Growth and Development of Human Beings

The Growth and Development of Humans

Development means "a progressive series of changes that occur in an orderly predictable pattern as a result of maturation and experience." Developmental psychology is concerned with the scientific understanding of age-related changes in experience and behavior processes from conception to death.

Developmental psychologists aim to explain how thinking, feeling, and behavior change throughout life. This field examines evolution across three major dimensions: physical development, cognitive development, and socioemotional development. Within these three dimensions are a broad range of topics, including motor skills, executive functions, moral understanding, language acquisition, social change, personality, emotional development, self-concept, and identity formation.

Developmental psychology also examines the influences of nature and nurture on the process of human development and operations of change.

People undergo many physical, cognitive, social, intellectual, and emotional changes throughout life. Developmental psychology theories tend to explain development in terms of progression through life stages.

In this section, we will look at how individuals typically grow and develop.

Developmentalists break the life span into ten stages as follows:

Prenatal Development

Infancy 0-1yr

Toddlerhood 1-3yr

Early Childhood 3-5yrs

Middle Childhood 6-12yrs

Adolescence 12-21yrs

Early Adulthood 21-35yrs

Mature Adulthood 36-56yrs

Older Adulthood 57-77yrs

Elder Adulthood 78yrs and Up

This list reflects unique aspects of the various stages of childhood and adulthood that will be explored in this article. So while both an 8-month-old and an 8-year-old are considered children, they have very different motor abilities, social relationships, and cognitive skills. Their nutritional needs are different, and their primary psychological concerns are also distinctive. The same is true of an 28-year-old and an 80-year-old, both are considered adults. We will discover the distinctions between being 28 or 48 as well. But first, here is a brief overview of the stages.

The following are the stages of development:

Prenatal Development

Conception occurs, and development begins. All of the body's significant structures are forming, and the mother's health is of primary concern. Understanding nutrition, environmental factors, and labor and delivery are primary concerns.

Infancy 0-1 yr

This period extends from birth to 1 year of age. The infant who comes to the new environment, from the mother's womb, mainly needs nourishment.

During this stage, children grow from babies to toddlers. The most significant development that happens for babies is that they make their earliest connections with others. Also:

  •  they learn the first aspects of language

  •  they learn to crawl and possibly walk

  •  they become familiar with their environment


The majority of a newborn infant's time is spent in sleep. At first, this sleep is evenly spread throughout the day and night, but infants generally become night time sleepers after a couple of months.

Infants can be seen to have six states, grouped into pairs:

  • quiet sleep and active sleep (dreaming, when REM sleep occurs)

  • quiet waking, and active waking

  • fussing and crying   


Infant Perception

Infant perception is what a newborn can see, hear, smell, taste, and touch. These five features are better known as one's "five senses." Infants respond to stimuli differently in these different states.

Vision is significantly worse in infants than in older children. Infant sight tends to be blurry in the early stages but improves over time. Color perception similar to that seen in adults has been demonstrated in infants as young as four months,

Hearing is well-developed before birth, unlike vision.  Infants are relatively good at detecting the direction a sound comes from, and by 18 months, their hearing ability is approximately equal to an adult's.

Smell and taste are present, with infants showing different expressions of disgust or pleasure when presented with pleasant odors (honey, milk, etc.) or unpleasant odors (rotten egg) and tastes (e.g., sour taste). Newborns are born with odor and taste preferences acquired in the womb. 

Touch and feel are one of the better-developed senses at birth, considering it's one of the first senses to develop inside the womb.

Pain: Infants feel pain similarly, if not more strongly than older children, but pain-relief in infants has not received so much attention as an area of research. Glucose is known to relieve pain in newborns.

Toddlerhood 1-3 yrs

Infants shift between the ages of one and two to a developmental stage known as toddlerhood.  In this stage, an infant's transition into toddlerhood is highlighted through self-awareness, developing maturity in language use, and the presence of memory and imagination.  During this phase, children typically develop new skills and learn how to tell right from wrong.  They are no longer content to sit and watch; they want to move around and explore their environment. 

During toddlerhood, babies begin learning how to walk, talk, and make decisions for themselves. An essential characteristic of this age period is the development of language. Children learn how to communicate and express their emotions and desires through the use of vocal sounds, babbling, and, eventually, words.  Self-control also begins to develop. At this age, children take the initiative to explore, experiment and learn from making mistakes.

Toddlers also begin to identify themselves in gender roles, acting according to their perception of what a man or woman should do.

Early Childhood ages 3–5

The preschool stage is characterized by mimicry of adults and exploration of the world through play. Conflict with parents is typically resolved through the process of social role identification.

In their expanded world, children in the 3-5 age group attempt to find their way.

As a three to five-year-old, the child is busy learning the language, is gaining a sense of self and greater independence and is beginning to understand the workings of the physical world.

In the earliest years, children are "completely dependent on the care of others." Therefore, they develop a "social relationship" with their caregivers and, later, with family members. During their preschool years (3-5), they "enlarge their social horizons" to include people outside the family.

The motor skills of preschoolers increase so they can do more things for themselves. They become more independent. No longer entirely dependent on the care of others, the world of this age group expands. More people have a role in shaping their personalities. Preschoolers explore and question their world.

Play is a significant activity for ages 3–5. Through play, a child reaches higher levels of cognitive development.


Middle Childhood 5-12 yrs

In all cultures, middle childhood is a time for developing "skills that will be needed in their society."  School offers an arena in which children can gain a view of themselves as "industrious (and worthy)."  They can also develop industry outside of school in sports, games, and doing volunteer work. Children who achieve "success in school or games might develop a feeling of competence."

The middle childhood stage (6-12), also known as the latency stage, is a highly social stage.

During this period, the child develops a greater attention span, needs less sleep, and gains rapidly in strength; therefore, the child can expend much more effort to acquire skills and needs accomplishment, regardless of ability.

Once children begin school, their lives change considerably. They experience extensive physical, social, and mental growth. Middle childhood is marked by increased independence from the family and increased focus on school, friends, and independent recreational activities. Socially, children develop a clearer understanding of their place in the world. They can describe their experiences, thoughts, and feelings, and they want to be liked and accepted by friends, classmates, and teammates.

Adolescence 12-21 yrs


Adolescence is a period of dramatic physical change marked by an overall physical growth spurt and sexual maturation, known as puberty. It is also a time of cognitive change as the adolescent begins to think of new possibilities and consider abstract concepts such as love, fear, and freedom.

These changes have enormous implications for the individual's sexual, social, emotional, and vocational life.

These changes make the individual find an identity, which means developing an understanding of self, the goals one wishes to achieve, and the work/occupation role. The individual craves for encouragement and support of caretakers and peer groups. If he is successful, he will develop a sense of self or identity; otherwise, he will suffer from role confusion/ identity confusion.

Individuals develop an increasingly unique sense of "self" during this period. They often believe that their thoughts and ideas are distinctive and not understood by others. Interests, skills, academic performance, self-confidence, aptitudes, personal likes, and dislikes all serve to create an increasingly unique identity.

In early adolescence, some young people face the realization that their parents are not perfect, and they may respond with rudeness and challenges to parental authority. Towards the end of adolescence, these characteristics begin to change. The young person can see various points of view, can compromise, and can examine personal experiences.

In the adolescence stage, individuals are moving towards meaningful relationships, employment, and disengagement from family. In early adolescence, friendships often take the form of group peer relationships such as cliques, clubs, or teams. In later adolescence, individuals begin to think more about the future; they contemplate romantic relationships, work options, and moving away from home. For many young people, graduation from school marks the beginning of what can be a difficult "transition" period from adolescence to adulthood.

Early Adulthood 22-35 yrs


The twenties and thirties are often thought of as early adulthood. It is a time of focusing on the future and putting a lot of energy into making choices that will help one earn a full adult's status in the eyes of others. Love and work are the primary concerns at this stage of life.

As an adult, the individual takes a firmer place in society, usually holding a job, contributing to the community, and maintaining a family and care of offspring. These new responsibilities can create tensions and frustrations, and one solution involves an intimate relationship with the family.

If these problems are solved effectively by the love, affection, and support of family, the individual leads a healthy life; otherwise, he will develop a feeling of alienation and isolation, which negatively affects his personality.

Mature Adulthood 36-56 yrs

The late thirties through the mid-fifties is referred to as middle adulthood. This is when aging that began earlier becomes more noticeable and a period at which many people are at their peak of productivity in love and work. It may be a period of gaining expertise in specific fields and understanding problems, and finding solutions with greater efficiency than before. It can also be a time of becoming more realistic about possibilities in life, recognizing the difference between what is possible and what is likely.

This stage of life requires expanding one's interests beyond one's self to include the next generation.

This response reflects a desire for the wellbeing of humanity rather than selfishness. If this goal is not achieved, the individual will be disappointed and experience a feeling of stagnation.

Mature adulthood (36-56) is most often marked by a dedication to career, work, and family. Some individuals may find it challenging to maintain a sense of purpose during life transitions, such as retirement or children moving out.

Older Adulthood 57-77yrs

This life span period has increased in the last 100 years, particularly in industrialized countries; the young-old are very similar to midlife adults; still working, still relatively healthy, and always productive and active. The "old" remain productive and energetic, and the majority continues to live independently.  Issues of housing, healthcare, and extending active life expectancy are only a few of the topics of concern for this age group.

It is typical in our society for older adults to retire. Often this is seen as a time to rest and reflect on the accomplishments of life.

Elder Adulthood 78+yrs

The World Health Organization finds "no general agreement on the age at which a person becomes old." Most "developed countries" set the age as 70 or 75. However, in developing countries inability to make an "active contribution" to society, not chronological age, marks the beginning of old age.

Physically, older people experience a decline in muscular strength, reaction time, stamina, hearing, distance perception, and the sense of smell. They also are more susceptible to diseases such as cancer and pneumonia due to a weakened immune system.

Sexual expression depends in large part upon the emotional and physical health of the individual. Many older adults continue to be sexually active and satisfied with their sexual activity.

Mental disintegration may also occur, leading to dementia or ailments such as Alzheimer's disease. Studies show that perceptual speed, inductive reasoning, and spatial orientation decline.

During the final stage (78-end of life), people tend to reflect on life and begin to make peace with the idea of death. Some may develop a sense of integrity as they look back, but others may get "stuck" on specific experiences and failures and feel a sense of despair.