Social Relationships and Their Developmental Significance
an article in American Psychologist by Willard W. Hartup
(our site's article review)
Social competence emerges mainly from children’s experience in their close relationships with people. Experience in both vertical and horizontal relationships is necessary for children’s optimum growth. These two types of relationships serve different functions in children's development and they emerge at different times. The quality of these relationships affects them in ways that last.
Horizontal relationship is a relationship between equals, as opposed to a relationship between superiors and inferiors, which is vertical relationship.