HomeHealth & BehaviorHealth & Nutrition

Child development: 13- to 16-year-olds

Kids in early adolescence experience tremendous intellectual, physical, social, and emotional changes. What can parents expect to see?

By Nancy Firchow, M.L.S.

Middle adolescence is a time of blossoming development — the insecure, inwardly focused 13-year-old becomes a cheerful, charming 16-year-old looking toward the future. During this time your child's thinking skills take a decidedly adult turn, his body matures, and friends and social networks outside the family become increasingly important. Now is when you will really begin to get a glimpse of the adult your child will become.

Physical development

Boys and girls still exhibit markedly different levels of physical maturity as they enter middle adolescence. Girls' rapid growth is generally tapering off, while many boys have yet to see the beginning of their much anticipated growth spurt. By the end of this period most girls will be near their adult height; boys may continue to grow until age 18 or 19.


  • growth in height continues, but at a slower pace than earlier; adult height is reached by age 16 or 17
  • breast development continues
  • pubic hair thickens, darkens, and takes on adult triangular pattern
  • underarm hair thickens
  • hips widen; fat deposits in buttocks, legs, and stomach increase
  • menstrual periods become regular; ovulation is established; pregnancy becomes possible


  • rapid growth in height and weight
  • muscles fill out and strength increases dramatically
  • voice deepens
  • pubic and underarm hair appears and thickens
  • body hair increases
  • penis, scrotum, and testes enlarge
  • ejaculation and nocturnal emissions occur

Both girls and boys:

  • always hungry; appetite is great
  • need for sleep increases; may sleep quite late on weekends
  • oily skin and acne may be problematic
  • sweating increases
  • rapid growth may cause clumsiness and lack of coordination
  • sexual desires and fantasies increase

Intellectual development

Between 13 and 16 your child's ways of thinking about himself, others, and the world shift to a much more adult level. He enters middle adolescence with a focus on things he can experience here and now, and moves to being able to imagine the range of possibilities life holds. Expect the following changes as a progression of development rather than as age-based milestones:

  • arguing skills improve (and are demonstrated often and with great passion)
  • reasoning skills improve:
  • begins with the ability to apply concepts to specific examples
  • learns to use deductive reasoning and make educated guesses
  • learns to reason through problems even in the absence of concrete events or examples
  • becomes able to construct hypothetical solutions to a problem and evaluate which is best
  • focus on the future develops:
  • begins with a present focus, mixed with some fantasy
  • learns to recognize that current actions can have an effect on the future
  • starts to set personal goals (and may reject goals set by others)
  • decision-making skills improve:
  • begins to independently differentiate right from wrong and develops a conscience
  • learns to distinguish fact from opinion
  • learns to evaluate the credibility of various sources of information
  • becomes able to anticipate the consequences of different options
  • may challenge the assumptions and solutions presented by adults

Comments from readers

"Pretty accurate about 16 when i wad 15 i though about everyone jugging me now i dont give a crap and realatioships do get intense this girl christa i cant get her out of my head she is so beautiful so if your kid has a girlfriend dont embarris him/her your kid is gonna have S.E.X its hard for dads to see there daughter having it and moms stop thinking of your son as your baby we hate that "
"good article but misses the point of '9-12' years lol "
"i am 13 years old and im not any of that of what you say that is a LIE if ive ever heard one.... love ya! "
"this was useful, thankyou. "
"it is nice "
"why is the site talking on older children when i asked about an 11 year old childs do we get info out this way?????"
"i think that this site is good "
"This informations are very accurate and right."
"This article does not refer to any developments that 9,10,11, or 12 year old goes through. It focuses more on 13 year old and young adults."
"Even though the title says 9 to 12 year olds it talks about 13 to 16. Could you send me the 9 to 12?"
"Why does this article say it will talk about 9 to 12 year olds and then talk about older children (13 to 16 year olds)??"
"it only talks about interlectual and physical but not emotional or social "
"i like this link alot "
"Call me silly, but the title of this article refers to 9-12 year olds, but seems to actually be talking to 13-16 year olds... Is this mis-posted?"
"article mis-titled - should re-title targeting 13-16 year olds. That being said, do you have an article for 9-12 year olds? "
" 13 and i dont think 13-year-olds only care about themselves!!!!!!!!!!"
"This article intended for Child Development of ages 9 to 12 is incorrect. The information provided is for for ages 13 to 16 as provided in the text. Where is the Child Development information for children 9 to 12 years old? Thank you for your help."