I’ve read dog articles by Stanley Coren but never seen that graph. So interesting. How do we know a dog’s development doesn’t include more complex emotions? It‘s easy for me to think she experiences complex emotions because she really is very smart. She understands some words in 3 languages.
Not at all discounting her intelligence, but there are different kinds of intelligence. I haven't looked further to see if certain types of intelligence might be more closely associated with more complex emotions, or if we're looking at systems that are more separate.
From that same article, the determination is based on similar brain structure, chemistry, hormones...
What We Know about Dog Emotions Now
Science has clearly progressed a long, long way beyond the thinking of Descartes and Malebranche. We have now come to understand that dogs possess all of the same brain structures that produce emotions in humans. Dogs have the same hormones and undergo the same chemical changes that humans do during emotional states. Dogs even have the hormone oxytocin, which, in humans, is involved with feeling love and affection for others.
With the same neurology and chemistry that people have, it seems reasonable to suggest that dogs also have emotions that are similar to ours. However, it is important to not go overboard and immediately assume that the emotional ranges of dogs and humans are the same.
Current studies of Dog Emotions
To understand what dogs feel, we must turn to research done to explore the emotions of humans. It is the case that not all people have the full range of all possible emotions, and, in fact, at some points in your life you did not have the full complement of emotions that you feel and express today. There is much research to demonstrate that infants and very young children have a more limited range of emotions. It is over time that the infant’s emotions begin to differentiate and develop and, by the time they’ve reached adulthood, their range of emotional experiences is quite broad.
Why is such data important to understanding emotional lives of our dogs? Researchers have now come to believe that the mind of a dog is roughly equivalent to that of a human who is two to two-and-a-half years old. This conclusion holds for most mental abilities as well as emotions. Thus, we can look to the human research to see what we might expect of our dogs. Just like a two-year-old child, our dogs clearly have emotions, but many fewer kinds of emotions than found in adult humans.
At birth, a human infant only has an emotion that we might call excitement. This indicates how excited he is, ranging from very calm up to a state of frenzy. Within the first weeks of life the excitement state comes to take on a varying positive or a negative flavour, so we can now detect the general emotions of contentment and distress. In the next couple of months, disgust, fear, and anger become detectable in the infant. Joy often does not appear until the infant is nearly six months of age and it is followed by the emergence of shyness or suspicion. True affection, the sort that it makes sense to use the label “love” for, does not fully emerge until nine or ten months of age.
The complex social emotions—those which have elements that must be learned—don’t appear until much later. Shame and pride take nearly three years to appear, while guilt appears around six months after that. A child is nearly four years of age before she feels contempt.
The Emotions that Dogs Actually Experience
This developmental sequence is the golden key to understanding the emotions of dogs. Dogs go through their developmental stages much more quickly than humans do and have all of the emotional range that they will ever achieve by the time they are four to six months of age (depending on the rate of maturation in their breed).
The important fact is that we know that the assortment of emotions available to the dog will not exceed that which is available to a human who is two to two-and-a-half years old. This means that a dog will have all of the basic emotions: joy, fear, anger, disgust, and, yes, love, but the dog does not experience the more complex emotions like guilt, pride, and shame.
