However, early puberty is not always positive for boys; early sexual maturation in boys can be accompanied by increased aggressiveness due to the surge of hormones that affect them.
This is triggered by the pituitary gland, which secretes a surge of hormonal agents into the blood stream, initiating a chain reaction to occur.The male and female gonads are subsequently activated, which puts them into a state of rapid growth and development; the triggered gonads now commence the mass production of the necessary chemicals.The accelerated growth in different body parts happens at different times, but for all adolescents it has a fairly regular sequence.The first places to grow are the extremities—the head, hands and feet—followed by the arms and legs, then the torso and shoulders.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.
The end of adolescence and the beginning of adulthood varies by country and by function.
Furthermore, even within a single nation state or culture there can be different ages at which an individual is considered (chronologically and legally) mature enough for society to entrust them with certain privileges and responsibilities.
Puberty occurs through a long process and begins with a surge in hormone production, which in turn causes a number of physical changes.
It is the stage of life characterized by the appearance and development of secondary sex characteristics (for example, a deeper voice and larger adam's apple in boys, and development of breasts and more curved and prominent hips in girls) and a strong shift in hormonal balance towards an adult state.
Facial hair is often present in late adolescence, around ages 17 and 18, but may not appear until significantly later.