Differentiates between several terms used to refer to the five-year period between ages 9 through 13 (for example, "youth,""pubescence,""puberty," and "preadolescence"). Theories related to preadolescence, including the developmental theories of Piaget, Kohlberg, and Erikson, are briefly discussed, and social, emotional, sexual, and physiological characteristics of the preadolescent stage are reviewed. (RH)