Oxytocin-Gaze Positive Loop and the Coevolution of Human-Dog Bonds

Abstract

Mutual gaze is the most fundamental manifestation of social bonding in humans between mothers and infants and between sexual partners in monogamous species. Dog-to-owner gaze probably evolved as a form of social communication during domestication with humans, leading to the establishment of a human-dog bond that is similar to a mother-infant relationship. Urinary oxytocin increases in mothers following mutual gaze in both mothers and infants. A rise in urinary oxytocin occurs in dogs following mutual gaze, but it is unclear whether the increase also occurs in dog owners.This study investigated the effect of mutual gaze in both dogs and their owners on levels of urinary oxytocin. A primary aim was to determine whether there is a causal relationship between mutual gaze and the release of oxytocin. The authors tested the hypothesis that an oxytocin-mediated positive loop (as has been postulated between mother and infants) exists between humans and dogs that is mediated by gaze. To show that the hormone was a cause not just an effect of the interaction, oxytocin was administered intranasally to dogs, and the gazing interaction between dogs and their owners as well as unfamiliar humans was assessed.Gazing behavior increased urinary oxytocin in dogs as well as their owners. Owners and dogs sharing a long mutual gaze had higher levels of oxytocin in their urine than did owners and dogs with shorter eye contact. Although a prolonged gaze increased oxytocin in dogs, it did not increase levels of oxytoxin in hand-raised pet wolves, suggesting that mutual gaze is not used in wolves as a form of social communication with humans. Female dogs receiving intranasal oxytocin gazed longer at their owners than did those given saline. Moreover, oxytocin levels were increased by intranasal oxytocin in dog owners (who had not been given this hormone). These mutual effects were not seen between dogs and unfamiliar humans or between male dogs and their owners.These findings indicate that oxytocin is the cause, not the effect, of the interaction and support of the existence of an interspecies self-perpetuating oxytocin-mediated positive loop facilitated and modulated by mutual gazing. Gazing behavior may have supported the coevolution of human-dog bonding as a common mode of communicating social attachment.

Dissecting the Role of Oxytocin in the Formation and Loss of Social Relationships

“…Recently, it was shown that OXT enables pup retrieval behavior in female mice by amplifying pup call responses in maternal auditory cortex (21). Furthermore, OXT has been implicated in maternal licking and grooming in rats (22), social affiliation of dogs toward their owners (23), and grooming of nonbond partners in chimpanzees, thus providing a cross-species mechanism that enables long-term cooperative relationships between kin and nonkin mammals (24). Notably, the OXT system not only plays a pivotal role in the formation and maintenance of pair bonds but is also affected by their disruption.…”

Bilateral enucleation in dogs: A review of owner perceptions and satisfaction

“…Facial perception, including eye gaze, plays an important role in inter-personal communication and social attachment in humans. 8,9,33,34 The ability of owners to gaze into their dog's eyes has been shown to promote the human-animal bond. 8 The hormone oxytocin regulates social bonding in humans.…”

“…Reasons may include: fear of the risks of anesthesia, post-operative aesthetics, the ability of the dog or owners to cope post-operatively, concerns of the impact on welfare and quality of life, and the impact on the human-canine bond as eye contact is a key communicative technique between owner and dog. 8,9 While it is essential to educate owners about the enucleation procedure and the reasons for performing it, it is equally important that owners have a clear expectation of the post-operative recovery and appearance of their pet. Although as veterinary surgeons we may have a positive understanding of this procedure, we often do not have the experience of an owner in a home environment.…”

Paleolithic dogs: Why sustained domestication then?

“…Thus, in presenting information on certain prehistoric specimens from the state of Idaho, Barbara Lawrence (1967: 47) referred to that trait as "this most doglike of all characters." The development of that trait may well have affected visibility (see McGreevy et al, 2004;Morey, 2010: 193), promoting the interspecific mutual gazing behaviors that are now known to characterize people and their dogs (Nagasawa et al, 2015). In any case, that trait certainly qualifies as part of Hare et al's (2012) domestication syndrome with respect to dogs.…”