure of intelligence. People, of course, have enormously sophisticated communication skills. But dolphins have complex dialects^[19] in the form of crackles, squeaks and whistles. Many researchers say the noises are a language^[20]. Chimpanzees and gorillas have used sign language to express emotions and ask for things^[21] from people.

Self-awareness – the ability to recognize yourself as an individual – signals intelligence. Babies don’t recognize themselves in the mirror until they are about a year and a half old^[22]. Up until then, they probably think the mirror image they see is another baby.

Many other species, including dolphins, ravens and elephants, recognize themselves in the mirror. Researchers put a red dye mark on chimpanzees under anesthesia; once awake, the chimps saw their reflection in a mirror. Instead of touching the red mark on their reflection in the glass, they touched the red mark on themselves^[23], indicating self-recognition.

Just because animals can’t do certain things, it doesn’t mean they’re unintelligent. After all, humans can’t fly like a bird or swim like a fish. Nor is there a need for us to have the incredible sense of smell a dog has^[24]. We’d be sniffing hundreds of different smells from miles away – the scents from perfumes and pollution, gardens and garbage. From an evolutionary standpoint, that wouldn’t help us much. Plus, we’d get sick of it very quickly.

But all animals, including humans, have developed a wide range of capabilities so they can succeed in the environment they live in. Put simply, we’re all using our brains. Now that’s intelligent.

Hello, curious kids! Do you have a question you’d like an expert to answer? Ask an adult to send your question to CuriousKidsUS@theconversation.com^[25]. Please tell us your name, age and the city where you live.

And since curiosity has no age limit – adults, let us know what you’re wondering, too. We won’t be able to answer every question, but we will do our best.

References

1. ^{^} Curious Kids (theconversation.com)
2. ^{^} curiouskidsus@theconversation.com (theconversation.com)
3. ^{^} transmit messages to each other (kids.nationalgeographic.com)
4. ^{^} 86 billion neurons (www.nature.com)
5. ^{^} less than one billion (www.pbs.org)
6. ^{^} scientists like me (experts.okstate.edu)
7. ^{^} cognition (www.verywellmind.com)
8. ^{^} most accurate and sophisticated memory (www.su.se)
9. ^{^} 30 traveling companions at a time (www.scientificamerican.com)
10. ^{^} memories of earlier droughts (www.sciencedaily.com)
11. ^{^} episodic memory (cambridgeblog.org)
12. ^{^} Santiago Urquijo/Moment via Getty Images (www.gettyimages.com)
13. ^{^} where they stored food (www.newyorker.com)
14. ^{^} presence of a predator (phys.org)
15. ^{^} sticks to catch termites (news.ucsc.edu)
16. ^{^} stones to crack nuts open (janegoodall.ca)
17. ^{^} manufacture tools (doi.org)
18. ^{^} with this food challenge (doi.org)
19. ^{^} have complex dialects (dolphins.org)
20. ^{^} noises are a language (kids.nationalgeographic.com)
21. ^{^} express emotions and ask for things (www.koko.org)
22. ^{^} about a year and a half old (cns.utexas.edu)
23. ^{^} touched the red mark on themselves (doi.org)
24. ^{^} incredible sense of smell a dog has (www.rover.com)
25. ^{^} CuriousKidsUS@theconversation.com (theconversation.com)