Research shows that dogs have large vocabularies and stunning social intelligence. I’ll never forget the day my daughter came home from school, looked at me sombrely, and said: ‘My teacher says you’re wrong. Dogs don’t understand us when we talk to them. They only respond to tone of voice.’ The problem with this very common view is that it has been disproven repeatedly by careful research on canine intelligence.
Dog brains contain enormous vocabularies for human words
Researchers at the Max Planck Institute for Evolutionary Anthropology in Leipzig, Germany taught a border collie named Rico the meanings of 200 words. He could even use the process of elimination to figure out unfamiliar words: if he already knew the word ‘ball’, and his trainer showed him a ball and a stick and told him to get the ‘stick’, he would bring the stick. He could even remember new words even after a month of not hearing them. Another border collie named Chaser has learned a whopping 1,022 words.
But do they really ‘know’ what those words mean? When you tell your dog to sit, and the dog sits, is this evidence that the dog knows English?
Yes, it is.
We learn the meaning of words by associating them with objects, actions, and events. Children do this when they learn their first language. Adults do this when they learn a second language. That is the part of language learning that relies on simple association.
When you tell dogs to sit and they sit, they behavior shows us that they can do three things:
- They can understand the simple concept of sitting.
- They can distinguish the word ‘sit’ from other words.
- They can connect the word ‘sit’ to the concept of sitting.
This isn’t rocket science, it isn’t magic, and it isn’t anthropomorphizing. It is just the way word learning works.
Where things get tough
You can’t learn words for things you can’t understand. So, no dog will ever learn the words ‘bacteria’, ‘economy’ or ‘atom’. Dogs may be able to hear the differences among these words, but the concepts these words represent are beyond a dog’s conceptual capacity.
Moreover, the grammatical complexity of our sentences is too hard for dogs to fully grasp. What sets human language apart from communicative systems of other species is its grammatical complexity. Our languages consist of word categories (such as nouns, verbs, adjectives, adverbs, and prepositions). We communicate different ideas by changing word order or word endings. That gives us the power to describe events from the past, or even imaginary ones that never happened. The ability to dive into grammatical complexity emerges very early in child development, beginning in the second year of life and exploding with full force in the third year of life.
No nonhuman animal to date has demonstrated the ability to construct sentences with the level of grammatical complexity typical of a three-year-old human child. Why? We have monstrously large brains which gives us extraordinary intellectual power. Our brain is seven times larger than it should be given our body size.
But it isn’t just overall intelligence that matters. Even individuals with low IQ, such as those with Down syndrome or Williams syndrome, can master the complexity of human language just fine. No, the key is the way the human brain is genetically wired for communication.
The FOXP2 gene is present in most species, from reptiles to humans. Its primary function appears to be directing neural wiring that impacts communication. About 200,000 years ago a mutation of the FOXP2 gene appeared in hominins. This genetic mutation entirely replaced more primitive versions of the gene within 500 to 1,000 human generations—a mere 10,000 to 20,000 years, which is an eyeblink in evolutionary time. The consensus among scientists is that the FOXP2 gene has been the target of heavy selection during human evolution because it changed the way our brain was wired for communication.
Dogs have the more ancient form of this gene, which means that they can’t master the grammatical complexity of human language. Their brains are smaller, which means they can’t grasp the abstract concepts that humans readily grasp. But you can expect to communicate with them about concepts that are well within their mental capacity using simple language. They can understand you when you say, ‘Sit’, ‘Bring me the small ball’, ‘No! Don’t do that’, and even ‘I love you’.
Yes, your dog does love you
When a baby is born, both mother and baby are flooded with a hormone that promotes feelings of trust and emotional bonding. This hormone, called oxytocin, is also released whenever we have contact with someone we like.
This is true not just of humans, but of dogs as well. When dogs interact with their humans, both dog and human experience a surge in oxytocin. The pleasure circuitry of the brain also becomes active on both dogs and humans when they play or cuddle. We love them, and they love us right back.
Even just the scent of their human is enough to make a dog happy. Researchers scanned dogs’ brains as they sniffed their humans’ scents, the scents of unfamiliar humans, and the scents of familiar and unfamiliar dogs. They found that the reward centers of the brain became active only when the dogs sniffed their humans’ scents. The study was published in the journal Behavioural Processes in 2015.
Dogs also feel intense compassion for human suffering. In another set of studies, researchers had people crawl inside a box and then cry out in distress as their dog sat outside the box. All dogs not only showed signs of distress, they also all opened the box to free their humans.
So, yes, your dog does understand you—and love you!
Article by Denise D. Cummins, PhD. Denise D. Cummins, PhD, is a cognitive scientist, author, and elected Fellow of the Association for Psychological Science. Her most recent book is: ‘Good Thinking: Seven Powerful Ideas That Influence the Way We Think.’
For more information visit: denisecummins.com.
