13.3 Stages of Child Development

Child development refers to the stages a child goes through from birth until adulthood.^[1] Nurses must be knowledgeable about stages of child development so they can adapt care according to the child’s age, developmental level, and their individual needs.^[2] As children grow and develop, their physical characteristics and psychosocial needs change. Growth refers to an increase in size, such as in height, weight, or head circumference.^[3] Growth and growth monitoring are further discussed in the “Nursing and Medical Care for the Developing Child” section.

Development refers to changes that occur as an individual matures across their life span. This section will discuss development from infancy through adolescence. Development is multidimensional with changes occurring across three general dimensions called physical, cognitive, and psychosocial^[4]:

• The physical domain includes height and weight, motor skills, sensory capabilities, and the propensity for disease and illness.
• The cognitive domain encompasses intelligence, wisdom, perception, problem-solving, memory, and language.
• The psychosocial domain focuses on emotion, self-perception, and interpersonal relationships with families, peers, and friends.

As children develop, they progress through stages classified as infant, toddler, early childhood (preschool), middle childhood (school-age), and adolescent. The following subsections will describe typical characteristics of children in these stages, focusing on the physical, cognitive, and psychosocial domains.

Infant

Infants include newborns (the first month of life) to twelve months of age. Most children learn to sit, crawl, walk, manipulate objects with their hands, and form basic words by the end of infancy. See Figure 13.4^[5] for an image of an infant.

Physical Domain

Infancy is a time when tremendous growth, coordination, and mental development occur. In general, the weight of a five month old should be double their birth weight, and the weight of a one year old should be triple their birth weight. For example, a newborn weighing seven pounds at birth will weigh about 14 pounds at five months and 21 pounds at one year.^[6]

Other specific physical characteristics that are monitored during infancy are head circumference size, fontanel closure, and brain development. An infant’s head is typically 25% of their overall length, which is proportionally larger than an adult’s head. Head circumference is measured during well-child visits because atypical head circumference growth can indicate developmental disorders. The anterior fontanelle should close by 18 months of age, and the posterior fontanelle should close by 2 months of age.^[7]

The infant’s brain is immature and grows significantly through the first two years of life. While most of the brain’s neurons are present at birth, they are not fully mature. Each neural pathway forms thousands of new connections during infancy and toddlerhood. Experience will shape which of these connections are maintained and which are lost.^[8]

Movement and Motor Development

Reflexes

Basic motor skills (the ability to move) develop over the first two years of life. Motor skill development begins with reflexes (involuntary movements in response to stimulation). Infants are born with involuntary reflexes that are necessary for survival such as the following^[9]:

• Breathing reflexes that include rhythmic breathing patterns to maintain adequate oxygen supply, as well as the cough and sneeze reflex to help maintain airway patency.^[10]
• Body temperature regulation reflexes such as shivering and tucking the legs close to the body to increase body heat and pushing away blankets to decrease body heat.
• A sucking reflex that facilitates feeding by automatically sucking on objects that touch their lips.
• A rooting reflex that causes the infant to turn their head toward any object that touches their cheek. This reflex facilitates searching for a nipple during feeding.

Other reflexes, which are not necessary for survival but indicate good neurological function, include the following^[11]:

• Babinski reflex: When the bottom of their feet are stroked, the infant’s toes fan upward
• Stepping reflex: When the infant’s feet touch a flat surface, their legs move as if walking
• Palmar grasp: Infants tightly grasp any object placed in their palm
• Moro reflex: In response to a loud noise, the infant’s arms and legs extend and their back arches, which is also called the startle reflex

These involuntary reflexes are gradually replaced with voluntary movements within several weeks after birth.

Motor Development

Motor development follows an orderly sequence as infants progress from involuntary reflexes to more advanced motor skills. This development occurs in two primary directions called cephalocaudal (e.g., from head to toe) and proximodistal (from the center of the body outward). An example of this progression in infants would be learning to hold up their heads, sit with assistance, sit unassisted, crawl, pull up, cruise (walk by holding on to furniture), and eventually walk. Nurses and health care providers monitor the motor development of infants and assess if milestones are met.

Cognitive Domain

Infants learn while interacting with the world around them by using their senses. The five senses of sight, hearing, touch, taste, and smell are present in the womb or shortly after birth. Newborns can see high-contrast colors of black, white, and red. Young infants have depth perception and can perceive colors and patterns. Around three to four months of age, infants begin to put objects in their mouths so they can interact with them by using the senses of touch and taste. By nine months of age, an infant develops the concept of object permanence, the understanding that something continues to exist even when it is out of sight. Research demonstrates that infants whose parents and caregivers provide safe opportunities for them to move around their environment and use their senses to interact with the world show faster cognitive development.^[12]

Play

Play is a pleasurable activity engaged in for its own sake. Infant play is initiated by parents or caregivers, such as hanging brightly colored mobiles for the infant to see, talking and singing to the infant, providing toys like rattles, using infant swings or walking the infant in strollers, and playing peek-a-boo. As infants approach 6 to 12 months, parents can place the infant on their stomach on the floor and place toys slightly out of reach to promote crawling. They can teach the infant the names of body parts, food, and people, and provide large toys that can be pushed or pulled.^[13]

Language and Communication

Infants can understand language and develop speech patterns before they are able to articulate sounds. Parents and caregivers can speak to infants with the expectation that they will begin to understand the meaning of words.

Infants begin to vocalize and repeat sounds through cooing within the first few months of life. Cooing is a gurgling, musical vocalization. The infant hears the sound of their own voice and attempts to repeat sounds they find entertaining. They also start to learn the rhythm of conversation, taking turns as they respond when the other person’s vocalization pauses. Initially, cooing consists of vowel sounds like “oooo.” The next stage of vocalizations is babbling, where infants add consonants and repeat syllables such as “nananananana.” By 12 to 13 months, infants speak their first words. At one year old, a typical infant has a vocabulary of about 50 words, which expands to around 200 words by toddlerhood.^[14]

Psychosocial Domain

According to Erikson’s theory of psychosocial development, infants are in the trust vs mistrust stage. If their basic needs for nutrition, warmth, safety, and affection are consistently met by their parents/caregivers, they develop trust. If these needs are not met, the infant learns to distrust others.

At birth, infants exhibit two emotional responses called attraction and withdrawal. They are attracted to pleasant stimuli that provide comfort, stimulation, and pleasure and withdraw from unpleasant stimuli, such as physical discomfort. At around two months of age, infants begin to smile in response to others. By three to five months, they laugh as a sign of attraction, and crying can be a sign of withdrawal. Infants as young as four months can avert their gaze to withdraw from overstimulating sensations. By 12 months, infants can actively approach or withdraw from stimuli by walking or crawling. Between six and eight months, infants may show emotions like frustration, anger, and fear. Fear is often triggered by stranger anxiety (the presence of unfamiliar people) or separation anxiety (the departure of a loved one), with separation anxiety typically peaking around 14 months before decreasing.

Emotional Regulation

Infants rely on their caregivers to assist them with emotional regulation, the process of noticing, managing, and responding to one’s emotions. For example, an infant may display frustration through crying, which prompts a response from the parents or caregivers. Parents and caregivers recognize the emotion and use techniques like holding the infant, speaking calmly, or providing distraction to help reduce the intensity, duration, and frequency of the emotion. Over time, the infant may also learn to self-soothe through actions such as sucking on a finger or pacifier.^[15]

Parents can help infants become aware of emotions by naming them and asking questions. For example, while reading a book, a parent might ask, “Why is the turtle sad in this picture?” Parents and caregivers can also model positive coping strategies. For instance, a mother who feels overwhelmed might say, “Mommy is feeling a little frustrated right now, so I’m going to take a deep breath to calm down,” while gently rocking the baby and maintaining a soothing tone of voice. This demonstrates a calming technique. Parents and caregivers who assist their children in regulating emotions are more likely to have children who are less fearful and fussy, express positive emotions, are easier to soothe, are more engaged in environmental exploration, and have enhanced social skills in their toddler and preschool years.^[16]

Toddler

Toddlers, age one to three years, begin to expand their exploration of the world and learn they can affect their environment through their actions. See Figure 13.5^[17] for an image of a toddler.

Physical Domain

By two years of age, toddlers reach about half of their adult height and 90% of their adult head size. Their appearance and body proportions also change from having relatively short arms and legs to longer, more muscular extremities because of their increased activity. During their second year of life, toddlers typically gain about five pounds and grow about four or five inches.^[18]

Movement and Motor Development

Toddlers are highly active and develop skills such as walking, running, and pulling or pushing toys. They also learn to climb stairs with assistance, help undress themselves, drink from a cup, and use a spoon.^[19]

Toilet training is a major accomplishment at this age due to their expanding cognitive and physical development.^[20] Before a child can be toilet trained, they must be able to sense the urge to urinate and defecate, understand what those feelings mean, and be able to communicate their toileting needs to the parent or caregiver. During toilet training, toddlers learn some urges must be controlled and there is a time and place for certain activities. Nurses can help parents understand the basic concepts of toilet training and reinforce teaching to help the child develop a sense of confidence during this training.^[21],[22] Health teaching about toilet training is further discussed in the “Health Promotion and Anticipatory Guidance” subsection of the “Nursing and Medical Care for the Developing Child” section.

Cognitive Domain

As infants grow into toddlers, their brains continue to develop memory, language, thinking, and reasoning skills. Toddlers enjoy playing hide-and-seek because their mastery of object permanence allows them to remember and search for hidden individuals. They learn by imitating the behavior of adults and older children and begin to understand consequences as they test boundaries, such as the meaning of the word “No.”

By around 18 months, toddlers engage in pretend play, which becomes more elaborate by age three. For example, they may pretend to feed a doll or stuffed animal. They can sort objects by shape and color, follow simple instructions, and solve problems using new strategies rather than repeating previous efforts. Through trial and error, toddlers attempt solutions and learn from the outcomes.^{[23],[24],[25]}

Play

Play is essential for toddler development by helping toddlers learn; build relationships; and use physical skills, social skills, language, and communication. Play provides sensory, physical and cognitive experiences that build connections in the brain. Toddlers typically do unstructured play, meaning it happens based on the toddler’s interest at the time. Unstructured play is important because it allows toddlers to lead play activities, follow their own interests, explore the environment, make decisions. and use their imagination. For example, a toddler might open and close drawers, turn containers upside down, or hide objects in a variety of places. Toddlers also like to play the same game or read the same book many times. Repeating activities allows toddlers to master skills and understand cause and effect. Toddlers are full of energy so physical activities in a safe environment are important. Toddler play varies in pace and focus. For example, if walking outside, a toddler may look at something quickly and move on or they may stop and explore an object for an extended period of time. By age three, toddlers also enjoy “pretend” games like dress-up and playing house. Imaginative and creative play allows toddlers to express and explore emotions like frustration, sadness, and anger.^[26]

Language

Toddlers add a significant number of words to their vocabulary by age two. By about 18 months, they string multiple words together. Toddlers start to convey a whole idea with a few words, such as “Give baby ball” and later expand these short phrases to whole sentences. Toddlers also display echolalia (repeating words and phrases spoken by others) as a normal part of language development and learning. For example, if a parent asks a toddler, “Do you want milk?” the toddler exhibiting echolalia may reply, “Milk, milk,” rather than saying “Yes.” Echolalia generally subsides by age three. If echolalia continues beyond age three, echolalia may be a sign of an underlying developmental delay.^{[27],[28],[29]}

Psychosocial Domain

According to Erikson’s psychosocial theory, toddlers are in the stage of autonomy vs. shame and doubt. Autonomy means they are establishing their independence and learning to do things for themselves, leading to a sense of accomplishment, which fosters a sense of pride. Parents can support this by offering simple choices such as, “Would you like to read the red book or the blue book?” Demonstrating confidence and responding positively to toddler efforts help them build self-confidence and pride in their abilities. On the other hand, restricting independence or discouraging decision-making can lead to self-doubt and low self-esteem. Similarly, parental reactions of fear, anxiety, or embarrassment toward a toddler’s exploration may instill shame and hinder their sense of capability.

Toddlers begin to develop self-awareness between 15-24 months, often using words like “me,” “my,” and “I.” As part of their growing autonomy, they test limits and frequently respond to questions and requests with “No.”^[30] Nurses can guide parents to frame requests as simple choices that avoid this response. For example, instead of asking, “Do you want to wash your hands?” parents can say, “Would you like to wash your hands with bar soap or liquid soap?”

Toddlers also develop the concept of possession and commonly use the word “mine.” Humorous examples of how toddlers view the concept of “mine” are described in the following box.

Toddlers imitate the actions of their playmates and adults and express a wide range of emotions. They may display tantrums and aggressive behaviors such as hitting, kicking, scratching, and biting, often as a way to communicate unmet needs due to limited language skills to effectively express themselves. These behaviors are more likely when toddlers are tired, hungry, unwell, or stressed.^[32]

Emotional Regulation

By age one, toddlers begin to understand that parents and caregivers can help them regulate their emotions. They also start to associate specific emotions with certain situations and may withdraw from upsetting stimuli. Parents and caregivers can support emotional regulation by helping toddlers label their emotions with age-appropriate language and modeling positive coping techniques.^[33]

Early Childhood

Early childhood, or the preschool years, spans ages three to five, before formal schooling begins. During this stage, children develop language, a sense of self, greater independence, and begin understanding how the physical world works. However, this knowledge develops gradually, and preschoolers may have interesting conceptions about size, time, space, and distance. For example, they may fear going down the drain if sitting at the front of the bathtub. A toddler’s fierce determination to do something independently may shift to feelings of guilt in a four year old if their actions receive disapproval from others. See Figure 13.6^[34] for an image of a child in early childhood.^[35]

Physical Domain

During early childhood, the average child grows 2.5 inches and gains between five to seven pounds annually. Growth patterns are influenced by genetics, growth hormones, and environmental factors. Girls are generally smaller and lighter than boys during this stage and most children lose their “top heavy” appearance.^[36]

Movement and Motor Development

Preschoolers need daily exercise and activities that include creativity and free movement. Exercise improves physical and visual awareness, while gross motor skills develop as children engage the large muscles of their body. Around age three, children enjoy simple movements such as hopping, jumping, running back and forth, throwing a ball underhand, and catching large or bounced balls. By age four, they become more adventurous. They often enjoy climbing and activities like kicking a ball toward a target, bouncing a ball under control, hopping on one foot four times, and descending stairs with one foot per step. Around age five, children sprint and enjoy racing, kick a rolling ball, skip with alternating feet, roller skate, jump rope, ride a two-wheeled bike with training wheels, and climb. Preschoolers often struggle to sit still, which can affect family mealtimes. Parents should allow preschoolers to leave the table when they finish eating.^[37]

By age three, children are still developing fine motor skills, often struggling to pick up small objects with their thumb and forefinger and having difficulty placing pieces in a puzzle but are adept at building block towers. By age four, coordination has improved, and by age five, children demonstrate smoother, more coordinated movement with their hands, arms, and body.^[38]

Cognitive Domain

Three year olds have a simple understanding of time and can compare two objects. By age four, they can understand opposites. A five year old can count to ten, recite the alphabet, include imaginary friends or scenarios, and follow rules.^[39],[40]

In the preschool years, children’s thoughts are not well-organized, and they may have a hard time differentiating between reality and fantasy. Magical thinking (the belief that thoughts, feelings, or rituals can influence events in the material world) emerge during this stage, as does animism (the belief that inanimate objects have lifelike qualities and can act on their own). They rely on perception more than logic. For example, parents trying to relieve a preschooler’s fear of monsters may try to give them a “magic spray” to get rid of monsters, rather than using reasoning to prove monsters do not exist. Up to age seven, children may have imaginary friends who are described as helpful or blamed for the child’s misbehavior. Children may mimic their parents in disciplining the imaginary friend.^{[41],[42],[43]}

In early childhood, children develop the ability to mentally represent objects that are not physically present. However, they may not yet understand causation and may believe they are responsible for an illness simply because they misbehaved. During this stage, egocentrism (the inability to distinguish between one’s own perspective and someone else’s perspective) is more pronounced. Children also exhibit centration, focusing attention on one characteristic to the exclusion of all others. For example, when comparing the sizes of glasses, a child may focus only on the height of a glass and not the width when determining which glass is largest. Another example of centration is when a cookie is broken in half and the child believes that they now have two cookies.^[44],[45]

Play

Upon entering preschool, children gain opportunities to play with new peers and develop social skills. Initially, preschoolers may play in a solitary manner, but they progress to parallel play where they play with similar toys independently but near other children. Associative play follows, involving sharing objects and making up games and rules with other children, but the child is still focused on their own actions. Finally, in cooperative play, children shift their focus to other children’s actions and work together for a common goal.^[46] See Figure 13.7^[47] for an image of children exhibiting cooperative play as they work together to build a castle made of blocks.

Play provides preschoolers sensory, cognitive, and physical experiences that are essential for development. Different kinds of play help preschoolers develop and learn in many different ways^[48]:

• Dramatic and pretend play: Preschoolers like to dress-up or act out confusing or scary scenarios to try different roles and explore emotions.
• Messy play: Play with paints, water, sand, or dirt develops senses like touch and smell and gives preschoolers the chance to explore textures, smells, and colors.
• Physical play: Jumping, running, kicking balls, and climbing over playground equipment develops strength, coordination, and balance. It also helps preschoolers test the limits of their physical abilities.
• Singing, reading books, and repeating riddles and silly rhymes: These types of activities help to improve language and vocabulary and develop a child’s sense of humor.
• Sorting games: Activities like sorting blocks help to build basic math skills.
• Outdoor play: Jumping in puddles, looking at insects, running down hills, and lying in the grass are good activities for toddlers’ physical health and self-confidence and allow them to explore the natural environment.
• Simple board games: Board games give preschoolers a chance to learn how to take turns, follow rules, count, and play fair.

Language

Literacy is the understanding of language, encompassing reading, writing, listening, and speaking. Children develop literacy through opportunities to speak, interact with active language partners, and be read to. Parents and caregivers can support preschoolers’ cognitive and language growth by encouraging exploration to develop symbolic thought and engaging as active language partners. By the age of three, a preschooler’s language should be understandable to strangers. Stuttering is common in early childhood and usually resolves on its own; parents should avoid overcorrecting it.^[49]

Psychosocial Domain

Preschoolers ask questions about their bodies and begin to understand the physical differences between boys and girls. Boys often engage in rough-and-tumble, competitive play, while girls tend to prefer collaborative activities. From ages three to twelve, children typically favor playing with same-sex friends.^[50]

Emotional Regulation

Preschoolers are able to understand and differentiate between appropriate and inappropriate expressions of their emotions, but they may struggle to express their feelings verbally. Parents can support their children by helping them recognize their emotions, identify triggers, and learn to manage them effectively. Modeling appropriate emotional regulation allows children to learn by observation, while validating their emotions creates a safe environment for expression. In contrast, emotional dismissal, where a parent ignores or denies a child’s emotions, hinders emotional development.^[51] For example, if a child cries when it is time to leave their friends at preschool, a parent can acknowledge the emotion by saying, “You are feeling sad about leaving your friends,” rather than dismissing it with, “Why are you crying? You are fine.”

Emotions also play a big role in peer relations. Children who are able to control emotional responses are more likely to show social competence. Moody, negative children experience greater peer rejection, while emotionally positive children are more popular among their peers.^[52]

Middle Childhood

Also known as the school-aged period of development, middle childhood spans the ages of six to twelve years. During this stage, much of what children experience is connected to their involvement in elementary and middle school. They acquire new skills, compare themselves to peers, and receive feedback on their abilities through academic and athletic achievements. As their social circles expand to include friends, schoolmates, teachers, and coaches, children gain a deeper understanding of relationships beyond the family.^[53] See Figure 13.8^[54] for an image of a middle school-aged child.

Physical Domain

Growth rates generally slow during the school-aged years. Children tend to slim down while gaining both muscle strength and lung capacity, enabling them to engage in strenuous physical activity for extended periods of time. At the beginning of middle childhood, children appear young, but by its end, they enter puberty. Many children experience a pre-pubescent growth spurt, typically around ages 9-10 for girls and age 11-12 for boys. As they enter adolescence, many girls are taller than their male peers.^[55],[56]

Movement and Motor Development

During the early school-aged years, children gain greater control over their body movements, enhancing both their gross and fine motor skills. An example of a gross motor skill is riding a bike, while tying one’s shoes is an example of a fine motor skill.^[57]

Children should be active for at least 60 minutes every day to foster both short-term and long-term health and to prevent chronic diseases. School-aged children may participate in organized team sports, such as soccer, baseball, or basketball, or more individual sports such as karate or gymnastics. Research shows that participation in organized sports varies based on a child’s age, sex, location, and family income. Children who participate in sports often experience physical, psychological, and social benefits and are less likely to engage in problem behaviors.^[58]

Cognitive Domain

School-aged children show rapid development in cognitive skills. Their ability to pay attention, problem solve, use judgment, and regulate emotion improves as the prefrontal cortex matures. This section of the brain continues to develop throughout childhood and adolescence. Six year olds tend to be easily distracted and may leave tasks unfinished, while children ages seven to ten are better able to focus for longer periods and complete tasks.^[59]

According to Piaget’s theory of cognitive development, school-aged children are in the concrete operational stage. At this stage, they can think logically and systematically when dealing with concrete information, which means they better understand things they can directly experience. They are also developing symbolic thinking, which allows them to learn to read, interpret the time on a clock, and count money. They can solve various problems verbally across a range of ideas. However, they typically struggle with solving hypothetical problems at this stage.^[60],[61]

School-aged children understand concepts such as the past, present, and future, which enables them to plan and work toward goals, such as completing chores to earn spending money for a desired item. They can also process more complex ideas, such as addition, subtraction, and cause-and-effect relationships. Children in this stage exhibit genuine enthusiasm for learning new things. They are eager to acquire the skills necessary to understand the world and others around them, gaining self-confidence in the process.^[62],[63] Nurses teach parents and caregivers to guide children in setting academic goals and suggest ways to achieve those goals, such as setting aside a quiet area in the home to do homework.

Play

School-aged children need plenty of time for unstructured and structured play. Self-directed, unstructured play lets children decide what they want to play and how to do it. Unstructured play is valuable because it encourages children to explore ideas, think creatively, and develop hobbies. Structured play, such as participating in organized team sports or other extracurricular activities, help children develop problem-solving skills, learn about their physical and emotional limits, and develop friendships.^[64]

Psychosocial Domain

According to Erikson’s theory of psychosocial development, school-aged children are in the industry vs. inferiority stage. This is a very active time where children can gain pride in their accomplishments in school, sports, and social activities. If they perceive themselves as successful in these endeavors, they develop a sense of competence for future challenges. However, if they feel that they are not measuring up to their peers, feelings of inferiority and self-doubt may arise. Erikson believed that these feelings could persist into adulthood. To help navigate this stage successfully, nurses teach parents and caregivers to encourage children to explore their personal interests and abilities and to use constructive feedback from adults to improve their skills or seek alternative activities based on their strengths.^[65]

Children in middle childhood develop a more realistic sense of their strengths and weaknesses in comparison to their peers. A child’s self-concept is shaped by feedback from peers, family members, teachers, and coaches regarding their abilities. According to Erikson, experiencing failure during an attempted effort is not necessarily a bad thing, but instead can be viewed as a type of feedback. This feedback helps children develop a sense of modesty about their skills and abilities, with an ideal balance between competence and humility.^[66]

Children in middle childhood begin to form friendships in more sophisticated ways compared to earlier stages of development, where friendships were often based on convenience, such as proximity. At this stage, they choose friends based on specific characteristics, such as shared interests, shared values, or a similar sense of humor. They also start to realize that friendships come with both benefits and challenges. Additionally, they show greater concern for others and focus less on themselves. Through these friendships, children learn teamwork and develop a strong desire to be liked and accepted by their peers.^[67]

Friendships offer valuable opportunities to develop social skills, such as effective communication, negotiating, and resolving differences. Through peer interactions, children gain insights into various aspects of life, including how to perform tasks, gain popularity, choose what to wear, and navigate social norms. They also learn how to initiate and sustain relationships with others. Managing conflict becomes a key skill, as children practice taking turns, compromising, and bargaining. This socialization represents a significant shift from a family-centered focus to one increasingly influenced by peers.^[68]

Nurses teach parents and caregivers how to support their children in fostering healthy peer relationships and developing social skills with the following tips:

• Stay Engaged in Conversations: Encourage caregivers to ask open-ended questions about their child’s day, friends, and interactions to foster open communication. For example, “What was something fun you did with your friends today?”
• Model Social Skills: Caregivers can demonstrate positive social behaviors, such as active listening, sharing, and resolving conflicts respectfully.
• Help Navigate Challenges: Teach children strategies for handling peer pressure, conflicts, or misunderstandings, emphasizing the importance of kindness and standing up for themselves.
• Validate Emotions: Remind caregivers to listen and validate their child’s feelings about friendships without judgment, helping them process and learn from their experiences.

Language

By the time children enter kindergarten, they have mastered the foundational elements of language, including a broad vocabulary and basic grammatical rules. By fifth grade, their vocabulary expands to approximately 40,000 words, and they become increasingly skilled at expressing their thoughts and emotions. This growing sophistication is reflected in their enjoyment of telling jokes, especially simple jokes with punchlines or involving wordplay, such as “knock-knock” jokes.^[69]

Emotional Regulation

Children begin the school-aged years relatively dependent on their parents but grow increasingly autonomous as they approach adolescence, particularly in decision-making and self-care. At age eight, children may start to argue with their parents, but these disagreements are usually resolved through reasoning about family rules and expectations. With an understanding of right and wrong and the consequences of their actions, defiance is typically rare. However, as a child reaches age 12, their emotions become more intense and variable as their need for autonomy develops. They typically express their own desires and often test limits set by their parents.^[70]

Adolescent

Adolescence begins at puberty and ends in early adulthood, typically between the ages of 12 and 18. See Figure 13.9^[71] for an image of an adolescent. This stage of development is characterized by certain predictable milestones, but adolescence itself is a socially constructed concept. Markers that traditionally signal the end of adolescence, such as completing high school or becoming independent from one’s parents, have been occurring later in life in the United States. As a result, the length of adolescence has been extended.^[72]

Adolescence is a period of significant physical change, marked by a growth spurt and sexual maturation during puberty. It is also a time of cognitive development, as adolescents begin to think about abstract concepts such as love and freedom. During this stage, teens often develop a sense of invincibility, which can lead to risky behaviors, as they may feel that nothing bad can happen to them. Unfortunately, these risky behaviors can have lifelong consequences, such as contracting sexually transmitted infections or being involved in accidents that can result in chronic disability or death.^[73]

Physical Domain

Second only to infancy, adolescence is a period of rapid physical development. During this stage, adolescents gain about 50% of their adult body weight, become capable of sexual reproduction through puberty, and undergo significant brain changes.^[74]

Both boys and girls experience a growth spurt in height, the development of pubic and underarm hair, and skin changes that may lead to acne. Boys also develop facial hair and a deeper voice, while girls experience breast development and the onset of menstruation. These pubertal changes are driven by testosterone for boys and estrogen for girls.^[75]

Adolescents experience accelerated growth at different times, but it follows a predictable sequence. First, the head, hands, and feet grow, followed by the arms and legs, and then the torso and shoulders. This uneven growth can make their bodies appear out of proportion. Because physical development varies widely among teens, puberty can be a source of pride for some and embarrassment for others. Adolescents are highly aware of their body changes and strive to fit in, not wanting to stand out from their peers. Those who experience early puberty may be at higher risk for anxiety, depression, low self-esteem, or poor body image because they may feel self-conscious about appearing different.^[76],[77]

Movement and Motor Development

Prior to the adolescent growth spurt, boys and girls are generally similar in strength. However, after puberty, males typically become physically stronger than females due to increases in bone density and muscle mass. As their limbs lengthen, adolescents may experience clumsiness in their movements. However, as their brain adapts to these changes, this awkwardness usually resolves. Regular physical activity can help teens improve their strength and coordination.^[78]

Cognitive Domain

Biological changes in an adolescent’s brain structure, along with the strengthening of neural pathways, increased experience, knowledge, and evolving social demands, contribute to rapid cognitive growth. These changes typically begin at puberty or shortly thereafter, with some skills continuing to develop as the adolescent matures. The development of the prefrontal cortex, which controls and plans behavior, plays a key role in executive functioning.^[79]

Cognitive development during adolescence leads to significant advances in thinking. Adolescents become better at focusing on multiple ideas simultaneously and show improvements in focusing on more than one idea at the same time. They improve in their memory, processing speed, organization, and metacognition (thinking about their thinking). Metacognition enables them to plan ahead, consider the future consequences of their actions, and create alternatives. One of the key cognitive advances during this time is the ability to think abstractly and hypothetically, going beyond their direct experiences.^[80]

Research indicates that the limbic system, which is the part of the brain that perceives rewards from risks, becomes much more active in early adolescence. However, the frontal lobe, which controls impulses and allows for long-term thinking, matures later. This developmental imbalance may help explain why teens are more prone to taking risks. Most injuries sustained by adolescents are linked to risky behaviors, such as alcohol and drug use, reckless or distracted driving, and unprotected sex. Studies examining the cognitive and emotional processes underlying adolescent risk-taking suggest that teens often prioritize social rewards and friendships over potential consequences, which can significantly influence their decision-making.^[81]

Some theorists suggest there may be evolutionary benefits to adolescents’ increased propensity for risk-taking. From a population perspective, having individuals willing to try new methods and approaches provides an advantage by counterbalancing the traditional, conservative knowledge and practices maintained by older generations. Thus, adolescents’ risk-taking may help introduce fresh ideas and challenge the status quo.^[82]

As the frontal lobe develops in adolescents, several key changes. First, self-control improves, allowing adolescents to better assess the potential cause and effect of their actions. Changes in the levels of certain neurotransmitters (such as dopamine and serotonin) also influence the way in which adolescents experience emotions, typically making them more emotional and more sensitive to stress. These neurological changes may explain why many mental health disorders, such as schizophrenia, anxiety, depression, bipolar disorder, and eating disorders, tend to emerge during adolescence.^[83],[84]

Psychosocial Domain

Adolescents continue to refine their sense of self as they relate to others. According to Erikson’s theory of psychosocial development, this stage is characterized by the conflict of identity versus role confusion. Adolescents must navigate the complexities of forming their own identity, which contrasts with role confusion, where individuals lack a clear understanding of who they are as a person or where they fit in with society. This process is influenced by how earlier childhood psychosocial issues were resolved, creating a bridge between their past as children and their future as adults.^[85]

As adolescents work to form their identities, they begin to distance themselves from their parents, and their peer group becomes increasingly important. A key change during this time is the renegotiation of parent-child relationships. Some adolescents adopt values and roles based on parental beliefs and expectations, while others develop identities that align with a peer group, sometimes in opposition to their parents’ views. To develop a sense of self, adolescents explore, test limits, and make independent decisions, which renders parental monitoring for their safety increasingly important as they strive for autonomy.^[86]

Romantic relationships typically begin to emerge during adolescence. Same-sex peer groups, common in childhood, often expand into mixed-sex peer groups, creating a context where romantic relationships can form. Adolescents often devote significant time and emotional energy to romantic relationships, with their emotions—both positive and negative—frequently more shaped by these relationships (or lack thereof) than by friendships or family connections. The importance of romantic relationships during this developmental stage should not be underestimated, as they play a critical role in shaping adolescents’ identity, redefining family and peer dynamics, and exploring emerging sexuality.^[87]

Sexual Development

Healthy sexual development involves a combination of physical development, psychosocial interactions, and the formation of a positive sexual identity. Teens strive to become comfortable with their changing bodies and begin making decisions about which, if any, sexual activities they wish to engage in. Sexual development is shaped by a complex interaction of physical and cognitive changes, along with social expectations. As they mature physically, adolescents often compare their own characteristics to those of their peers or to idealized body images portrayed in the media, such as fashion models or athletes.^[88]

As sex hormones cause biological changes to occur in the reproductive system, they also trigger sexual thoughts. Sexual interest is a natural part of adolescence. Although cultural values, beliefs, and expectations influence sexual behaviors, peers are also very influential.^[89]

Many early romantic relationships begin with nonsexual interactions, such as messaging and phone calls. By age 12 or 13, some teens begin dating and experimenting with kissing, touching, and other sexual activities such as oral sex. Adolescents aged 14 to 16, when educated on the consequences of unprotected sex, sexually transmitted infections, and pregnancy, typically understand the risks. However, they may lack the ability to apply this knowledge in real-life peer situations or act responsibly in the heat of the moment. By age of 17, many adolescents report experiencing sexual intercourse, often influenced by peer pressure.^[90]

Becoming a sexually healthy adult is a developmental task of adolescence, requiring the integration of psychological, physical, cultural, spiritual, societal, and educational factors. Healthy adult relationships are more likely to develop when an adolescent’s sexual development is not shamed but instead acknowledged as a normal part of growth, accompanied by open communication and guidance regarding the risks of unintended pregnancies and sexually transmitted infections (STIs) from unprotected vaginal intercourse, as well as the risks of STIs from various forms of unprotected sex, such as anal and oral sex. Nurses can support adolescents by providing education on these topics, empowering them to make informed and healthy decisions regarding sexual activity.^[91]

Emotional Regulation

Emotionally, adolescents may seem rude, short-tempered, and moody as they navigate their evolving sense of identity. They may fluctuate between setting high expectations for themselves and experiencing self-doubt, which can contribute to anxiety, depression, or eating disorders. Some teens turn to chemical substances, such as alcohol or marijuana, to cope with their emotions. However, the use of these substances is risky as they can impair judgment and increase the likelihood of engaging in other dangerous behaviors, such as driving under the influence or participating in unprotected sexual activity.^[92]

In adolescence, a renewed egocentrism may emerge. For example, a teen with a small pimple on their face might perceive it as huge and highly noticeable, mistakenly believing that others share their critical perceptions about their appearance.^[93]

Moral Development

As adolescents gain more independence, their understanding of morality becomes more complex, and they begin to consider what is right or wrong in more nuanced ways. As their cognitive, emotional, and psychosocial development matures, adolescents expand their moral reasoning and apply these principles to their daily lives.^[94]

From middle childhood into early adolescence, the child begins to care about how situations impact others, and they want to please others and feel accepted (i.e., Kohlberg’s theory regarding conventional morality). Adolescents often begin to use abstract reasoning to justify behavior (i.e., Kohlberg’s theory regarding postconventional morality).^[95]

In terms of moral decision-making, younger children are heavily influenced by their family members, cultural beliefs, and religious traditions, while adolescents experience an increased influence from peers, as friendships become central to their lives. Furthermore, a teen’s ability to think abstractly allows them to recognize that rules and laws are created by society. They may begin questioning the absolute authority of parents, schools, government, and other traditional institutions. Adolescents also begin engaging in relativistic thinking, questioning others’ assertions and moving away from accepting information as absolute truth. They begin to differentiate between rules based on common sense (e.g., don’t touch a hot stove) and those crafted from cultural standards (e.g., following dress code standards in specific situations). This shift in thinking often leads to a period of questioning authority across various domains.^[96]

Nurses teach parents and caregivers how to support their teen through the various challenges of adolescence by offering emotional support, positive coping strategies, guidance, and understanding. Teaching topics include the following:

• Provide Emotional Support and Validation: Adolescence is a time of emotional ups and downs, so it’s important for caregivers to listen without judgment and validate their teen’s feelings. Offering reassurance and understanding helps teens navigate the stress of body changes, social pressures, and identity formation.
• Foster Open Communication: Create an environment where the teen feels comfortable talking about their thoughts, fears, and experiences. Open, non-judgmental conversations about puberty, relationships, and peer pressure can help teens feel more confident and less isolated.
• Model Healthy Body Image: Because body image is a significant concern during puberty, caregivers can model positive body image behaviors by focusing on health and self-acceptance rather than appearance. Encouraging physical activity and healthy eating habits can also promote physical well-being.
• Respect Their Growing Need for Independence: As teens seek more autonomy, caregivers can support their growing independence by giving them opportunities to make decisions, take on responsibilities, and solve problems on their own, while still providing guidance and boundaries.
• Help Manage Social Pressures: Adolescents may struggle with peer pressure, and caregivers can help by offering advice on handling situations involving alcohol, drugs, or unhealthy relationships. Encourage teens to make decisions based on their values rather than fitting in with the crowd.
• Provide Age-Appropriate Information Regarding Puberty: Caregivers should ensure that their teens have accurate information about puberty, sexuality, and relationships. Having honest conversations about these topics can prevent confusion and anxiety.
• Acknowledge the Impact of Puberty: Recognize that the physical, emotional, and cognitive changes teens experience can affect their self-esteem and behavior. Offering empathy during this period can make a big difference in how teens cope with their developing identity.
• Provide Chemical Substance Education: Educating adolescents about the risks of substance use and its effects on their physical and emotional health can help them make more informed decisions. Caregivers should also discuss the potential consequences of risky behaviors, such as impaired judgment leading to driving under the influence or unprotected sexual activity.
• Encourage Positive Activities: Helping adolescents engage in extracurricular activities, hobbies, or sports can provide a constructive outlet for their energy and emotions. These activities also promote self-esteem and a sense of belonging.
• Seek Professional Support: If an adolescent struggles with emotional challenges or substance use, caregivers should consider seeking help from a mental health professional or counselor. Therapy and support groups can offer additional tools for managing emotions and addressing risky behaviors.
• Set Clear Boundaries and Expectations: While fostering independence, caregivers should maintain consistent boundaries and rules regarding substance use and risky behaviors. Clear expectations, coupled with appropriate consequences, can help adolescents feel more secure and guided during this challenging period.
• Model Healthy Coping Mechanisms: By demonstrating positive ways to manage stress, anxiety, and emotions—such as exercise, mindfulness, or talking about feelings—caregivers can encourage adolescents to adopt these strategies themselves.

By creating a supportive, open, and understanding environment, and using a balanced approach of empathy, education, and guidance, caregivers can help teens navigate the complexities of puberty with confidence and resilience. This approach also enables caregivers to assist adolescents in managing the emotional and developmental challenges of this stage while minimizing the risks associated with substance use and other harmful behaviors.

Informed Consent for Adolescents

Nurses and health care providers are legally and ethically bound to ensure informed consent is provided to clients, including the risks, benefits, and options for medical care. State laws regarding informed consent for minors under age 18 vary. Generally, health care providers cannot treat a minor without the consent of the minor’s parent or guardian, but exceptions exist regarding treatment related to sexually transmitted infections, pregnancy, or contraception. In some states, minors can receive confidential medical care without parental consent, encouraging them to seek help they might otherwise avoid if they had to tell their parents. Privacy issues may arise when parents receive an explanation of benefits form from their insurance company disclosing who obtained care and the diagnostic tests or procedures provided. Ethically, nurses and health care providers must balance respecting the autonomy of adolescent clients with ensuring their ability to understand and make informed decisions.^{[97],[98],[99]}

When appropriate, adolescent clients should be given the opportunity to have private time during appointments with a health care provider, without their parents or caregivers present, to facilitate open discussion of relevant health history and preventive care. Providers build trust with their teen clients by honoring confidentiality while also adhering to state law. However, health care providers and nurses should also encourage adolescents to discuss health matters with their parents or caregivers even if they feel the conversation may be uncomfortable.^[100],[101]

Nurses must be aware of the state laws regarding treatment for minors in the states where they practice. Below is a summary of key considerations regarding informed consent for minors in various medical circumstances:

• Electronic Medical Record: In some states, specific parts of a minor’s online medical record are restricted from parental access unless the child provides consent.
• Vaccines: Parents may choose to offer or refuse vaccines for their children. However, some states allow adolescents to consent to certain vaccines, such as human papillomavirus (HPV) vaccine, even if parents refuse.^[102]
• Prenatal Care: Most states permit minors to obtain confidential prenatal care, recognizing its importance for a healthy pregnancy and the birth of a healthy infant. Some states allow providers to inform parents if it is deemed to be in the minor’s best interest.^[103]
• Abortion: Abortion remains a controversial issue, and most states require minors to involve a parent or guardian before the procedure.^[104]
• Alcohol Treatment: In some states, minors aged 12 and older can consent to outpatient treatment for alcohol or other drugs without parental consent, and providers are not required to notify parents.
• Mental Health: Many states grant minors aged 12-18 the right to provide consent for mental health treatment, and they may also protest involuntary admission unless they pose a risk to themselves or others. In such cases, a neutral mental health review officer is appointed to ensure the minor’s rights are upheld.^[105]