Development Milestones – Adolescent Years

Development Milestones │ Adolescent Years

This period signifies substantial changes in a teenager’s cognitive, emotional, and social development, as well as physical maturation. Teens are crafting their individuality and beliefs, with friendships remaining vital. Simultaneously, they’re gaining a clearer self-identity and growing interests. This phase also marks preparation for greater independence and responsibility, often involving part-time work and preparations for leaving home post-high school.

There are three broad stages of development: early childhood, middle childhood, and adolescence organized around the five primary skills of development in each stage: cognitive, physical, social and emotional, language and communication, and adaptive. The boundaries of each developmental stage are not rigidly fixed. Every child is unique, and as a result, each child or young adult will have their own distinct learning and behavioral patterns, along with individual challenges that may necessitate attention and intervention. These developmental milestones serve as general guidelines, but they may not necessarily signify the presence of a problem.

Physical Skills
Physical development includes growth and functionality of muscles and body parts. Gross motor skills involve the large muscles in the arms, legs and torso. Fine motor skills involve the movement and use of hands and upper extremities.

Cognitive Skills
Cognitive development is critical to a child’s growth. It describes how a child’s brain  develops, and includes skills such as thinking, learning, exploring and problem solving. It also affects other areas of a child’s development, including language and social skills.

Language Skills
Language development milestones measure the child’s receptive (hearing and understanding) and expressive (speech) abilities. Language development starts with sounds and gestures, then words and sentences.

Social/Emotional Skills
Social and emotional development focuses on a child’s ability to express emotions effectively, follow rules and directions, form positive relationships with others, and build confidence.

Adaptive Developmental Skills
Referring to age-appropriate life skills, "adaptive and self-care skills" focus on the ability for the child to learn self-help skills and self-sufficiency skills so they can live independent and productive lives as adolescents and adults. 

Adolescence (12-18 Years+)
Adolescence signals diverse, confusing, even frightening changes due to significant physical, emotional and cognitive growth, new situations, responsibilities, and people.  

Frequent mood swings, episodes of depression, and other psychological challenges are not uncommon. While these shifts are often attributed to hormonal changes, it’s crucial to recognize that your child will grapple with various challenges and confrontations, leading to fluctuating and inconsistent behaviors that tend to stabilize with time and maturity.

As adolescents transition toward adulthood, they experience a compelling desire for greater independence from their families. Cognitively, they gain the capacity to address more abstract and hypothetical problems, representing a significant stride toward emotional autonomy. This shift involves a notable transformation in their modes of thought and reasoning, often leading adolescents to rely more on their peers for guidance and emotional support, as opposed to their families.

12-14 Years
Often referred to as early adolescence, your child grows taller and stronger and also starts to feel and think in more mature ways, signaling the roots of a transition to adulthood.  

This is a time of many physical, mental, emotional, and social changes. Puberty begins. Hormones activate. Most boys begin to grow facial and pubic hair, and their voices deepen. Most girls begin to grow pubic hair as well as breasts and start their periods. Early adolescents often worry about these myriad changes and how they are now viewed by others.

  • Growth spurt begins with the accompanying growth pains and cramps, and the need to sleep and eat more.
    • Girls begin at about age 11-12.
    • Boys begin at about age 13-14.
  • With girls, puberty is marked by physical changes include increased body fat, beginning of breast enlargement, pubic hair growth, widening hips, underarm hair growth, oilier skin and hair, and the first menstrual period.
  • With boys, puberty is marked by physical changes might include larger muscles, vocal changes, oilier hair and skin, the beginning of underarm, facial and pubic hair, darkening scrotum, and testicle and penis growth.
  • Boys may lag girls in height during these years, but they usually end up taller.
  • May be a little awkward or clumsy as brains need time to adjust to longer limbs and bigger bodies.
  • Thinks in concrete ways but gradually begins to grasp abstract and symbolic concepts and considers the difference between logical thinking vs. abstract thinking.
  • Develops deductive reasoning abilities and demonstrates a more strategic and methodical approach to problems. 
  • Begins to see that issues are not just clear-cut, and that information can be interpreted in different ways.
  • Typically focuses on the present but begins to understand things in the long-term.
  • Develops a stronger sense of right and wrong. Understands shades of gray, wrestles with abstract concepts like love or justice, and formulates values based on thinking and analyzing as opposed to only by feeling or experiencing.
  • Develops better decision-making skills.
  • Can initiate and carry out their own tasks without the supervision of others.
  • Becomes more independent from families.
  • May form strong friendships and prefer to be with their friends or on their own rather than with family members.
  • May look to friends, instead of parents, for advice. Shows more interest in and influence by peer group.
  • Searches for intimacy, tends to romanticize.
  • Focuses on themselves; going back and forth between high expectations and lack of confidence.
  • May grow sullen and aloof; loses patience with meaningless activity.
  • Shows more interest in friends and less interest in family. Looks to friends, instead of parents, for advice. Shows more interest in and influence by peer group with whom they form strong and complex friendships.
  • Begins to accept and enjoy their own uniqueness but still seeks approval from peer groups.
  • Begins to see self from viewpoint of others; looks for confidence from others in their decisions.
  • Expresses less affection toward parents; sometimes might seem rude or short-tempered.
  • Focuses on themselves; going back and forth between high expectations and lack of confidence.
  • Vacillates between distress and happiness which can lead to self-destructive and risky behavior tempered by questioning authority and/or succumbing to peer pressure.
  • May be self-centered and can be insensitive to others.
  • Is better able to express feelings through talking.
  • Begins to reason, think abstractly, and apply logic.
  • Demonstrates an increased ability to look beyond literal interpretations and understands the metaphoric uses of language.
  • Increases in metalinguistic awareness (the ability to think about how language is used—to persuade, to correct, to endear, etc.).
  • Begins to understand how to form analogies.
  • Balances complex ideas and the ability to manipulate them in their head.
  • Understands the subtleties of language improving their ability to understand multiclause sentences.
  • Able to comprehend proverbs and detect sarcasm.
  • Grows into strong readers and uses their language and literacy skills across the subject areas in school, and as a tool in other areas of importance.
  • Enjoys demonstrating acquired knowledge.

Actively shows more interest in physical attractiveness (body and looks), often believing they are the center of attention making them painfully self-conscious and hyper-sensitive to comments and insults.  

Adolescence often radically changes the body. Girls and boys usually begin puberty around the same time their parents did. 

In this age group, teens begin making more of their own choices about friends, sports, studying, and school. They become more independent, with their own personality and interests, although parents remain very important.

14-16 Years
In the mid- to late-teenage years, kids start thinking not just about their own lives, but also more about how the world works. This is a pivotal age as they recognize they also are heading down a path toward adulthood.  They are developing their unique identity, gaining independence, and likely exploring (or thinking about) romantic relationships and learning the skills they need for a successful future.

During these years, teens seem grow comfortable in their own skin, eager to take on the world. They are also taking on more responsibilities, navigating high school, and gaining more independence. They may even behave like they know everything. This attitude—often mixed with a hint of rebellion—can be par for the course. On the flip side, they may also experience academic challenges, peer pressure, risky behaviors, and show insolence and disrespect.

Turning 16 is a big deal to most teens. Not only does their freedom expand with the addition of a driver’s license, but they also are becoming more cognizant of what they want to do in their future. Those who plan to attend college may be visiting universities or preparing to take the appropriate standardized tests.

  • Growth spurt begins with the accompanying growth pains and cramps, and the need to sleep and eat more.
    • Girls begin at about age 12. Boys begin at about age 13.
  • Most males will have started their growth spurt, and puberty-related changes continue. They may have some voice cracking, for example, as their voices deepen. Some develop acne. Physical changes may be nearly complete for females, and most girls now have regular periods.
  • May be a little awkward or clumsy as brains need time to adjust to longer limbs and bigger bodies.
  • Thinks in concrete ways but gradually begins to grasp abstract and symbolic concepts and considers the difference between logical thinking vs. abstract thinking.
  • Develops deductive reasoning abilities and demonstrates a more strategic and methodical approach to problems. 
  • Begins to see that issues are not just clear-cut, and that information can be interpreted in different ways.
  • Typically focuses on the present but begins to understand things in the long-term.
  • Develops a stronger sense of right and wrong. Understands shades of gray, wrestles with abstract concepts like love or justice, and formulates values based on thinking and analyzing as opposed to only by feeling or experiencing.
  • Develops better decision-making skills.
  • Can initiate and carry out their own tasks without the supervision of others.
  • Becomes more independent from families.
  • May form strong friendships and prefer to be with their friends or on their own rather than with family members.
  • May look to friends, instead of parents, for advice. Shows more interest in and influence by peer group.
  • Searches for intimacy, tends to romanticize.
  • Focuses on themselves; going back and forth between high expectations and lack of confidence.
  • May grow sullen and aloof; loses patience with meaningless activity.
  • Shows more interest in friends and less interest in family. Looks to friends, instead of parents, for advice. Shows more interest in and influence by peer group with whom they form strong and complex friendships.
  • Begins to accept and enjoy their own uniqueness but still seeks approval from peer groups.  Begins to see self from viewpoint of others; looks for confidence from others in their decisions.
  • Expresses less affection toward parents; sometimes might seem rude or short-tempered.
  • Focuses on themselves; going back and forth between high expectations and lack of confidence.
  • Vacillates between distress and happiness which can lead to self-destructive and risky behavior tempered by questioning authority and/or succumbing to peer pressure.
  • May be self-centered and can be insensitive to others.
  • Is better able to express feelings through talking.
  • Demonstrates an increased ability to look beyond literal interpretations and understands the metaphoric uses of language.
  • Increases in metalinguistic awareness (the ability to think about how language is used—to persuade, to correct, to endear, etc.).
  • Begins to understand how to form analogies.
  • Balances complex ideas and the ability to manipulate them in their head.
  • Understands the subtleties of language improving their ability to understand multiclause sentences.
  • Able to comprehend proverbs and detect sarcasm.
  • Grows into strong readers and uses their language and literacy skills across the subject areas in school, and as a tool in other areas of importance.
  • Enjoys demonstrating acquired knowledge.

Adolescents tend to become more comfortable with their bodily transformations during later stages of adolescence, although their outward appearance continues to hold significance. Throughout this period, forging connections with peer groups plays a vital role in their self-discovery and self-image development. It’s common for adolescents during this phase to frequently switch friend circles, experiment with their clothing choices, and explore new interests. 

During this period, teens are deeply embedded in their social standing. Texting and social media are often very important at this age. Most teens have the ability for complex thought and can express their thoughts and opinions verbally. Peer friendships and peer experiences become very important in their social and emotional development. They spend a lot of time talking with peers, not so much with their parents as their opinions or beliefs are sometimes different than their parent or caregiver’s beliefs.

Begins to reason, think abstractly, and apply logic. Begins to focus thinking on emerging role in adult society. Begins to understand how the world works and their own potential in that world.  Increased thoughts about more global concepts such as justice, history, and politics.  

16-18 Years+
The latter part of adolescence marks a period of swift transformation in how teenagers think, feel, and interact with others and how their bodies grow.  By this phase, your young adult has finished puberty and grown accustomed to his or her new adult body. Most girls will be physically mature by now, having completed puberty. Boys, however, may still be maturing physically during this time.

Now, they start to assert their independence, nurture their distinctive personalities and viewpoints, discover their individual identity, and cultivate a more defined sense of self.

  • By this age, the child has finished puberty and grown accustomed to his or her new adult body.
  • Most girls will be physically mature by now and most will have completed puberty. Boys might still be maturing physically during this time.
  • Acne occurs in the majority of teenagers, and females will reach menarche during this stage. Other physical changes include the final stages of breast, penile and pubic hair development, and many teenagers will reach, or be close to reaching, their adult height and weight. It is common for adolescents to physically develop at different rates.
  • 95% of adult height reached.
  • Understands long and complicated instructions with many different directions.
  • Understands figurative language, makes predictions based on information not given to them and understands sarcasm.
  • Will ask for clarifications when needed. Understands double meanings and subject words.
  • Uses activities that will allow them to identify their own philosophies.
  • Enjoys discussing world situations and events as well as personal activities.
  • Shows more concern about future school and work plans.
  • Is better able to give reasons for their own choices, including about what is right or wrong.
  • Uses language to persuade and negotiate with others.
  • Keeps up with rapidly-changing talk. Switches language styles to suit the environment, situation and/or communicative partner.
  • Has a high interest in social activity with a strong desire for status in peer group.
  • More comfortable seeking advice from older people and their parents and more open to feedback.
  • Better able to evaluate opinions without adopting the same ideas as everyone around them. Develops an emerging ability to make independent ​decisions and to compromise. 
  • Uses language to solve complex problems during a conversation.
  • Understands long and complicated instructions with many different directions. 
  • Understands figurative language, makes predictions based on information not given to them.
  • Is better able to give reasons for their own choices, including about what is right or wrong.
  • Understands double meanings and subject words as well as sarcasm.
  • Gains a better understanding and awareness of their sexuality.
  • Gains better control over emotions. 
  • Begins to develop more serious relationships with an increased capacity for sensual and tender love. 
  • Develops a clear sexual identity and gains a good sense of their bodies and what they can do.
  • Struggles with fear of the future—as well as the fear of failure.

Dating becomes a common activity for some teens as they assess their ability to attract others. Some may explore their sexual identities and orientations; others discover a deeper capacity for caring and sharing and for developing more intimate and romantic relationships and sexuality.

Able to comprehend a higher-level abstract thinking — the ability to think about concepts and ideas without being tied to a specific example. This is a tool that helps us solve problems, communicate effectively, and better understand ourselves and others.

Many teens develop the ability to self-reflect and can begin to understand their own actions in a moral context and how they relate to their world.

It is a time of much introspection, and they may struggle with feelings of inner turmoil and question their place in the world with a mix of emotions: happiness, nostalgia and apprehension including struggling with fear of the future—as well as the fear of failure.

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Adaptive and self-help skills fall into the following categories:

  • Self-help skills that involve the “activities of daily living” (ADL) such as getting dressed, going to the bathroom, cleaning teeth, and self-feeding
  • Communication skills such as speech and language (including expressive and receptive abilities)
  • Motor coordination skills which include gross motor skills (like jumping and hopping) and fine motor skills (like drawing or stacking objects)
  • Social interaction skills such as initiating peer contact, group activities, knowing the rules of manners and conversation, using the telephone
  • Self-sufficiency skills such as being safe, asking for help, and personal responsibility (e.g., counting and using money)
  • Cognition skills like higher-order reasoning, problem-solving, and executive decisions
  • Organization skills needed to follow daily routines and understand timing and completion. This category also includes recognizing sequences and patterns. Organization skills are essential to the successful completion of homework, assignments, and future success in the workplace.
Boys in Puberty

Female Puberty