THEORIES OF GROWTH AND DEVELOPMENT: CONCEPTION THROUGH TO LATE CHILDHOOD

Chapter 15 THEORIES OF GROWTH AND DEVELOPMENT: CONCEPTION THROUGH TO LATE CHILDHOOD




KEY TERMS/CONCEPTS
























Nurses care for people who are in different stages of development. A basic understanding of growth and development enables the nurse to recognise the needs of each individual and, thus, to provide appropriate care. Human growth and development are orderly processes that begin at conception and continue until death. Every person progresses through definite phases of growth and development, but the rate and behaviours of this progression vary with each individual.


Every person is a unique individual and, while growth and development are generally categorised into age stages or by using terms describing the features of an age group, categorisation does not take into account individual differences. It does, however, provide a means of describing the characteristics associated with most individuals at stages when comparative developmental changes appear. Growth and development affect the whole person and, although defined separately, overlap and are dependent on each other.


Physical growth results as cells repeatedly divide then synthesise new components, causing an increase in the number and size of cells and, consequently, an increase in the size and weight of the body or any of its parts. Growth can be measured in height and mass or by the changes in physical appearance and body functions that occur as a person grows older.


Development refers to the behavioural aspects of a person’s progressive adaptation to their environment and is related to changes in psychological and social functioning.


Maturation is the process of attaining complete development and is the unfolding of full physical, emotional and intellectual capabilities. The term maturation is generally used to describe an increase in complexity that enables a person to function at a higher level.


A person’s development encompasses a range of dimensions besides the physical, for example, emotional and moral development. There are several theories, or approaches, regarding growth and development of these different dimensions. This chapter discusses these approaches and their implications for nursing practice.



THEORIES OF DEVELOPMENT


Some theories view development as a continuous process that moves from the simple to the complex, while other theories view development as a process characterised by alternating periods of equilibrium and change. The various developmental theories differ in how the human being is viewed. The following section of this chapter provides the reader with an introduction to the major theories, or approaches, which are psychoanalytical, cognitive–developmental, maturational, social learning and moral. It is not the intent of this section to provide the reader with an in-depth analysis of these theories, rather to provide an overview of each approach. It is expected that the reader will consult further texts, such as Sigelman (2003) if more information is required.



FREUD’S THEORY


Sigmund Freud (1856–1939) founded the psychoanalytical approach to, or theory of, development. Freud’s theory stresses the formative years of childhood as the basis for later psychoneurotic disorders, primarily through the unconscious repression of instinctual drives and sexual desires. His theory emphasises the drives of sex and aggression, which he saw as motivating much human behaviour.


According to Freud, an individual’s personality is composed of the ‘id’, the ‘ego’ and the ‘superego’ (Sigelman 2003). The id is that part of the psyche that is the source of instinctive energy, impulses and drives. Based on the pleasure principle, it directs behaviour towards self-gratification. The ego represents the conscious self and is that part of the psyche that maintains conscious contact with reality and tempers the primitive drives of the id and the demands of the superego with the physical and social needs of society. The superego is the individual’s conscience, which is formed as the result of internalisation of societal demands and restrictions (Carel 2006).


Freud’s theory of development is based on a series of psychosexual stages through which a person must pass. Successful completion of each stage is necessary before the next stage can be entered without detrimental effects on future development. According to Freud, specific body areas are the primary sites for expression and achievement of needs, and these sites change from stage to stage. Table 15.1 outlines the stages of development according to Freud’s theory.


TABLE 15.1 Developmental stages according to Freud



























Stage Age Behaviours
Oral 0–18 months
Anal 1–3 years



Phallic 3–6 years





Latency 6–12 years



Genital 12 years–adult








PIAGET’S THEORY


The theory of cognitive development focuses on the gradual development of cognitive processes, such as problem solving, and on the gradual development of intellectual growth. Cognitive development is the process by which a child becomes an intelligent person, acquiring knowledge and the ability to think, learn, reason and abstract.


Jean Piaget’s (1952) theory of cognitive development, which deals only with cognition and does not take into account all psychosocial aspects of the personality, views development as gradual, progressive and related to age. Piaget’s views are that, for learning to occur, a variety of new experiences or stimuli must exist. He believed that there are four major stages in the development of logical thinking, and that each stage builds on the accomplishments of the previous stage. Table 15.3 outlines Piaget’s stages of cognitive development (Huitt & Hummel 2003).


TABLE 15.3 Piaget’s stages of cognitive development























Stage Age Intellectual development
Sensorimotor Birth–2 years This stage of intellectual development is governed by sensations in which simple learning takes place. Problem solving is primarily trial and error, as the child progresses from reflex activity, through repetitive behaviours, to imitative behaviour. The child gradually acquires a sense that external objects have a separate and independent existence and that they exist even when they are not visible to them
Preoperational 2–7 years During this stage the predominant characteristic is egocentricity, wherein the child considers their own viewpoint as the only one possible. Thinking is concrete and tangible and the child lacks the ability to make deductions or generalisations. Problem solving does not usually follow logical thought processes
Concrete operational 7–11 years Thought becomes increasingly logical, and problems are solved in a systematic fashion. The child is able to consider points of view other than their own. Towards the end of this stage, the child demonstrates a greater reasoning ability
Formal operational >11 years Thinking is characterised by logical reasoning. The adolescent is able to think in abstract terms, draw logical conclusions and solve problems


GROWTH AND DEVELOPMENT


Growth and development are interrelated processes that are influenced by a variety of factors. The theoretical approaches outlined in this chapter, together with various other approaches, provide a framework for understanding the complexities of growth and development. Each approach emphasises different aspects of development; for example, cognitive developmentalists concentrate primarily on intellectual development, psychoanalytical theorists emphasise social and personality development, while maturational theorists focus primarily on physical growth and development (Santrock 2007).


It is important for the nurse to understand that childhood incorporates unique phases of development, and that these phases are accompanied by special needs. To care for individuals from infancy to adolescence, the nurse first requires knowledge of normal growth and development. By understanding what is normal, the nurse is more able to recognise departures from normal and, therefore, to plan and implement appropriate nursing actions.


Growth and development affect the total person and, although separately defined, growth and development overlap and are interdependent. Both occur from the moment of fertilisation until death. Growth in weight (mass) and height is variable and not uniform throughout life. The maximum rate of growth occurs before birth, in the 4th month of fetal life. Growth in height stops when maturation of the skeleton is complete. Standard growth charts are available on which measurements of growth may be periodically plotted and compared with the norm for that particular age group.


Growth and development occur in specific directions. Development is closely related to maturation of the nervous system, and occurs in the cephalocaudal direction (head to tail), which is logical; for example, motor control must be established in the brain before the neuromuscular connections required by leg and back muscles for walking develop. The second direction is from the centre of the body outwards (proximodistal); for example, infants learn to control shoulder movements before they control hand movements (Santrock 2007).


There is a sequence, order and pattern to growth and development. There are certain developmental tasks that must be accomplished during each stage. A developmental task is a set of skills and competencies specific to each developmental stage, which children must accomplish to deal effectively with their environment. Each stage lays the foundation for the next stage of development. The stages of development are:








Development encompasses various aspects — motor, vision and hearing, speech and language, intellectual, emotional, personality, moral and social. Although there is an orderly pattern to the processes, the rate of growth and development varies among individuals.



CONCEPTION


Conception, formally defined as the union of a single egg and sperm (gametes), is the benchmark of the beginning of a pregnancy. This event does not occur in isolation but as a result of a series of events, including ovulation (release of the egg), union of the gametes and implantation of the embryo into the uterus. Only after all these events are successfully completed can the process of embryonic and fetal development begin (Figure 15.1 and Table 15.4).



TABLE 15.4 Fetal growth terms


















Term Time period in fetal development
Ovum From ovulation to conception (fertilisation)
Zygote From conception (fertilisation) to implantation
Embryo From implantation to 8 weeks after conception
Fetus From 8 weeks after conception until term

(Sherblom Matteson 2001)


Fertilisation of the ovum occurs in the distal third of the uterine (fallopian) tube. The fertilised ovum (zygote) develops by simple cell division as it travels to the uterus. When it reaches the uterus, it is a sphere of cells and is referred to as a morula. The morula separates into an outer (ectodermal) and an inner (endodermal) cell mass, fluid forms and fills the space between the two layers, and the structure is then referred to as a blastocyst. The outer layer of the blastocyst becomes the trophoblast and will develop into the placenta and outer membrane, while the inner layer will develop into the embryo, cord and inner membrane. Between these two layers a third layer (mesoderm) will form.


Implantation (embedding in the endometrium) occurs about 10 days after fertilisation and normally occurs in the upper body of the uterus. After implantation, the lining of the uterus grows over the blastocyst and pregnancy is established. From this stage onwards the lining of the uterus is termed the decidua (Marieb 2004).


The inner cell mass of the blastocyst differentiates into three distinct layers:





As development continues, a cavity appears above the ectoderm. The lining of this amniotic cavity becomes the amniotic membrane, which secretes fluid that makes up part of the ‘liquor’ (the fluid that surrounds the embryo). The amniotic cavity enlarges so that eventually the embryo is suspended by the umbilical cord in a closed sac (membranes) of amniotic fluid.


The embryo continues to develop until by the end of the 2nd month it resembles a human, and is called a fetus. From this stage onwards the major activities are growth and organ specialisation. By the end of 40 weeks the fetus is about 50 cm long and weighs between 2.7 and 4.1 kg (Table 15.5).


TABLE 15.5 Embryonic and fetal growth and development




































Zygote (5 weeks) Complete sac 1 cm in diameter covered with chorionic villi. No recognisable human characteristics
Embryo (6 weeks) Sac 2–3 cm in diameter, weight 1 g. Head enlarges, arm and leg buds forming, primitive heart beginning to function, circulation in primitive form, connections made between vessels in chorion
10 weeks Embryo 4 cm long. External genitals appear, anal membrane breaks down, hands and feet recognisable, human form apparent
Fetus (12 weeks) Fetus 8 cm long, weight 15 g. Fingers and toes, eyes and ears, circulation and kidneys developed, nasal septum and palate have fused, endocrine glands and nervous system begin to function
16 weeks Fetus 16 cm long, weight 110 g. Sex easily identifiable, fingernails visible, good heartbeat, fetal movements felt. Basic development complete — the fetus now has to mature
20 weeks Length 22 cm, weight 300 g. Vernix on skin, lanugo (fine hair) on body, eyebrows, fetus now legally viable
24 weeks Length 30 cm, weight 600 g. Wrinkled skin, fat deposited, brain development continues
28 weeks Length 35 cm, weight 1000 g
32 weeks Length 42 cm, weight 1700 g. Skin red, wrinkled
36 weeks Length 46 cm, weight 2500 g. Nails reach fingertips
40 weeks Length 50 cm, weight 3400 g. Baby well covered with fat, skin red, not wrinkled, all organs functioning with the exception of the lungs

(modified from Bobak & Jensen 1993)

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Feb 12, 2017 | Posted by in NURSING | Comments Off on THEORIES OF GROWTH AND DEVELOPMENT: CONCEPTION THROUGH TO LATE CHILDHOOD
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