My son is lobbying hard for a dog. He's been doing this for years and we compromised last year by getting him two kittens. He likes them but insists they aren't nearly as responsive or smart as a dog. They don't respond to their names and they only seem to know two words: snack and eat (and yes, those are practically the same thing, so you can see where their priorities lie). Turns out, my son may be onto something. There are so many signs your dog understands you in ways that other animals just don't.
Dogs can be very responsive to verbal cues and to non-verbal ones. They sense emotion and interact with their owners accordingly. As my son says, "when they look into your eyes, they see your soul." It does feel like that sometimes. When your dog cock their heads toward you, it truly feels like they are listening, and when they actually do what you ask it's like a small miracle because you don't expect an animal, particularly one that furry and cute, to understand the human language. In fact, it may seem like you're dealing with a toddler, and that's probably because dogs have the intelligence level of a young child. "A 2011 study published in 'Learning & Behavior' found that domestic dogs are roughly as intelligent as a 2-year-old human. That means that they are capable of understanding the meaning of roughly 165 words and that they can make sense of body language," reported Dog Notebook.
If you are spending quality time with a dog these days, it's probably obvious to you that your dog understands you, but here's how to know for sure.
They know their name
On this one, you need to distinguish between turning around when they hear your voice and responding specifically to their own names. Wag! says that sometimes it can appear that they are responding to their name, but they really are only reacting to their owner's tone of voice. The ways to tell if they truly know their name are if they come from another room when you call, or if they react by perking up or looking in your direction when you mention their name in conversation with someone else. Wag! suggests you try using the same tone of voice with different names and if they respond to their name and not others, then it's likely they can distinguish their moniker from other words.
They do what they are told
This goes beyond simple commands like "sit" and "stay." When you are able to say, "go over to Matt" or "get your bone" and they do it, you know you're talking about a greater comprehension. John Pilley, a retired psychology professor at Wofford College in South Carolina, and author of the book, Chaser: Unlocking the Genius of the Dog Who Knows a Thousand Words, trained his dog over five years to learn more than 1000 words, including grammar.
They get jealous
Just like kids will compete for a parent's attention, dogs are also keenly aware of their status in the house. Two researchers from the University of California San Diego found that dogs got anxious and distressed when their owner was giving another pet more attention. This is helpful to know in case you want to prepare your dog for a new baby.
They become protective
Dogs can keenly sense danger and may growl at a stranger or someone who isn't treating you right. This could be because, as The Dodo said, dogs are highly sensitive to pheromone changes and subtle facial expressions.
They follow where you point
Dogs are one of, if not the only, animal who can take direction from a finger. Patricia B. McConnell, Ph.D. and Certified Applied Animal Behaviorist, wrote that puppies can follow the direction of the pointing arm (while most chimpanzees and wolves can not), and that this may be so because they are predisposed to be able to follow when a human points to an object or direction. So when you tell your dog to go to their dog bed in the corner of the room it could be because they understand the sentence, or because they are actually following the direction of your finger.