For thousands of years we have guided the evolution of dogs to fulfill our needs for work and companionship. Service dogs are pretty remarkable. I love to watch herd dogs mimicking the dance of predator and prey. When you see a guide dog help someone navigate a building or street, you can’t help but to be impressed by the dogs “devotion” and “skill”.
It seems there is a new canine skill in the news every day. Now, in addition to the traditional roles guiding the blind and deaf, and helping the physically disabled, dogs are claimed to be able to calm autistic children, detect blood pressure changes and seizures, and find cancers. Dogs have been used in the bed bug epidemic to find the critters (with little scientific evidence of success).
Humans and dogs have co-evolved successfully to create strong owner-dog attachments (to the point of pit bull owners defending their dogs rather than acknowledging a dog’s danger to humans). It seems intuitive, and is quite plausible, that dogs can calm us, can help lead us in ways analogous to their roles in nature (if “natural” can even be applied to dogs). It’s easy to see how herding behavior can be adapted into guide dog behavior, or hunting behavior into chemical detection.
What’s less clear is whether any of these roles are based on fact rather than intuition.