The research, which compared wolves and dogs evolution, shows that the domestication of dogs over a 33,000 year period has transformed the facial muscle anatomy of dogs specifically for facial communication with humans. And not just communication, but specifically, to elicit ‘a caregiving and nurturing response from humans’
“A muscle responsible for raising the inner eyebrow intensely is uniformly present in dogs but not in wolves,” according to the study. This high-intensity movement produced exclusively by dogs increases paedomorphism and resembles an expression humans produce when sad, so its production in dogs may trigger a nurturing response.”
The study suggests that the gaze between dogs and humans (but not wolves and humans) leads to an oxytocin feedback loop, similar to the one that exists between human mothers and infants.
Oxytocin – also known as the love chemical for its loving and nurturing qualities - has a fundamental role during the onset of maternal behaviour and mother−infant attachment and bonding.
The “mutual gaze between dogs and humans seems to trigger an increase of oxytocin in both species, which then increases the motivation to establish eye contact,” according to a different study. “As this cross-species oxytocin loop can be found in dogs and humans, but not between dogs’ closest living relative (the wolf) and humans, selection processes during domestication must have played an important role whereby dogs hijacked the human caregiving response. The most likely evolutionary scenario is that dogs’ ancestor must have, to some extent, expressed characteristics that elicited a caregiving response from humans. Humans then consciously or unconsciously favoured and therefore selected for those characteristics, leading to the analogous adaptations we see in dogs today.”
So next time your four-legged furry friend raises an eyebrow at you, remember, there’s motive. Get those doggy treats ready…