teens_467x310.jpgBelow is a brief summary of some key milestones for youth aged 15-17 outlined in the Ontario Ministry of Children and Youth Service’s Stepping Stones: A Resource on Youth Development.


It's important to note that while these milestones represent what is common for kids in this age group, a child's development is also affected by individual factors. Some kids will reach milestones at an early age, while others may need more time to develop, and some may not reach that milestone at all.


Visit the Ministry’s website to read the resource in its entirety.


Cognitive Development:
  • Dramatic changes in the brain continue;
  • Brain function becomes increasingly efficient and specialized;
  • The amount of grey matter (neurons or brain cells) continues to decrease as neurons are eliminated in a ‘use it or lose it’ process;
  • The amount of white matter continues to (myelin and axons) increase;
  • These changes result in an increasing ability to process complex information and learn new concepts;
  • The prefrontal cortex continues its slow maturation process, expanding ‘executive functions’ such as the ability to monitor, organize, plan, make decisions, anticipate consequence and control impulses and gratification (this development depends to a large degree on life experiences);
  • Processing speed (how quickly new information is absorbed) increases until around age 15-16.


Emotional Development:
  • Those in later adolescence feel emotions more intensely, are more sensitive to pleasure and reward and are particularly vulnerable to stress;
  • Can be more likely to participate in risky behaviour;
  • The capacity for self-regulation and for decision making continues to lag behind the ability to feel emotions;
  • True empathy for other people begins to form but will not be fully developed until adulthood;
  • The internalization of motivations (moving from wanting to get benefit and avoid rewards towards doing things out of interest or desire) continues to develop.


Social Development:
  • A sense of self-identity continues to develop (may include many components, including gender identity, social group identity, and spiritual identity);
  • Self-concepts become more differentiated across different contexts (may be deferential with parents but a leader among friends and shy in class) and conflicts in self conception begin to emerge (possibly resulting in anxiety about who they really are);
  • Around ages 15-16, adolescents begin to become more certain of their ability to achieve goals again, after a continued decline since the start of puberty;
  • Self-esteem begins to decrease in early adolescence (particularly among girls) and often continues to decline into adulthood at which point it rises again on an upward trend into old age;
  • Teens (particularly those from minority groups) continue to show an increase in social group-esteem (show increasing pride in belonging to their social group) which continues into adulthood;
  • Romantic relationships begin to emerge, however, they are usually not based on emotional intimacy but rather fun and camaraderie; sexual behaviour may progress;
  • Relationships with parents may suffer as teens choose to spend more time with their friends and find themselves more often in conflict with their parents; this peaks in mid-adolescence (15-16) and usually declines afterward.


Physical Development:
  • Changes in cardiovascular endurance, muscle strength and endurance, and flexibility continue, all depending largely on their levels of physical activity; in general physical activity continues to decline into adulthood;
  • Sleep pattern disruption continues, often causes young people to feel wide awake and alert until late at night and have difficulty getting up in the morning, often resulting in sleep deprivation;
  • These changes to body and mind have significant impact on how young people feel about the appearance of their body (females, whose body mass tends to increase during puberty, may develop negative body image, affecting mood, eating habits and mental well-being; males, on the other hand, put on muscle mass, start to develop a masculine shape and generally become more satisfied with their physical appearance);
  • Caloric intake, especially around a growth spurt, can skyrocket. The body’s need for protein and calcium to build muscle and bones also increase.