The Human-Dog Relationship – Science of the Special Bond
Human and dog, a divine pairing. Two species that have been companions since ancient times, for at least 35,000 years, some say. Wolves became our allies, or perhaps we drew them close to us. No matter the beginning, it profoundly impacted both of our lives.Let's delve into the science and take a closer look at the non-verbal communication and deep understanding between dogs and humans. It begins with glances and ends with heartbeats.
Shattering myths about dogs and eye contact
In the past, it was said that one should not look dogs in the eyes, only if the intention was to dominate them. It was believed that dogs perceived it as a threat. It was also thought that dogs who stared at us for a long time were attempting to climb the ranks. Eye contact was seen as a challenge to the chain of commands. Training methods advocated back then (and unfortunately, to some extent today) involved "staring down" the dog until she/he looked away. Thankfully, we know better now. Much better.
Unique eye contact between dog and human
Modern research has debunked the old myths and provided exciting facts about dogs' eye contact, facial expressions, and emotional connection to us. It turns out that dogs enjoy looking at us when they feel secure and want to get to know us, interact with us, convey something, but also when they want to find out how we are doing and what we feel. This is unique. Dogs don't do the same thing with each other or other animals. And it's not something other animal species do to the same extent as dogs do with us.
How dogs interpret our facial expressions
When dogs look at us, they read us. In an ethological study, images of human faces with different emotional expressions were shown to dogs. The results were astounding. The dogs studied the facial expressions very carefully. When the videos of the dogs were analyzed, it was also observed that they studied the right half of the face more intensely than the left. Humans show emotions more clearly with their right facial half. After thousands of years by our side, dogs have learned to direct their gaze there. Again, this applies only to us. Dogs don't glance at the right facial half when studying each other or other animals.
Dogs and our honest eyes
For dogs, there might have been historical survival value in being able to interpret our emotions, and surely, it facilitates our coexistence today. One focal point dogs have when studying us is our eyes. Experts studying human facial expressions and eyes have observed that we don't have much control over the emotional expressions that happen in our eyes. Our eyes are, therefore, very honest.If we like something, our pupils enlarge; if we experience something unpleasant, they contract. When our eyes shine, we are happy and well. One doesn't need to see a person smiling to understand that they are doing so. A steady gaze indicates focus. If the eyes turn dark and narrow or widen, it suggests anger. If we feel unsure, our gaze becomes unfocused. And when we grieve, our gaze loses its luster. Dogs can see and interpret this non-verbal language.
Dog communication through eyes and facial expressions
Another study also shows that dogs communicate with us in the same way they perceive we communicate with them – through facial expressions and glances. Dogs exhibit more facial expressions and eye contact when interacting with us than with each other or other animals.Dogs that were filmed receiving attention from a human and then having their backs turned on the human showed a marked change in facial expression. Their gaze first sought the person while they themselves exhibited a more expressive face. When the person then turned their back to the dogs, their facial expressions smoothed out and looked more unaffected; they stopped communicating.
Emotional connection between dog and human
Other exciting research has shown that dogs and humans emotionally infect each other. In psychology, this is called "emotional contagion," meaning a person's emotional state can be transferred to another person through non-verbal communication. This is well-known among humans, but it also happens between dogs and humans! Other studies have shown that dogs' heart rate variability increases (they become anxious) when they perceive their owner to be anxious, stressed, or sad. The researchers put owners in distress, confined in a glass room where their dog could see them. Then they called for help. The majority of the dogs showed distress when their owner showed the same emotion. And many of the dogs solved the situation by pushing the door open and rescuing their human from the predicament. Isn't that beautiful?
Synchronized heartbeats: A sign of sociability
And we are not finished with the subject yet. An Australian study, conducted on three dogs and their humans, yielded fascinating results. The dogs and humans were equipped with heart rate monitors. First, they were separated from each other, and then they were reunited. Within a minute after the reunion, it was observed that both the dogs' and their humans' heart rates decreased (they had increased during the separation). Remarkably, the heart rhythms, which had become more irregular during separation (indicating stress/anxiety), appeared to mirror each other after the reunion. When the curves were superimposed, they became one. Their hearts beat in sync and aligned!
Co-evolution: Evidence of dog and human interaction
All this fantastic data is evidence of something beautiful – the coevolution of dogs and humans! Our time together has shaped both of us. We have developed behaviors, physiological reactions, and abilities that benefit our relationship and cooperation. Isn't science lovely!
Exciting research findings
Babies understand dog language
A psychological study showed that human toddlers could match pictures of dogs expressing different emotions with dog sounds expressing the same feeling. An angry growl and threatening bark led the child to choose pictures of angry dogs, while a friendly yelp led the child to choose images of a happy dog. Phenomenal!
People's natural understanding of dogs
Another study showed that people, without any prior knowledge, can interpret dogs' behaviors and emotional expressions. The study was conducted on people of different age groups. Children under eight years of age scored slightly lower when it came to interpreting dogs' expressions of fear.
Dogs' synchronization with humans
Another study shows that dogs synchronize their behavior with their human companions, both children and adults. They move when we move, they drink when we drink, they lay down when we do or when they expect it, they accelerate when we do, and so on. This form of synchronization occurred more frequently in dogs that had lived with their humans since puppyhood. Rehomed dogs also exhibited synchronization but not to the same extent.
The role of oxytocin in dog and human bonding
Research shows that when dogs make eye contact with us, the hormone oxytocin, which induces calm and relaxation, is released, contributing to increased attachment and feelings of togetherness. This strengthens our bonds and sense of belonging. This doesn't happen between wolves and humans, even if the wolves in the study were raised by humans. This biochemical feedback loop is deeply rooted and likely has its origins in our coevolution with dogs and the domestication process. For a deeper understanding, please read about Oxytocin: crucial for the dog-human relationship.
The dog's smile: a unique gesture towards us
Some dogs "smile," pulling back their lips and showing their front teeth while the rest of their body signals happiness. And guess what, they only do this to us! Not to each other or other animals. It may be a way for them to imitate our smiles. Remarkable!
Dogs' melodic communication with humans
Have you ever met a dog that talks? Not barking, howling, or whining, but mumbling and producing melodic sounds. Doesn't it sound very similar to how we speak? This is something dogs only do in interaction with us, often during eye contact. An intriguing study would be to examine if this "speech" and melodies differ in different countries or regions. In that case, the results could suggest that dogs have adapted their vocalizations based on the dialect or languages they've experienced. That would be fascinating!
Written by: Caroline Alupo
Caroline Alupo is Petli's co-founder. She has a master's degree in ethology and is also a trained dog trainer and dog psychologist. She has 19 years of experience as a professional dog trainer. Read more about Caroline here.
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