In our previous blog we have learnt about 'Growth' and
'Development'. Before we concentrate on the factors affecting growth and
development. Let's take a quick look at the difference between growth and
development.
Growth is indicative i.e.
increase in body, size, weight etc. It is quantitative progress.
It is a physical change. It is external in nature. It stops at certain
stage and is a physical progress.
Development is not
indicative. It qualitative progress. It is psychological change.
It is internal in nature. It is continuous process and is a
cognitive progress.
Human growth and
development is affected by a large number of factors. These factors
include internal factors and external factors. Internal factors are conditions
within the body.
The integrated nature of growth,
maturation and development are largely maintained by a constant interaction of
genes, hormones, nutrients and other factors. These factors also influence
physical performance. Some are hereditary in origin. Others, such as season,
dietary restriction, severe psychological stress, originate in the environment
and simply affect the rate of growth at the time they are acting. Others again,
such as socio-economic class, reflect a complicated mixture of hereditary and
environmental influences and probably act throughout the whole period of
growth.
Human organism is the
product of heredity and environment. Potentialities of development, and not
acquired skills, knowledge and attitudes are handed down from parents to their
off-springs. Again, favourable environmental influences and specific training
are required to develop a superior personality or to improve a weak one.
To better understand the concept the
nature-nurture both influence the growth and development of an individual. The
final end product that we obtain is the product generated after the influence
of the internal and external factors. Let's learn in detail about these
factors.
Internal Factors Include:
1.Hereditary factors
2.Biological or Constitutional factors
3.Intelligence
4.Emotional factors
5.Social factors.
Internal factors are the factors which are within the
individual.
Hereditary factors: Hereditary
factors play their part at the time of conception in the mother’s womb. A
person’s height, weight and structure of the body, colour of hair and eye,
intelligence, aptitudes and instinct are all decided by these hereditary
influences. Hereditary factors play a very important role in the growth
and development. The foetus hereditary is influenced by the generational
characters transmitted by the parents to the child. The nerves system, physical
structures and physiological functions all are demonstrated by the hereditary
thus passed, if it is dominating in an individual, environmental influence is
minimum.
Biological and Constitutional factors: A child’s constitutional make-up, somatic structure,
physique and body chemistry influences his growth and development throughout
his life. The growth and development of an individual is influenced by
the body structure, physique and body chemistry of an individual. I the body
structure, physique i.e. the individual has any organ deformities or say
undeveloped or underdeveloped nervous system, the individual cannot function
normally. It effects the cognitive and physical functioning. The chemistry of
the body is also affected if the body of an individual has a malfunctioning in
the secretions of the endocrine glands.
Endocrine glands are commonly referred
to as ductless glands, or glands of internal secretion. They secrete chemical
substances, hormones directly into the bloodstream. Human growth is affected by
biochemical products such as hormones. Hormones are regarded as growth
promoting substance. Probably all the endocrine glands influence growth. Most
of the hormones are secreted by the endocrine glands and play a significant
role in regulating the pattern of growth and development as per instructions of
the genes.
The most important hormone
controlling growth from birth up to adolescence is growth hormone or
somatotrophin. This is in fact a polypeptide secreted by the pituitary. It
helps growth of bones and thereby increases the height of persons. Growth
hormone controls the rate at which growth takes place up to the time of steroid
- induced adolescent spurt.
Its administration causes the amino
acids to be incorporated into tissues to form new protein. It also causes an
overall growth rate of most of tissues including brain.
Thyroid hormone plays a vital
role throughout the whole of growth. The activity of the thyroid, judged by the
basal metabolic rate, decreases gradually from birth to adolescence. In
hypothyroidism growth is delayed, skeletal maturity; dental maturity and growth
of the brain are all affected. During adolescence a new phase of
growth occurs under the control of steroid hormones secreted by the adrenals
and gonads. The gonads of both sexes secrete estrogens in small quantities from
the time of birth onwards. At puberty the estrogens level rise, sharply in
girls and to a much more limited extent in boys; the sex differences is
possibly due to an inhibitory hormone secreted by the seminiferous tubules of
the testicle. Testosterone, produced by the testicle, is important in
stimulating growth and it is responsible for the greater growth of muscle.
Gonadotrophins are responsible for the growth of the ovaries and testis, and
later on the secretion of the amounts of estrogens and testosterone responsible
for the growth and development of secondary sex characters.
Intelligence: Intelligence contributes to the growth and development of
the individual. Intelligence is the
ability to learn about, learn from, understand, adjust, interact with the
environment and take right decision at right time. It affects the social
behaviour, moral judgment and emotional growth. Low grade intelligence is associated with retardation,
slow learning and poor performance. On the other hand, high grade intelligence
is associated with acceleration which includes social amicability, emotional
stability, moral judgement, fast decision making, adjustment with the
environment, quick learning and excellent performance.
Emotional factors:
Emotional factors include fear, anxiety, anger, jealousy etc. They have adverse
effect towards physical, social, mental, emotional and language development.
Emotional maturity plays a very important role in the growth and development of
the child.
Social factors: Social
factors affect a lot towards an individual's adaptability. It helps an
individual to adjust to the society and his environment.
The expression of feelings
about self, others, and things describe emotional development. Emotional and
social development are often described and grouped together because they are
closely interrelated growth patterns.
The sex of an individual also affects growth and
development. At birth, boys are slightly bigger in size than girls. When the
process of growth sets in after birth, girls exhibit rapid growth and attain
full size earlier than boys.
External factors: External factors influence growth
and development; they are outside or from external source as the
environment. Much of the physical growth depends partly
upon such environmental factors as sunlight, fresh air, conditions of climate
and partly' upon food and nutrition.
When we talk about the
environment, it can be the environmental influence on the foetus and environmental
influence after the birth of an individual.
Environmental influence
on the foetus happens when the foetus is still in the mother's womb. It
includes the effect of radiation, pollution, malnutrition, heavy work by the
mother and lack of proper care and affection from others.
Environmental influences
after birth include lack of proper care after the birth of a baby. After birth
proper care is required to avoid complications. Accidents and incidents make
the growth and development to lapse. If any damage occurs in brain, it renders
proper growth. Love, affection, good physical environment, proper nourishment,
medical care can bring harmony in growth and development.
There is a well-marked
seasonal effect on velocity of growth visible in most human growth data. Growth
in height is on average fastest in spring and growth in weight fastest in
autumn. This is true at all ages, including adolescence. The mechanism of the
seasonal effect is not known; probably variations in hormone secretion are
involved. Climate seems to have a very minor effect on overall rate of growth
in man. It has been suggested that each major race of mankind varies in stature
according to the climates in which they live. Seasonal variation in
growth has also been observed in many studies. Longitudinal studies have shown
that only about 30% of the children have cycles of increase and decrease in
growth velocity which are strictly seasonal. The remaining children show
accelerations and decelerations of growth which cannot be clearly related with
seasons.
Growth is closely related
with nutrition. A sufficiency of food is essential for normal growth. An
adequate supply of calories is naturally essential for the normal growth of
humans and the need varies with the phase of development. Nine different
amino acids have been claimed to be essential for growth and absence of any one
will result in disordered or stunted growth. Other factors are also essential
for growth. For example, zinc plays a part in protein synthesis and is a
constituent of certain enzymes; a deficiency of zinc causes stunting,
interference with sexual development and falling out of hair. Iodine is
needed for the manufacture of the thyroid hormones. Bone will not grow properly
without an adequate supply of calcium, phosphorus and other inorganic
constituents such as magnesium and manganese. Iron is required for the
production of haemoglobin. Vitamins play an important part in growth. Vitamin A
is thought to be control the activities of osteoblasts. In vitamin C deficiency
the intercellular substance of bone is inadequately formed. Vitamin D
deficiency is the cause of rickets. Malnutrition during childhood delays
growth, and malnutrition in the years proceeding adolescence delays the
appearance of the adolescent spurt. Growth studies have demonstrated that
malnutrition may cause serious impairment of growth. The term malnutrition
generally refers to the effects of an inadequate intake of calories or other
major dietary components such as proteins.
Malnutrition may also result from
diseases which decrease the appetite or interfere with digestion and
assimilation.
The physical growth of
human beings is definitely affected by cultural factors. Culture differs from
ethnic group to ethnic group. The body growth differences correlate with varied
cultural groups. The physical growth of the body follows some adaptations
in different geographical areas of distribution of the groups.
Socioeconomic influence on
human growth is also a well known factor. Children from different socioeconomic
levels differ in average body size at all ages that have been investigated. The
upper groups being always more advanced along the course to
maturity. The cause of this socio - economic differential are
probably multiple. Nutrition is almost certainly one, and with it all the
habits of regular meals, sleep, exercise and general organization that
distinguish, from the point of view, a good home from a bad one. Growth
differences are more closely related to the home conditions than to the
strictly economic status of the families and home conditions reflect the
intelligence and personality of the parents. Size of family exerts an indirect
influence on the rate of growth. In a large family with limited income the
children do not get proper nutrition. As a result the growth is affected. The
number of children in the family exerts an effect on the children’s rate of
growth. Children in large families have been shown to be usually smaller and
lighter than children in small families. Possibly this is because in large
families children tend to get less individual care and
attention.
