Swain: We're constantly struck with the paradox that children are born with a tremendous capacity to learn, and yet many children have great difficulty in school, and grow up to lack the facility with reading, writing and oral language that is so needed in a complex society. Families across cultures and languages are successful in supporting their children's learning and achievement, and we have much to learn from these successful families and their children. And yet other families have great difficulties. . . . Yet, within families with great difficulties, we have children who are resilient to these forces, and others who suffer great harm.