And finally, let us see what must be done as follow-up to Habitat II, to give effect to the entitlements and protection of the Convention, particularly in urban settings. There is frequent reference to the concept of vulnerability of children in the policies, programmes, and advocacy efforts of international organizations and agencies that address the needs of children. What is not always appreciated is that vulnerability is a function of the biophysiological, cognitive, behavioural, and social changes that are the defining features of the growth and maturation of infancy, childhood, and adolescence. Developmental health encompasses all these dimensions and is attained when the child is provided with an enabling environment for its development, i.e., sufficient nourishment, care, and protection, including age- appropriate psychosocial and cognitive stimulation. The interaction of these elements with the genetically pre-programmed endowment of the child will result in the healthy transition from one stage or phase of development to the next stage.
Early childhood is a particularly critical period of development in the entire lifespan.
Child growth and development can be seen as a series of steps, each one of which requires a combination of critical nutrients, psychological stimuli, and social interactions in order to pass successfully to the next step. The process results in an increasingly mature, well-nourished, and healthy individual able to function in a family, community, and wider social setting. Obstacles to the normal developmental process may occur at the molecular, biological, immunological, psychological, or social levels, and at any stage. Some stages in the developmental process are more critical than others. Failure to protect the infant at these stages may result in illness or nutritional problems.