Developmental transitions in adolescents are both gradual and sudden, although the process leans very heavily towards the gradual, with physical growth occasionally occuring in a more sudden "spurt" in which an adolescent can very quickly grow physically into an individual of significantly larger stature. Teenage boys, for example, often experience a "growth spurt" that can result in dramatic transformation of their physical dimensions, and can even cause joint problems, as tissue connecting rapidly changing bones that comprise joints have fail to maintain pace with the growth of the bains. In fact, adolescent children can develop Juvenile idiopathic arthritis. While the knees are often the joints most directly affected by growth spurts, teenage hip joints are also known to occasionally suffer the effects of physical growth.
While growth spurts are real and occur in fairly quick procession, many, more subtle developmental changes occur much more gradually. The adolescent brain is continuing to grow, as it will until about the age of 20. For many years, it was widely believed that the most substantive brain development occurs among children in the single-digits of age. More recent research involving Magnetic Resonance Imaging (MRI) has demonstrated that substantial development of the brain continues to occur through adolescence. In that sense, neurological developments are far more gradual than used to be thought.
Behavioral characteristics among adolescents can also occur somewhat quickly, as is evident in incidences of teenage depression and the introduction to illegal drug use. A direct outgrowth of the continued development of the adoscent brain, depression, antisocial behavior, and greater exposure to peer pressures are all products of the gradual development of the brain yet which can manifest themselves relatively quickly.
The ten years associated with adolescence (generally considered to be from age 10 to age 20) are characterized by continuous development of the physical body along every step of the way. The early stages of adolescence reflects substantial physical and emotional transformations for both genders, with development of sexual organs and puberty the most prevalent defining characteristic. As this stage passes, and puberty is completed, a marked difference between the genders becomes more obvious, as boys continue to grow and develop greater strength, while girls largely reach their peak with regard to height. As individuals reach the final stage of adolescence, they have a much greater capacity to identify and analyze problems and to make decisions that best serve their interests. Transitions of the body has continued through this state, with males and females both reaching full maturity.
The human body evolves through definable stages. Within each stage, transitions can occur quickly. Looked at in terms of birth-to-adulthood development, it can appear considerably more gradual. The crucial years of adolescence, however, are far more dynamic than one might think.