Milestones for Ages 15 to 18

Ages 15 to 18 are an exciting time of life. But these years can be challenging for teens and their parents. Emotions can change quickly as teens learn to deal with school, their friends, and adult expectations. Teen self-esteem is affected by success in school, activities, and friendships.

Teens tend to compare themselves with others, and they might form false ideas about their body image. The influence of media can add to a teen's poor body image.

Physical development

Teens have usually entered puberty by age 15.

• During female puberty, most teens by age 15:
  • Have had their first menstrual period.
  • Have nearly reached their adult height.
• During male puberty, most teens:
  • Usually continue to grow taller and gain weight through their teen years.

Thinking and reasoning (cognitive development)

Teens in this age group:

• May understand that people can see the same issue in different ways. But they often feel that their personal views are the ones that are most correct.
• May think they "know everything."

Emotional and social development

Teens in this age group:

• Try to find their place in the world. They are figuring out "Who am I?" and "How do I fit in?"
• May have emotional swings from day to day.
• Seem mature at times, but other times may not.
• May rebel and have difficult behavior.
• Start to seek romantic relationships, which become an important part of their identity.