Oxytocin bonds between human and dog

Abstract

During domestication/evolution process of dogs, dogs have acquired human-like nonverbal communication skills, such as gaze and pointing following by humans, and gaze alternative behavior toward the owners. These skills, especially using eye gaze, are believed to promote the co-habituation of dogs in human society. Not only the communicative function of dog's eye-gaze with humans, it works as to form bonding between them. Eye-gaze from dogs to their owners increased urinary oxytocin, and the owner showed affiliative interactions with their dogs, which in turn, stimulate oxytocin release in dogs. Oxytocin is a hypothalamic neuropeptide stimulate maternal behavior as well as social interactions. Therefore, human and dogs can form a biological bonding via oxytocin positive loop in both sides. This type of positive loop was not observed in wolves, suggesting that dogs have acquired this function in their domestication process. Future behavioral genetic research will reveal the critical genes responsible for human-dog interaction, which would shed a light on the critical questions; "why", "how" and "when" dogs become a Man's best friend.