Pet and working dogs raised with humans are known to form attachments to their caregivers and other humans with whom they have a stable relationship. Attachment style varies across dog-human dyads, with securely attached dogs exhibiting the secure base effect, an ability to find comfort in the presence of an attachment figure in unusual situations, allowing for greater exploration. The secure base effect is also known to facilitate interactions with unfamiliar individuals. Dogs who engage in Animal Assisted Activities (AAA) are often asked to engage with unfamiliar people in unfamiliar environments, therefore it is possible that dogs with a secure attachment to their human handlers may be more prepared for success in this role. This study evaluated the behavior of 16 dogs who engage in AAA. Using a secure base test dogs were categorized as demonstrating secure (exhibiting the secure base effect with their owner/handler; n = 8) or insecure (not exhibiting the secure base effect; n = 8) attachment styles toward their handlers. Later the dyads participated in a mock animal assisted activity session to evaluate their working behavior. Our findings indicate that independent of attachment style, dogs who engage in AAA spent significantly more time in proximity to, and touching, the AAA participant than their handler (p < 0.001 for both proximity and touch). However, on average the AAA dogs spent significantly more time gazing at their handler than at the participant during the session (p = 0.03). Dogs with an insecure attachment style appear to have driven this effect as evidenced by a non-significant trend suggesting that they gazed longer at their handlers than at the participant (p = 0.07), whereas secure dogs did not display the same trend (p = 0.24). This could suggest that while their training mandates proximity and interaction with unfamiliar people, dogs who engage in AAA may be using gaze to maintain contact with their handlers, especially in the absence of a secure attachment where prolonged comfort seeking from the attachment figure would be expected.

Highlights

Although considerable progress has been made in understanding the genetic basis of morphologic traits (for example, body size and coat color) in dogs and wolves, the genetic basis of their behavioral divergence is poorly understood. An integrative approach using both behavioral and genetic data is required to understand the molecular underpinnings of the various behavioral characteristics associated with domestication. We analyze a 5-Mb genomic region on chromosome 6 previously found to be under positive selection in domestic dog breeds. Deletion of this region in humans is linked to Williams-Beuren syndrome (WBS), a multisystem congenital disorder characterized by hypersocial behavior. We associate quantitative data on behavioral phenotypes symptomatic of WBS in humans with structural changes in the WBS locus in dogs. We find that hypersociability, a central feature of WBS, is also a core element of domestication that distinguishes dogs from wolves. We provide evidence that structural variants in GTF2I and GTF2IRD1, genes previously implicated in the behavioral phenotype of patients with WBS and contained within the WBS locus, contribute to extreme sociability in dogs. This finding suggests that there are commonalities in the genetic architecture of WBS and canine tameness and that directional selection may have targeted a unique set of linked behavioral genes of large phenotypic effect, allowing for rapid behavioral divergence of dogs and wolves, facilitating coexistence with humans.

Past research has suggested that a variety of factors, phylogenetic and ontogenetic, play a role in how canines behave during problem-solving tasks and the degree to which the presence of a human influences their problem-solving behaviour. While comparisons between socialized wolves and domestic dogs have commonly been used to tease apart these predictive factors, in many cases a single dog population, often pets, have been used for these comparisons. Less is understood about how different populations of dogs may behave when compared with wolves, or with each other, during an independent problem-solving task. This experiment compared the independent persistence of four populations of canines (two groups of pet domestic dogs, a group of free-ranging domestic dogs, and human-socialized wolves) on an independent problem-solving task in the presence of an on looking human. Results showed that wolves persisted the most at the task while free-ranging dogs persisted the least. Free-ranging dogs gazed at the human experimenter for the longest durations during the task. While further research is needed to understand why these differences exist, this study demonstrates that dogs, even those living outside human homes as scavengers, show comparatively low levels of persistence when confronted with a solvable task in the presence of a human as well as significantly greater duration of human-directed gaze when compared with wolves.

Reports of variability in the social behavior of the domestic dog (Canis lupus familiaris) are common across populations, breeds, and individuals. This has often been considered a challenge for characterizing the nature and origins of the domestic dog’s social cognition. Here, we propose that this variability might be explained by social plasticity, a trait that could contribute to the success of the domestic dog and facilitate the dog-human bond. Additional research specifically aimed at investigating population and individual variation in canine social behavior, such as attachment-style research, may provide important insight into domestic dogs’ biological success, as well as knowledge that could benefit both dogs and humans in a wide range of applied settings.