Only man and a few other primates experience a prolonged period of sexual immaturity and the ' catastrophic ' onset of puberty. What are the mechanisms involved in delaying and then trigering the final maturation process? What are the roles played by genetic and environmental factors?
John Maddox discusses some of these questions with Professor J. M. Tan ner of the Institute of Child Health. London. and other speakers at last week's International Symposium on Adolescent Medicine held in Washington.
Producer alison RICHARDS