Early Years and Families Published: January 1, 2016 Socio-demographic Profile 0-5 and Parents: Province of Québec Early child development (ECD) is a cornerstone of human development and childhood is considered to be the most important developmental phase of the individual lifespan. The developmental outcomes of this early phase of life impact the level of health and well-being enjoyed by a population in its future. Download Document Documents Socio-demographic Profile 0-5 and Parents: Province of Québec Early child development (ECD) is a cornerstone of human development and childhood is considered to be the most important developmental phase of the individual lifespan. The developmental outcomes of this early phase of life impact the level of health and well-being enjoyed by a population in its future.