ECHO is a nationwide research program whose mission is to improve the health of children for generations to come. The goal is to learn how the environment affects children’s health and development, and how it interacts with genetic information. The environment includes things that children may experience throughout their lives and even before they are born, like the air they breathe, foods they eat, interactions with other people, and the neighborhoods where they live. Children ages 5-11 and a biological parent are invited to participate. The study involves one visit, with in-person and remote components, in which the child will complete a cognitive assessment and body measurements, and both the child and parent will complete questionnaires and provide bio-samples (saliva, blood, hair, and toenails).