Although this quote was not intended to describe the period of adolescence, it does bear some striking truths to the revolution that is occurring during this time. Adolescence is a particularly exciting and uniquely vulnerable period of development. Not since infancy has the individual undergone so many changes at such a high rate of speed (Carnegie Council on Adolescent Development, 1996). These changes are occurring across multiple developmental systems- physiological, cognitive, and psychosocial. Additionally, these changes are occurring in part in reaction to the individual's environment. That's right. While development in infancy could be considered generic such that the organism is at that time primed to adapt to any environment (e.g., aboriginal tribe or middle-class American-they all begin the same), development during adolescence is designed to fit the organism more efficiently into his or her environment or context. Thus, development during the period of adolescence reflects an active interplay between the organism and his or her context. Such contexts include the individual, family, friends, community, and culture.