Why Dogs Have Eyebrows
Over tens of thousands of years, humans have selectively bred dogs with an ability to adopt facial expressions like ours.
Facial imitation is so fundamental, so primal, that it is non-negotiable. Even if we try to consciously over-ride our automatic urge to copy other people’s expressions, we still perform tiny imperceptible movements of our own face muscles. We just cannot help ourselves. We are hard-wired to imitate facial expressions.
From birth, babies can track and copy a constant stream of micro-expressions, registering even those which last only a split second across a face. Adults are uncontrollably drawn to pulling extreme facial expressions and making strange noises in visual range of new-born babies.
"We imitate emotional expression and facial mimicry almost instantaneously, tracking the subtlest moment-to-moment changes, imperceptibly unaware of how swiftly and how completely we track the expressive behaviour and emotions of others,"
The reason we imitate faces is that we need to DO facial expressions in order to understand how others are feeling. Reading faces is not a purely mental deduction. When people are prevented from imitating facial expressions—by having their facial muscles paralysed—they are significantly less able to judge how others are feeling.
In the card game, poker, players need to read the intentions of their opponents as best they can. By the same token, they also need to hide their own intentions. Good players give no emotional or expressive cues to their opponents. They adopt a non-expressive face—a poker face. But good players are also expert at reading even the most fleeting leak of micro-expression in their opponents—what is known in the industry as a ‘tell’ but, importantly, they must imitate that leaked expression to understand what it means. A recent study established that players who kept their faces completely inexpressive, were less effective at reading the intentions of other players. An essential skill in poker is therefore the ability to hold one’s own facial expressions in check BUT, at the same time, micro-imitate the facial expressions of others.
Research confirms that we assess a person’s competence and trustworthiness from imitation of their facial expressions in just 1/10th of a second. We tend to trust these unconscious facial expressions because they and their underlying emotions are difficult to fake. Automatic imitation of each other’s facial expressions therefore provides an authentic assessment—a true reflection of how we are all feeling.
All of which brings me to dog eyebrows.
Over tens of thousands of years, humans have selectively bred dogs with an ability to adopt facial expressions like ours.
“In only 33,000 years, domestication transformed the facial muscle anatomy of dogs specifically for facial communication with humans,”
Eyebrows are very expressive. Although the ancestor of domestic dogs, the wolf, has no eyebrows, we have bred dogs which have expressive eyebrows. Of course, eyebrows are not the only indication of emotion, but they are extremely easy to imitate. This selection for canine eyebrows may provide us with more than the mere impression that dogs are sharing our emotions. Just as we read their facial expressions through imitation, so our canine companions can feel how we are feeling through automatic imitation of our expressions.
Studies show that dogs infer how we are feeling and therefore what we are intending to do from a combination of facial expressions, voice, and body language. Being ‘pack’ animals, they are hardwired to read the intentions of others. They do this the same way we do. They imperceptibly imitate our facial expressions and thereby feel how we feel.
For more details see book, Another Self: how your body helps you understand others. (UK book, US book)