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Normal Development: 15 to 17 Years Old

Each child is unique. While some behavior and growth milestones tend to happen at certain ages, a wide range for each age is normal. It is okay if your teen reaches some milestones earlier and others later than the average. If you have any concerns about your teen's development, check with your healthcare provider. Here's what you might see your teen doing between 15 and 17 years of age.


  • May stress over school and test scores.
  • May have high expectations and low self-image.
  • Seeks privacy and time alone.
  • Worries that they are not physically or sexually attractive.
  • May complain that parents try to keep them from doing things independently.
  • Start to want both physical and emotional closeness in relationships.


  • Seeks friends who share the same beliefs, values, and interests. Friends become more important.
  • Explores romantic and sexual behaviors with others.
  • May be influenced by peers to take risks with alcohol, tobacco, sex, or other things.


  • Is better able to set goals and think in terms of the future.
  • Has a better understanding of complex problems and issues.
  • Starts to develop moral ideals and to select role models.


  • Most girls complete the physical changes related to puberty by age 15.
  • Boys continue to mature and gain strength, muscle mass, and height. Testicles get bigger, the voice changes, and pubic hair starts to grow.
Written by Robert M. Brayden, MD, Professor of Clinical Pediatrics, University of Colorado School of Medicine.
Pediatric Advisor 2019.4 published by Change Healthcare.
Last modified: 2012-09-25
Last reviewed: 2018-05-09
This content is reviewed periodically and is subject to change as new health information becomes available. The information is intended to inform and educate and is not a replacement for medical evaluation, advice, diagnosis or treatment by a healthcare professional.
© 2018 Change Healthcare LLC and/or one of its subsidiaries
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