Principles of Human Growth and Development

Development: Is the pattern of progressive, orderly and predictable changes that begins at conception and continues throughout life.

Growth: Is an increase in the size and number of human cells as they develop.

Maturation: Is the process by which an individual grows and develop throughout life. 

The principle of human growth and development include;

1. Development is Continuous: The process of growth and development continues from the conception till the individual reaches maturity. Development of both physical and mental traits continues gradually until these traits reach their maximum growth. It goes on continuously throughout life. Even after maturity has been attained, development does not end.

2. Development is Gradual: It does not come all on a sudden.

3. Development is Sequential: Development is sequential or orderly. Every individual follows a pattern of development peculiar to it. A child crawls before he creeps, stands before he walks and babbles before he talks.

4. Rate of Development Varies Person to Person: Rate of development is not uniform. Individuals differ in the rate of growth and development. Boys and girls have different development rates. Each part of the body has its own particular rate of growth. 

5. Development Proceeds from General to Specific: Development proceeds from general to specific. In all areas of development, general activity always precedes specific activity. For example, the fetus moves its whole body but is incapable of making specific responses. With respect to emotional behavior infants approach strange and unusual objects with some sort of general fear response. Later, their fears become more specific and elicit different kinds of behavior, such as, crying, turning away and hiding etc.

6. Most Traits are correlated in Development: Generally, it is seen that the child whose mental development is above average, is also superior in so many other aspects like health, sociability and special aptitudes.

7. Growth and Development is a Product of Both Heredity and Environment: Development is influenced by both heredity and environment. Both are responsible for human growth and development.

8. Development is Predictable: Growth can be predicated by observation and psychological tests.

9. Development brings about both structural and functional changes.

10. There is a Constant Interaction between All Factors of Development: Development in one area is highly related to development in other areas. For example, a child who has a good health can be active socially and intellectually,

Stages of Growth and Child Development (Jean Piaget, Lev Vygotsky, Lawrence Kohlberg, and Erik Erikson)

There are three broad stages of development: early childhood, middle childhood, and adolescence. 

1. 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.

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.

Over the first three years of life, children develop a spoken vocabulary. 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-year old still reasons in concrete ways and have difficulty understanding abstract ideas.

2. 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.

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. 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. 

3. Adolescence (Twelve to Eighteen Years)

Adolescence can be defined as the temporary period of physical and psychological development between childhood and adulthood.

Jean Piaget describes adolescence as the stage of life in which the individual’s thoughts start taking more of an abstract form and egocentric thoughts decrease. This allows the adolescent to think and reason with a wider perspective

The adolescent years are another period of accelerated growth. 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).With so  many intense experiences, adolescence is also an important time in emotional development. Mood swings are a characteristic of adolescence. The onset of many psychological disorders, such as depression, other mood disorders, and schizophrenia, is also common at this time of life.

Puberty

This is the period during which a person first becomes capable of sexual reproduction.

Physical Changes of Puberty: Puberty is the period of several years in which rapid physical growth and psychological changes occur. The onset of puberty typically occurs at age 10 or 11 for females and at age 11 or 12 for males; females usually complete puberty by ages 15 to 17, while males usually finish around ages 16 to 17. Females tend to attain reproductive maturity about four years after the first physical changes of puberty appear. Males, however, accelerate more slowly but continue to grow for about six years after the first visible pubertal changes. While the sequence of physical changes in puberty is predictable, the onset and pace of puberty vary widely. Every person’s individual timetable for puberty is different and is primarily influenced by heredity; however environmental factors such as diet and exercise also exert some influence.

Hormonal Changes: Puberty involves distinctive physiological changes in an individual’s height, weight, body composition, and circulatory and respiratory systems. During this time, both the adrenal glands and the sex glands mature processes known as adrenarche and gonadarche, respectively.

These changes are largely influenced by hormonal activity. Hormones play an organizational role

(Priming the body to behave in a certain way once puberty begins) and an activation role (triggering certain behavioral and physical changes). During puberty, the adolescent’s hormonal balance shifts strongly towards an adult state; the process is triggered by the pituitary gland, which secretes a surge of hormonal agents into the blood stream and initiates a chain reaction.

Sexual Maturation

It is this stage in life in which a child develops secondary sex characteristics. Primary sex characteristics are organs specifically needed for reproduction, like the uterus and ovaries in females and the testes in males. Secondary sex characteristics, on the other hand, are physical signs of sexual maturation that do not directly involve sex organs. In females, this includes development of breasts and widening of hips, while in males it includes development of facial hair and deepening of the voice. Both sexes experience development of pubic and underarm hair, as well as increased development of sweat glands.

The male and female gonads are activated by the surge of hormones, which puts them into a state of rapid growth and development. The testes primarily release testosterone, and the ovaries release estrogen; the production of these hormones increases gradually until sexual maturation is met. Girls experience menarche, the beginning of menstrual periods, usually around 12–13 years old, and boys experience spermarche, the first ejaculation, around 13–14 years old. Facial hair in males typically appears around age 14.

Physical Growth

The adolescent growth spurt is a rapid increase in an individual’s height and weight during puberty resulting from the simultaneous release of growth hormones, thyroid hormones, and androgens. Males experience their growth spurt about two years later than females. The accelerated growth in different body parts happens at different times, but for all adolescents it has a fairly regular sequence. The first places to grow are the extremities (head, hands, and feet), followed by the arms and legs, and later the torso and shoulders. This non-uniform growth is one reason why an adolescent body may seem out of proportion. During puberty, bones become harder and more brittle.

Before puberty, there are nearly no differences between males and females in the distribution of fat and muscle. During puberty, males grow muscle much faster than females, and females experience a higher increase in body fat. An adolescent’s heart and lungs increase in both size and capacity during puberty; these changes contribute to increased strength and tolerance for exercise.

Brain Development

The adolescent brain also remains under development during this time. Adolescents often engage in increased risk-taking behaviors and experience heightened emotions during puberty; this may be due to the fact that the frontal lobes of their brains—which are responsible for judgment, impulse control, and planning—are still maturing until early adulthood (Casey, Tottenham, Liston, & Durston).