Definitions of stages of growth in childhood come from many sources. Theorists such as Jean Piaget, Lev Vygotsky, Lawrence Kohlberg, and Erik Erikson have provided ways to understand development, and recent research has provided important information regarding the nature of development. In addition, stages of childhood are defined culturally by the social institutions, customs, and laws that make up a society. For example, while researchers and professionals usually define the period of early childhood as birth to eight years of age, others in the United States might consider age five a better end point because it coincides with entry into the cultural practice of formal schooling.
There are three broad stages of development: early childhood, middle childhood, and adolescence. The definitions of these stages are organized around the primary tasks of development in each stage, though the boundaries of these stages are malleable. Society's ideas about childhood shift over time, and research has led to new understandings of the development that takes place in each stage.
Early Childhood (Birth to Eight Years)
Early childhood is a time of tremendous growth across all areas of development. The dependent newborn grows into a young person who can take care of his or her own body and interact effectively with others. For these reasons, the primary developmental task of this stage is skill development.
Physically, between birth and age three a child typically doubles in height and quadruples in weight. Bodily proportions also shift, so that the infant, whose head accounts for almost one-fourth of total body length, becomes a toddler with a more balanced, adult-like appearance. Despite these rapid physical changes, the typical three-year-old has mastered many skills, including sitting, walking, toilet training, using a spoon, scribbling, and sufficient hand-eye coordination to catch and throw a ball.
Between three and five years of age, children continue to grow rapidly and begin to develop fine-motor skills. By age five most children demonstrate fairly good control of pencils, crayons, and scissors. Gross motor accomplishments may include the ability to skip and balance on one foot. Physical growth slows down between five and eight years of age, while body proportions and motor skills become more refined.
Physical changes in early childhood are accompanied by rapid changes in the child's cognitive and language development. From the moment they are born, children use all their senses to attend to their environment, and they begin to develop a sense of cause and effect from their actions and the responses of caregivers.
Over the first three years of life, children develop a spoken vocabulary of between 300 and 1,000 words, and they are able to use language to learn about and describe the world around them. By age five, a child's vocabulary will grow to approximately 1,500 words. Five-year-olds are also able to produce five-to seven-word sentences, learn to use the past tense, and tell familiar stories using pictures as cues.
Language is a powerful tool to enhance cognitive development. Using language allows the child to communicate with others and solve problems. By age eight, children are able to demonstrate some basic understanding of less concrete concepts, including time and money. However, the eight-yearold still reasons in concrete ways and has difficulty understanding abstract ideas.
A key moment in early childhood socioemotional development occurs around one year of age. This is the time when attachment formation becomes critical. Attachment theory suggests that individual differences in later life functioning and personality are shaped by a child's early experiences with their caregivers. The quality of emotional attachment, or lack of attachment, formed early in life may serve as a model for later relationships.
From ages three to five, growth in socioemotional skills includes the formation of peer relationships, gender identification, and the development of a sense of right and wrong. Taking the perspective of another individual is difficult for young children, and events are often interpreted in all-or-nothing terms, with the impact on the child being the fore-most concern. For example, at age five a child may expect others to share their possessions freely but still be extremely possessive of a favorite toy. This creates no conflict of conscience, because fairness is determined relative to the child's own interests. Between ages five and eight, children enter into a broader peer context and develop enduring friendships. Social comparison is heightened at this time, and taking other people's perspective begins to play a role in how children relate to people, including peers.
Implications for in-school learning. The time from birth to eight years is a critical period in the development of many foundational skills in all areas of development. Increased awareness of, and ability to detect, developmental delays in very young children has led to the creation of early intervention services that can reduce the need for special education placements when children reach school age. For example, earlier detection of hearing deficits sometimes leads to correction of problems before serious language impairments occur. Also, developmental delays caused by premature birth can be addressed through appropriate therapies to help children function at the level of their typically developing peers before they begin school.
An increased emphasis on early learning has also created pressure to prepare young children to enter school with as many prerequisite skills as possible. In 1994 federal legislation was passed in the United States creating Goals 2000, the first of which states that "All children will enter school ready to learn" (U.S. Department of Education, 1998). While the validity of this goal has been debated, the consequences have already been felt. One consequence is the use of standardized readiness assessments to determine class placement or retention in kindergarten. Another is the creation of transition classes (an extra year of schooling before either kindergarten or first grade). Finally, the increased attention on early childhood has led to renewed interest in preschool programs as a means to narrow the readiness gap between children whose families can provide quality early learning environments for them and those whose families cannot.
Middle Childhood (Eight to Twelve Years)
Historically, middle childhood has not been considered an important stage in human development. Sigmund Freud's psychoanalytic theory labeled this period of life the latency stage, a time when sexual and aggressive urges are repressed. Freud suggested that no significant contributions to personality development were made during this period. However, more recent theorists have recognized the importance of middle childhood for the development of cognitive skills, personality, motivation, and inter-personal relationships. During middle childhood children learn the values of their societies. Thus, the primary developmental task of middle childhood could be called integration, both in terms of development within the individual and of the individual within the social context.
Perhaps supporting the image of middle childhood as a latency stage, physical development during middle childhood is less dramatic than in early childhood or adolescence. Growth is slow and steady until the onset of puberty, when individuals begin to develop at a much quicker pace. The age at which individuals enter puberty varies, but there is evidence of a secular trend–the age at which puberty begins has been decreasing over time. In some individuals, puberty may start as early as age eight or nine. Onset of puberty differs across gender and begins earlier in females.
As with physical development, the cognitive development of middle childhood is slow and steady. Children in this stage are building upon skills gained in early childhood and preparing for the next phase of their cognitive development. Children's reasoning is very rule based. Children are learning skills such as classification and forming hypotheses. While they are cognitively more mature now than a few years ago, children in this stage still require concrete, hands-on learning activities. Middle childhood is a time when children can gain enthusiasm for learning and work, for achievement can become a motivating factor as children work toward building competence and self-esteem.
Middle childhood is also a time when children develop competence in interpersonal and social relationships. Children have a growing peer orientation, yet they are strongly influenced by their family. The social skills learned through peer and family relationships, and children's increasing ability to participate in meaningful interpersonal communication, provide a necessary foundation for the challenges of adolescence. Best friends are important at this age, and the skills gained in these relationships may provide the building blocks for healthy adult relationships.
Implications for in-school learning. For many children, middle childhood is a joyful time of increased independence, broader friendships, and developing interests, such as sports, art, or music. However, a widely recognized shift in school performance begins for many children in third or fourth grade (age eight or nine). The skills required for academic success become more complex. Those students who successfully meet the academic challenges during this period go on to do well, while those who fail to build the necessary skills may fall further behind in later grades.
Recent social trends, including the increased prevalence of school violence, eating disorders, drug use, and depression, affect many upper elementary school students. Thus, there is more pressure on schools to recognize problems in eight-to eleven-year-olds, and to teach children the social and life skills that will help them continue to develop into healthy adolescents.
Adolescence (Twelve to Eighteen Years)
Adolescence can be defined in a variety of ways: physiologically, culturally, cognitively; each way suggests a slightly different definition. For the purpose of this discussion adolescence is defined as a culturally constructed period that generally begins as individuals reach sexual maturity and ends when the individual has established an identity as an adult within his or her social context. In many cultures adolescence may not exist, or may be very short, because the attainment of sexual maturity coincides with entry into the adult world. In the current culture of the United States, however, adolescence may last well into the early twenties. The primary developmental task of adolescence is identity formation.
The adolescent years are another period of accelerated growth. Individuals can grow up to four inches and gain eight to ten pounds per year. This growth spurt is most often characterized by two years of fast growth, followed by three or more years of slow, steady growth. By the end of adolescence, individuals may gain a total of seven to nine inches in height and as much as forty or fifty pounds in weight. The timing of this growth spurt is not highly predictable; it varies across both individuals and gender. In general, females begin to develop earlier than do males.
Sexual maturation is one of the most significant developments during this time. Like physical development, there is significant variability in the age at which individuals attain sexual maturity. Females tend to mature at about age thirteen, and males at about fifteen. Development during this period is governed by the pituitary gland through the release of the hormones testosterone (males) and estrogen (females). There has been increasing evidence of a trend toward earlier sexual development in developed countries–the average age at which females reach menarche dropped three to four months every ten years between 1900 and 2000.
Adolescence is an important period for cognitive development as well, as it marks a transition in the way in which individuals think and reason about problems and ideas. In early adolescence, individuals can classify and order objects, reverse processes, think logically about concrete objects, and consider more than one perspective at a time. However, at this level of development, adolescents benefit more from direct experiences than from abstract ideas and principles. As adolescents develop more complex cognitive skills, they gain the ability to solve more abstract and hypothetical problems. Elements of this type of thinking may include an increased ability to think in hypothetical ways about abstract ideas, the ability to generate and test hypotheses systematically, the ability to think and plan about the future, and meta-cognition (the ability to reflect on one's thoughts).
As individuals enter adolescence, they are confronted by a diverse number of changes all at one time. Not only are they undergoing significant physical and cognitive growth, but they are also encountering new situations, responsibilities, and people.
Entry into middle school and high school thrusts students into environments with many new people, responsibilities, and expectations. While this transition can be frightening, it also represents an exciting step toward independence. Adolescents are trying on new roles, new ways of thinking and behaving, and they are exploring different ideas and values. Erikson addresses the search for identity and independence in his framework of life-span development. Adolescence is characterized by a conflict between identity and role confusion. During this period, individuals evolve their own self-concepts within the peer context. In their attempts to become more independent adolescents often rely on their peer group for direction regarding what is normal and accepted. They begin to pull away from reliance on their family as a source of identity and may encounter conflicts between their family and their growing peer-group affiliation.
With so many intense experiences, adolescence is also an important time in emotional development. Mood swings are a characteristic of adolescence. While often attributed to hormones, mood swings can also be understood as a logical reaction to the social, physical, and cognitive changes facing adolescents, and there is often a struggle with issues of self-esteem. As individuals search for identity, they confront the challenge of matching who they want to become with what is socially desirable. In this context, adolescents often exhibit bizarre and/or contradictory behaviors. The search for identity, the concern adolescents have about whether they are normal, and variable moods and low self-esteem all work together to produce wildly fluctuating behavior.
The impact of the media and societal expectations on adolescent development has been farreaching. Young people are bombarded by images of violence, sex, and unattainable standards of beauty. This exposure, combined with the social, emotional, and physical changes facing adolescents, has contributed to an increase in school violence, teen sexuality, and eating disorders. The onset of many psychological disorders, such as depression, other mood disorders, and schizophrenia, is also common at this time of life.
Implications for in-school learning. The implications of development during this period for education are numerous. Teachers must be aware of the shifts in cognitive development that are occurring and provide appropriate learning opportunities to support individual students and facilitate growth. Teachers must also be aware of the challenges facing their students in order to identify and help to correct problems if they arise. Teachers often play an important role in identifying behaviors that could become problematic, and they can be mentors to students in need.
The definitions of the three stages of development are based on both research and cultural influences. Implications for schooling are drawn from what is known about how children develop, but it should be emphasized that growth is influenced by context, and schooling is a primary context of childhood. Just as educators and others should be aware of the ways in which a five-year-old's reasoning is different from a fifteen-year-old's, it is also important to be aware that the structure and expectations of schooling influence the ways in which children grow and learn.
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