Grant: Discovery Launch Supplement

Social relationships are one of the most important factors shaping how a child's brain and body develops. Parents help manage their child's stress and emotional responses; a concept referred to as "social buffering". Later in childhood and adolescence, friends also play an important role in buffering stress. However, we don't yet understand the complicated physical, brain and behavioural processes involved in social buffering. It is important to understand how social buffering works, as a child's ability to regulate their stress response is critical to their psychological and brain development. This project will connect distinct lines of research on hormonal and brain responses to stress, to understand how parents and friends buffer stress. In addition, this research will include both children and adolescents, to examine how social buffering differs across development. Previous research shows that when parents or friends are with children, they can help "turn down" the child's hormonal (cortisol) stress response. In addition, parental presence can change how children's brains respond to stress (lower activity in the amygdala and stronger connections between the amygdala and prefrontal cortex [PFC]). The present study will answer several questions that have not yet been addressed by previous research. Most prior research examines: 1) either friends or parents as social buffers and does not compare the two, 2) the presence of a parent/friend rather than differences in relationship quality with parents/friends, 3) hormonal or brain processes of social buffering and does not connect the two, and 3) social buffering at one stage of development and does not investigate how social buffer might differ in children and adolescents. In this study, we plan to use a variety of research methodologies to investigate these questions. We will include both children and adolescents and measure their interactions with their parent and a close friend, and how their brains and bodies respond to stress, by using brain imaging and collecting saliva to measure stress hormones. We will assess how their relationship with their parent and a close friend (relationship quality and attachment) affects how their brain and body responds to stress. In the future, we aim to build on this project by investigating how different kinds of relationships impact social buffering in younger children, older adolescents, and adults, and with diverse research methods (other kinds of neuroimaging and biomarkers of stress). Overall, this research program will investigate the complex connections between parent and friend relationship quality, physiological stress, and brain biology, at different stages of development, with the aim of fostering child brain and emotional development.