In studying adolescent development, adolescence can be defined biologically, as the physical transition marked by the onset of puberty and the termination of physical growth; cognitively, as changes in the ability to think abstractly and multi-dimensionally; or socially, as a period of preparation for adult roles.
Major pubertal and biological changes include changes to the sex organs, height, weight, and muscle mass, as well as major changes in brain structure and organization.
Cognitive advances encompass both increment in knowledge and in the ability to think abstractly and to reason more effectively.
The study of adolescent development often involves interdisciplinary collaborations.
This is triggered by the pituitary gland, which secretes a surge of hormonal agents into the blood stream, initiating a chain reaction to occur.