Humans and their unconditional love for dogs

1. Dogs can maintain eye-to-eye contact, and we love that
2. The secret is in their eyebrows
3. Dogs have social skills similar to a toddler
4. Dogs can show empathy
5. References

You are sitting at your breakfast table, busy munching on your toast, and you hear a loud playful bark from behind you. It’s your furry little golden retriever puppy who has just sensed that something yummy is being served. He comes running, kneels beside your chair, looks directly into your eyes with his brown, puppy eyes and makes that - ‘I am hungry’ expression. You are trying to be firm about not pampering your dog with excessive treats, but who can resist a pup and its cute little tantrums, right? So you cave, obviously, and give him a piece of your toast. He immediately thanks you by jumping up and down, wagging his tail and licking you all over. He is happy, and you are happy that you made him happy - it’s a win-win situation (Who cares about discipline anyway).

It’s no surprise that we humans love our dogs. Not just in recent times, with whole Instagram accounts beings dedicated to pet dogs, but for centuries on end. One of the earliest evidence for this comes from Natufian in Northern Israel. This site is famous for the skeletal remains of a human and a puppy buried together, from almost 12,000 years ago (DAVIS and VALLA, 2005). Such ancient remains have also been found in many other parts of the world, like Central Russia and Germany (Verginelli et al., 2005). This essentially indicates that humans and dogs may have shared a very close relationship with each other for thousands of years.

But why do we share such a unique relationship with dogs? Research points to several exciting reasons.

Dogs can maintain eye-to-eye contact, and we love that

Ever noticed how your dog stares right into your eyes, as though he is looking directly into your soul? This kind of ‘gazing’ behaviour is known to be a very important part of developing social attachment. It forms the basis for the early bonding between a mother and her offspring, and also between two sexual partners. This is because mutual gaze has been shown to release oxytocin - the love hormone, which helps maintain a strong bond between two individuals.

A group of researchers, therefore, wanted to see if something similar happened in the case of dogs and humans (Nagasawa et al., 2015). They examined this gazing behaviour in a 30-minute interaction between dogs and their owners. Interestingly, they observed that a dog’s gaze increased the amount of oxytocin in the owner. This in turn increased the amount of interaction the owner had with their dog - in the form of touching or talking to the dog. The study essentially shows that a dog’s gaze can develop a bond similar to that between a mother and her offspring.

The secret is in their eyebrows

Genetic analysis of wolf and dog DNA shows that dogs evolved from wolves and may have been domesticated over 33,000 years ago. It is hypothesised that dogs may have undergone a process of ‘self-domestication’ as they began scavenging food from human agricultural settlements. During this process of domestication, dogs began to evolve facial features that would help them better communicate with humans. One such feature is the evolution of a unique muscle - levator anguli oculi, which helps lift their inner eyebrow with great intensity (Kaminski et al., 2019). Ever observed your dog looking at you with one eyebrow raised, as though he had an urgent question to ask you? - That is the levator anguli oculi in action.

So what does raising an eyebrow do? It basically makes the eyes of the dog look bigger, giving it a more puppy-like or infant-like appearance - something called paedomorphism. And don’t all humans just love to cuddle babies and puppies? This eyebrow lift also happens to resemble the expression of when humans are sad, making us feel somewhat loving and caring towards these brilliant animals. In fact, a study also shows that dogs which made a high frequency of these eyebrow-lifting movements were more likely to get adopted from rehoming centres (Waller et al., 2013). Now isn’t that an incredible feat of evolution!

Dogs have social skills similar to a toddler

When playing fetch with your dog, you may have often used ‘pointing gestures’ to indicate to your dog where the object is. Most often, your dog can follow your instructions. This is an example of cooperative communication, where the dog is able to understand your needs or instructions. Cooperative communication is a social skill unique to very few animals, one among them being humans.

Interestingly, dogs seem to exhibit similar cooperative communication skills.

As a matter of fact, a study that tested over 300 Golden Retrievers for their ability to follow pointing gestures, showed that dogs actually had social skills similar to human babies. This is quite extraordinary considering that human babies have far superior social skills even when compared to our closest relatives - the great apes! Additionally, they found that dogs passed on these skills from one generation to another. This means that dogs most likely evolved these skills during domestication, helping them better communicate with humans (Bray et al., 2021).

Dogs can show empathy

Many dog owners report that their dogs can celebrate their joys and grieve their sorrows. A study that looked into the interaction between a dog and a stranger, showed that dogs tended to interact more with the stranger when the stranger was pretending to be crying. They seemed to show empathetic behaviour towards the stranger by licking and sniffing, and didn’t show the same behaviour when the stranger was casually humming or talking (Custance and Mayer, 2012). This indeed explains why having a dog might be such a joyful and fulfilling experience for many.

Humans and dogs are perfect examples of two organisms co-evolving with each other, achieving near-perfect compatibility. The survival of dogs as a species has indeed been hugely enhanced by the food, shelter and care provided by humans. However, it goes without saying that humans too have greatly benefited from dogs. Studies show that dogs can enhance our overall mental health, preventing burnout and stress. They might especially be helpful in mentally challenging times (Merkouri et al., 2022). It is then not so surprising that dogs have gone from being mere pets to vital members of families in many households.

References

1. S. DAVIS and F. VALLA, Evidence for domestication of the dog 12,000 years ago in the Natufian of Israel. Nature. 276, 608-610 (2005). 10.1038/276608a0. context
2. F. Verginelli et al., Mitochondrial DNA from Prehistoric Canids Highlights Relationships Between Dogs and South-East European Wolves. Molecular Biology and Evolution. 22, 2541-2551 (2005). 10.1093/molbev/msi248. context
3. M. Nagasawa et al., Oxytocin-gaze positive loop and the coevolution of human-dog bonds. Science. 348, 333-336 (2015). 10.1126/science.1261022. context
4. J. Kaminski et al., Evolution of facial muscle anatomy in dogs. Proceedings of the National Academy of Sciences. 116, 14677-14681 (2019). 10.1073/pnas.1820653116. context
5. B. Waller et al., Paedomorphic Facial Expressions Give Dogs a Selective Advantage. PLoS ONE. 8, e82686 (2013). 10.1371/journal.pone.0082686. context
6. E. Bray et al., Early-emerging and highly heritable sensitivity to human communication in dogs. Current Biology. 31, 3132-3136.e5 (2021). 10.1016/j.cub.2021.04.055. context
7. D. Custance and J. Mayer, Empathic-like responding by domestic dogs (Canis familiaris) to distress in humans: an exploratory study. Animal Cognition. 15, 851-859 (2012). 10.1007/s10071-012-0510-1. context
8. A. Merkouri et al., Dogs and the Good Life: A Cross-Sectional Study of the Association Between the Dog–Owner Relationship and Owner Mental Wellbeing. Frontiers in Psychology. 13, (2022). 10.3389/fpsyg.2022.903647. context