Trajectories of sibling relationship quality: understanding the genetic and environmental mechanisms and associations with childhood mental and physical health

The National Institute of Child Health and Human Development awarded Arizona State University $100,228 on December 1, 2026, under the Child Health and Human Development Extramural Research program (CFDA 93.865) to fund longitudinal research examining sibling relationship trajectories and their association with childhood mental and physical health outcomes.

The research uses data from the Arizona Twin Project, an ongoing longitudinal study of twins and their families in Arizona with a racially and socioeconomically diverse sample. The study employs latent growth mixture modeling to examine sibling relationship quality—specifically sibling warmth and conflict—measured at ages eight, nine, ten, eleven, and thirteen years. The research investigates genetic and environmental contributions to sibling relationship quality and analyzes associations between sibling relationship trajectories and childhood internalizing symptoms, externalizing symptoms, and chronic pain. The work addresses a gap in psychological literature by combining longitudinal, genetically-informed, and integrated physical-mental health approaches to understand how warm sibling relationships may protect children's wellness and inform prevention of mental and physical health challenges.

The award is a Project Grant with a period of performance from December 1, 2026, through June 30, 2028. Work is performed in Tempe, Arizona. Arizona State University's Office of Research and Sponsored Projects Administration serves as the administrative entity for the award.

Abstract

Instances of childhood internalizing, externalizing, and chronic pain symptoms are common and increasing in prevalence. As rates increase, so does the urgency of finding developmentally appropriate ways to address these concerns. Sibling relationships are a prime candidate to consider because of their relevancy in childhood and because existing literature highlights the protective nature of warm sibling relationships for children's physical and mental health. Sibling relationships have also traditionally been understudied in psychological literature, so there is a clear need for research which broadens this field to more complex longitudinal research and genetically-informed research. There is also a need for more research which combines physical and mental health to gain a comprehensive understanding of child wellness. The proposed study is innovative in that IT will be novel in examining sibling relationship trajectories in childhood using latent growth mixture modeling, exploring genetic and environmental contributions to sibling relationship quality longitudinally, and investigating the association between sibling relationship quality trajectories and child internalizing, externalizing, and chronic pain symptoms. Overall, the proposed study will provide important and developmentally relevant information needed to prevent mental and physical challenges in children. The proposed research will use data from the arizona twin project, an ongoing longitudinal study of twins and their families in the state of arizona. The sample is diverse in race and socioeconomic status and allows for the assessment of sibling relationship quality (i.e. sibling warmth and conflict) at eight years, nine years, 10 years, 11 years, and 13 years, and the assessment of internalizing, externalizing, and chronic pain symptoms at 13 years. My training plan is designed to build expertise in advanced statistical techniques, such as latent growth mixture modeling and genetically-informed research methodologies, to examine sibling relationship trajectories and their association with childhood internalizing, externalizing, and chronic pain symptoms. Under the guidance of my specialized team of mentors, I will expand my strong background in family dynamics to understand the associations with childhood mental and physical health, positioning me to make significant contributions to research and interventions that address these interconnected areas.