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Go to CuriosityStream.com/Psych to learn more. [ ♪ Intro ]. When we think about animal intelligence, we tend to use humans as the benchmark.

And it seems especially irresistible to make such comparisons with dogs. Even scientists do it! Like, you've probably heard that dogs are basically furry toddlers, as their cognitive abilities are on par with a 2 year old human.

But, while there are definitely some interesting comparisons to be made between the mental abilities of dogs and humans of whatever age, the minds of different species can work very differently. Comparing dogs to kids makes intuitive sense because we see our dogs as our children to some extent. That's why we call them our "fur babies" and we are their "dog parents".

And there's actually research supporting the idea that our relationships with them are very similar to the relationships we have with our kids. Like, in the presence of something new and scary, both our children and dogs will look to us for reassurance in the same way. But making a direct comparison between dogs and kids isn't really valid, or at least, we have to be extremely careful about doing it.

Still, there are experimental methods designed for preverbal children that can be applied to dogs, and they do allow researchers to learn interesting things about dogs' minds. For example, both dogs and children will look longer at something they find unexpected. And researchers have used this to show that they both have a sense of numbers.

In one experiment, dogs were shown one treat being placed behind a screen, then a second. When the screen was raised, they looked longer if they saw one or three treats, as if they were surprised, because they knew there should be two. In studies like this, dogs do tend to demonstrate cognitive abilities on par with toddlers, depending on the specific task at hand, or, at paw.

However, any claim that your dog "has the mind of" a human of any age needs to be taken with a very big, uncarriable, grain of salt. Comparisons across species are just not that simple. For one thing, equivalent performance on a task can obscure really important differences.

Some have noted that dogs and two year olds have similar vocabulary sizes, for example. And there are dogs with very large vocabularies. Chaser the border collie understands over a thousand words, for example, which is comparable to a three year old human.

But Chaser was explicitly taught those words by a psychology professor who worked with her for hours every day. This is not how kids generally learn language, it's most common for them to automatically pick up words they've been exposed to in everyday life. Also, in some cases, dogs may be able to do the same task as a child, but how they do it is subtly different.

Like, dogs can learn by observation and copying, one of the many abilities that was once thought to be exclusive to humans. And not only that, they can learn by watching and mimicking people, which is even more complex than learning by copying a member of their own species, since a dog can't imitate the actions perfectly if the action requires a body part they don't have, like fingers. But they do this copy-learning differently than kids, arguably better, in fact, because they don't blindly copy.

Children do something called overimitation: if you show them how to do a puzzle and you use an unnecessary step, they will do exactly what you did. Dogs don't. If they figure out that one step isn't needed, they'll leave it out.

And even when a dog is doing the same thing as a child, its brain may be doing something different. Scans have shown that some processes happen in the same way, like, dogs and humans both have a region of the visual cortex that activates when recognizing faces. But brain activity is markedly different in dogs when they're processing known and unknown words: dog brains show greater activation in response to the novel words, the reverse of what's seen in people.

It shouldn't be surprising that there are differences, of course, because a dog's brain isn't identical to a human's. Far more of it is devoted to smell, for example, the olfactory bulb takes up a little over 0.3% of a dog's brain, but only about 0.01% of ours. So when we're talking about animal intelligence, it's important to remember how differently species may take in and process the world.

And although we've learned a lot from using human tests on non-human animals, there are limits to what these methods can reveal. For example, something called the "mark test" can supposedly determine whether an animal is self-aware. The basic gist is that researchers put a mark on an animal's body without it knowing, and then see if, when presented with a mirror, the animal notices and examines the mark.

If they do, that indicates that they recognize the reflection is their own, something that, presumably, you can only do if you understand that there is a you. Until recently, it was thought that any animal that didn't pass this test lacked a sense of themselves as individuals, and dogs were included in that. Except, some researchers found that if you use a different method, one more appropriate for a dog, you get a different answer to that question.

Because if you let a dog smell canine urine samples, they know which is theirs, which would suggest they do have some sense of self. So yes, some types of experiments work with both dogs and children, and yes, our species do have a lot of things in common. But when you ask how intelligent an animal is, we need to be very wary of using ourselves as the measure of smartness, and think hard about whether we're asking fair questions of minds that are different from our own.

We can't really get into a dog's head to figure out what they're thinking. But we can bring them with us as we experience the world. And if you've ever seen the series “Walks with my Dog,” you know that doing that can make for some hilariously insightful television.

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