A child's best friend: Behavioral, neural, and endocrinological mechanisms of longitudinal social bond formation and stress buffering effects in children and pet dogs - Project Summary The goal of this project proposal is to advance our understanding of the mechanisms that underlie longitudinal social bond development in children and their pet dogs. The strength of the social bonds that form between children and their pet dogs is thought to mediate the positive therapeutic effects of having a pet dog, yet the mechanisms involved in the longitudinal development of these social bonds are not well characterized. The overall objective of this study is to determine how social bonds between children and their pet dogs develop, and to examine the anxiolytic effects of these social bonds in order to more effectively facilitate child health and wellbeing. The specific aims of this project are 1) to assess the relationship between social bond strength, oxytocin levels, and functional responses within social reward-related brain circuits in dogs and children, and 2) to determine whether social bond strength is associated with cortisol levels and functional connectivity within stress-related brain circuits in dogs and children. These aims will be achieved by assessing changes in social bond strength between child-dog dyads across four timepoints: within one week of dog adoption, two months post-adoption, five months post-adoption, and eight months post-adoption. At each timepoint, social bond strength will be measured via a behavioral task, and salivary samples will be collected from the child and the dog at the start and end of the behavioral testing session to measure changes in hormone level throughout the session. Brain activity will be measured following behavioral testing using fMRI techniques. Through the integration of behavioral, endocrinological, and neural methodologies, we will obtain a full perspective of the longitudinal process of social bond formation in child-dog dyads that can be generalized across the broader population. The proposed study aligns with the National Institute of Child Health and Human Development’s Child Development and Behavior Branch of Human Animal Interaction’s mission of enhancing the lives of children. The results of this study will directly influence child wellbeing by allowing us to better understand the mechanisms involved in the formation of social bonds between children and pet dogs over time, which will lay the foundation for informing therapeutic outcomes in future clinical populations.