Urie Bronfenbrenner is frequently quoted for his idea that “every kid needs at least one adult who is crazy about him.” In this extract he develops the idea in a classic piece of writing well worth close reading by all who have anything to do with kids:
Five Critical Processes for Positive Development
Proposition 1 
 In order to develop – intellectually, 
	emotionally, socially, and morally – a child requires participation in 
	progressively more complex reciprocal activity, on a regular basis over an 
	extended period in the child's life, with one or more persons with whom the 
	child develops a strong, mutual, irrational, emotional attachment and who is 
	committed to the child's well-being and development, preferably for life.
Proposition 2 
The establishment of patterns of progressive 
	interpersonal interaction under conditions of strong mutual attachment 
	enhances the young child's responsiveness to other features of the immediate 
	physical, social, and – in due course – symbolic environment that invite 
	exploration, manipulation, elaboration and imagination. Such activities, in 
	turn, also accelerate the child's psychological growth.
Proposition 3 
The establishment and maintenance of patterns of 
	progressively more complex interaction and emotional attachment between 
	caregiver and child depend in substantial degree on the availability and 
	involvement of another adult, a third party who assists, encourages, spells 
	off, gives status to, and expresses admiration and affection for the person 
	caring for and engaging in joint activity with the child.
Proposition 4 
The effective functioning of child-rearing 
	processes in the family and other child settings requires establishing 
	ongoing patterns of exchange of information, two-way communication, mutual 
	accommodation, and mutual trust between the principal settings in which 
	children and their parents live their lives. These settings are the home, 
	child-care programs, the school, and the parents' place of work.
Proposition 5 
The effective functioning of child-rearing 
	processes in the family and other child settings requires public policies 
	and practices that provide place, time, stability, status, recognition, 
	belief systems, customs, and actions in support of child-rearing activities 
	not only on the part of parents, caregivers, teachers, and other 
	professional personnel, but also relatives, friends, neighbors, co-workers, 
	communities, and the major economic, social, and political institutions of 
	the entire society. 
Bronfenbrenner notes: "I am sometimes asked up to what age do these principles apply. The answer is debatable, but I would say anytime up to the age of, say, 99."
Bronfenbrenner, U. (1990) Discovering What Families Do, in Rebuilding the Nest: A New Commitment to the American Family. Family Service America, 1990.