Quantitative Behavioral Analysis and Qualitative Classification of Attachment Styles in Domestic Dogs: Are Dogs with a Secure and an Insecure-Avoidant Attachment Different?

SIMPLE SUMMARY: Previous limited literature suggest that dogs present the same attachment styles as those observed in children towards their caregivers, namely secure, insecure-avoidant, insecure-ambivalent, and disorganized. However, such classification for dogs has never been corroborated by the simultaneous analysis of quantitative measures of behavior recorded during the Strange Situation Procedure (SSP). Since several modified SSPs have been used to investigate dog-to-owner attachment, in this study, two different groups of dog-owner dyads underwent two different versions of the SSP. Dogs were classified based on their attachment pattern toward the owner. For this purpose, we developed a new adaptation of the classification used for human infants. In addition, dogs’ behavior was recorded throughout the test. Behavioral differences between dogs classified as secure and avoidant were investigated. Results suggest that the classification used was effective at identifying secure and avoidant attachment styles in dogs. Like in children, behavioral differences between secure and avoidant dogs were particularly evident as the test progressed. While secure dogs showed an increase in proximity/contact seeking behaviors toward their owners, avoidant dogs did not. Larger samples may be needed in future studies to support these findings and to be able to include also ambivalent and disorganized dogs. ABSTRACT: Since several modified Strange Situation Procedures (SSP) have been used to investigate dog-to-owner attachment, in this study two different samples of dog-owner dyads underwent two modified versions of the SSP. Dogs’ attachment style to the owner was assessed based on a novel adaptation of the attachment pattern classification used for infant-caregivers. Dogs’ behavioral data were collected using continuous sampling and, in the second protocol, also with a scoring system for greeting and social play. In both studies, secure and avoidant dogs’ behavior was compared using the Mann Whitney test, while differences within each group across episodes were analyzed using the Wilcoxon paired sample test. The classification seemed to be effective at identifying both avoidant and secure attachment patterns in dogs. As expected, differences in key attachment behaviors, such as proximity/contact seeking toward the caregiver, between secure and avoidant dogs were more evident in the final episodes of the test. Differently from secure dogs, avoidant dogs did not show an increase in proximity/contact seeking behavior with the caregiver in any of the procedures. Further studies with larger samples are needed to support the effectiveness of this classification and investigate on the remaining attachment styles.