Animal Intelligence

  Dreamer, by  R.J. Walter

Dreamer, by R.J. Walter

I’ve written about animal intelligence before, to some extent. A few weeks ago, I talked about some small cats, including the margay, which is the only known predator to use vocal mimicry to try to lure its prey closer. In one of my earliest posts, I celebrated the kea, NZ’s native alpine parrot that’s at least as smart as human 4-year-olds. And there are plenty of other species mentioned on the site that have their own unique intelligence.

But that begs the question: how do we measure animals’ intelligence? Many of our tests compare animals’ abilities against human abilities, such as testing puzzle solving abilities or self-recognition. But is this really an accurate way to study the brainpower of different animals? While humans are a pretty intelligent and adaptable species in our own way, we aren’t necessarily the gold standard for mental abilities in all contexts. What if giraffes tested our ability to strip leaves off of high tree branches? What if fish tested our ability to maintain neutral buoyancy? We’d come across as pretty stupid. How do we even define intelligence when there’s so much variation in species?

It’s a thorny problem that scientists are still trying to work out. In the meantime, though, they’re conducting lots of different types of tests that measure different aspects of the human concept of intelligence. Some of the abilities that we test for include:

This macaque recognizes itself in the mirror. Image by Ned Gong et al., via Ewen Callaway and Nature.

Generally speaking, the bigger and more wrinkly the brain, the smarter the animal is (with some notable exceptions like the octopus). Images from the National Institute of Basic Biology, Japan, and University of Washington, via Tedd Roberts and Baen..

  • Self-recognition: This is usually done with the mirror test, in which a mark (usually a bit of red paint or makeup) is applied to the subject’s face, and then they’re shown their reflection. If they touch the mark on the mirror, they don’t recognize themselves, but if they touch the mark on their own face, that indicates that they have some sense of self-identity. Humans develop their sense of self-identity around 18 months old.
  • Problem-solving: Humans are excellent at finding solutions to problems and puzzles using logic, abstract reasoning, and creativity. Solving problems in novel ways indicates high cognitive abilities and the ability of the animal to join concepts together.
  • Tool use: Many animals use various objects as tools for gathering food and other tasks, with varying degrees of creativity and success. There are also different levels of tool use – using a rock to bash open a shell doesn’t require the intelligence and finesse it would take to create a new tool by modifying something an animal found.
  • Memory and facial recognition: Memory is crucial for survival, but for some animals it goes far beyond just remembering that these berries are tasty but those other berries are poison. Social animals need to be able to distinguish individuals by sight, sound, and/or smell, and understand how to interact with each other for their best chance at survival.
  • Brain size: So far, the most reliable and robustly-tested indicator of intelligence we know of is absolute brain size – in other words, the bigger the brain, the smarter the creature. This rule doesn’t always apply; there are some very small animals that demonstrate high cognition. But it’s a pretty good overall indicator!

So considering all of these different ways of looking at intelligence, but also bearing in mind that our definition of intelligence may be limited, let’s look at some smart (to us) wild animals. 

 

Apes

It should go without saying that our closest genetic relatives are pretty similar to us in terms of intelligence. Apes and particularly chimpanzees are creative problem solvers, use a variety of tools, and famously, can learn sign language and communicate with us. Where we differ, though, is in short term memory. Chimps can memorize short number sequences and patterns in a fraction of a second, beating out humans by a wide margin. However, what we humans lack in short term memory we make up for in our unparalleled communication abilities and abstract reasoning.

 

Elephants

An elephant paints a self-portrait. Image by Deror Avi.

You’ve probably heard the phrase “An elephant never forgets.” While that’s not entirely accurate, it is true that elephants have excellent long term memories, and can recognize individuals (including other elephants and humans) even after being separated for many years. They can also recognize different human languages and tones, which helps them avoid certain groups of people that might be more likely to hunt them. They’re also internet famous for knowing how to identify bees.

 

Dolphins

Dolphins need lots of brainpower for complex social interactions.

Dolphins are pretty well known for their tricks and athletics, but their cute appearance and friendly demeanor can overshadow their smart and sometimes devious nature. Bottlenose dolphins in particular like to do things for fun, which can be innocent things like fancy flips, but sometimes includes getting “high” off of pufferfish venom, having sex (sometimes with unwilling humans) without trying to reproduce, and attacking other marine mammals without needing to for survival or territory – all in the name of entertainment.

 

Corvids

New Caledonian crows make their own custom tools from leaves and sticks. Image from Cornell University, via Brooks Hays and UPI.

Parrots may be well known for their mimicry skills, but they don’t hold a candle to corvids (crows, ravens, and jays) in terms of intelligence. Crows in particular are known for their problem-solving skills – they can solve multi-step puzzles, can make new tools out of materials they find, and even understand the concept of water displacement. They recognize individual people and have been known to exchange trinkets and favors with certain people they like. Crows also like to just have fun, as one family discovered on a snowy morning.

 

Octopuses/Octopi/Octopodes (whatever)

A tiny coconut octopus carries a nutshell and a clam shell for protection as it searches for food. Image by Nick Hobgood.

Octopuses can solve all manner of puzzles, escape from elaborate prisons (including unscrewing jar lids from the inside), use found objects as tools or shelter, and recognize faces. But the octopus is unique among intelligent animals because it’s an invertebrate with a smallish brain and a short lifespan (3-5 years). Most intelligent organisms have relatively long lives and a central nervous system with a big brain and a spine. But octopuses have neurons (brain cells) distributed throughout their entire body, including in all 8 tentacles. This allows them to maneuver and survive in constantly changing ocean ecosystems, even over just a few years. Other cephalopods like squid and cuttlefish also demonstrate high intelligence (and are so cool that they deserve their own post – coming soon!).