Issues and advances in adolescent growth and development.

The differences between individuals in tempo of growth, leading to early or late appearance of puberty, are of great importance at adolescence. Late developers, and particularly those who are genetically small as well as late, often suffer acutely and may keep scars of their suffering for years afterward. These individuals need sympathetic support and counseling, which can only be forthcoming from someone who understands thoroughly the auxology of adolescence and is able to tell the adolescent precisely and correctly what will happen in the next six months, one year, and two years. Educating the counselors, and educating the children before they enter adolescence, is a task of importance and immediacy. The physiologic mechanism of tempo is entirely unknown at present, and the major job of research is to remove this ignorance. Close collaboration is needed with pediatric endocrinologists and endocrinologists working with nonhuman primates. A prime need here is for the building of further auxologic and endocrinologic tools and the development of testable models of growth regulation.