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Child Development
Robert S. Feldman
FIFTH EDITION
University of Massachusetts at Amherst
Chapter 5
Physical Development
in Infancy
Feldman / Child Development, 5th Edition
Copyright © 2010
Chapter 5 Key Questions
• How do the human body and nervous system
develop?
• Does the environment affect the pattern of
development?
• What developmental tasks must infants
accomplish in this period?
• How does nutrition affect physical
development?
• What sensory capabilities do infants
possess?
Feldman / Child Development, 5th Edition
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Physical Growth: The Rapid
Advances of Infancy
• Infants grow at a rapid pace over the first 2
years of their lives.
• By the age of 5 months, the average infant’s
birthweight has doubled to around 15 pounds.
By the first birthday, the baby’s weight has
tripled to about 22 pounds.
• The weight gains of infancy are matched by
increased length.
• By the end of the 1st year, the typical baby
grows almost a foot and is about 30 inches tall.
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Four Principles of Growth
• Cephalocaudal principle The principle that
growth follows a pattern that begins with the
head and upper body parts and then
proceeds down to the rest of the body
• The cephalocaudal growth principle means
that we develop visual abilities (located in the
head) well before we master the ability to
walk.
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Four Principles of Growth
• Three other principles help explain the patterns by which
growth occurs:
• Proximodistal principle The principle that development
proceeds from the center of the body outward
• Principle of hierarchical integration The principle that
simple skills typically develop separately and
independently but are later integrated into more complex
skills. For example, grasping a toy is not mastered until
move fingers.
• Principle of the independence of systems The principle
that different body systems grow at different rates For
example nervous system and sexual system mature
differently
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The Major Principles Governing Growth
page 115
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Nervous System = The system of cells, tissues,
and organs that regulates the body's responses to
internal and external stimuli. In vertebrates it
consists of the brain, spinal cord, nerves, ganglia,
and parts of the receptor and effector organs.
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Hemispheres of the Brain
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The Nervous System and Brain:
The Foundations of Development
• Neuron The basic nerve cell of the nervous
system (Review neuron network on page
117)
• Neurons can communicate with other cells,
using a cluster of fibers called dendrites at
one end.
• Dendrites receive messages from other cells.
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The Nervous System and Brain:
The Foundations of Development
• At their opposite end, neurons have a long
extension called an axon, the part of the
neuron that carries messages destined for
other neurons.
• Synapse The gap at the connection between
neurons, through which neurons chemically
(neurotransmitters) communicate (from axon
to terminal buttons) with one another.
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Synaptic Pruning = Neurological regulatory
processes, which facilitate a change in
neural structure by reducing the overall
number of neurons and synapses, leaving
more efficient synaptic configurations.
• Babies are actually born with many more
neurons than they need.
• In addition, although synapses are formed
throughout life, based on our changing
experiences, the billions of new synapses
infants form during the first 2 years are more
numerous than necessary.
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Synaptic Pruning
• After birth, neurons continue to increase in
size. In addition to growth in dendrites, the
axons of neurons become coated with myelin
• Myelin A fatty substance that helps insulate
neurons and speeds the transmission of
nerve impulses
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Synaptic Pruning
• The neurons also reposition themselves as
they grow, becoming arranged by function.
• Some move into the cerebral cortex, the
upper layer of the brain, while others move to
subcortical levels, which are below the
cerebral cortex.
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Synaptic Pruning
• The subcortical levels, which regulate such
fundamental activities as breathing and heart
rate, are the most fully developed at birth.
• http://faculty.washington.edu/chudler/lobe.ht
ml (Brain Lobes)
• http://faculty.washington.edu/chudler/split
.html (Hemispheres)
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Environmental Influences
on Brain Development
• Brain development, much of which unfolds
automatically because of genetically
predetermined patterns, is also strongly
susceptible to environmental influences.
• Plasticity The degree to which a developing
behavior or physical structure is modifiable
due to experience
• Brain Plasticity is greatest during first several
years of life
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Environmental Influences
on Brain Development
• Compared with those brought up in more enriched
environments, infants raised in severely restricted settings
are likely to show differences in the brain’s structure and
weight
• Sensitive period A specific time when organisms are
particularly susceptible to certain kinds of stimuli in their
environment (Refer to page 117)
• A sensitive period may be associated with a behavior—
such as the development of full vision—or with the
development of a structure of the body, such as the
configuration of the brain.
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Environmental Influences
on Brain Development
• Developmentalists suggest that there are
many simple ways parents and caregivers
can provide a stimulating environment that
will encourage healthy brain growth.
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Integrating the Bodily Systems:
The Life Cycles of Infancy
• In the first days of life, infants’ body rhythms
govern the infant’s behavior, often at
seemingly random times.
• Rhythms Repetitive, cyclical patterns of
behavior
• State The degree of awareness an infant
displays to both internal and external
stimulation (Page 119)
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Primary Behavioral States
(Page 119)
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Integrating the Bodily Systems:
The Life Cycles of Infancy
• Some of the different states that infants
experience produce changes in electrical
activity in the brain.
• These changes are reflected in different
patterns of electrical brain waves, which can
be measured by a device called an
electroencephalogram (EEG).
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Sleep: Perchance to Dream?
• At the beginning of infancy, the major state
that occupies a baby’s time is sleep.
• On average, newborn infants sleep some 16
to 17 hours a day. However, there are wide
variations.
• Rapid eye movement (REM) sleep The
period of sleep that is found in older children
and adults and is associated with dreaming
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REM = Dreaming
(Page 120)
-REM sleeps takes up one half of infant’s sleep compared
to 20% of adult sleep
-Infants do not have experiences to dream about.
-REM sleep for infants is a means of stimulation of the
brain, or autostimulation
-Refer to genetic, environment and cultural influences
on sleep on page 120)
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SIDS: The
Unanticipated Killer
• Sudden infant death syndrome (SIDS) The
unexplained death of a seemingly healthy
baby
• SIDS strikes about 1 in 1,000 infants in the
United States each year.
• Although it seems to occur when the normal
patterns of breathing during sleep are
interrupted, scientists have been unable to
discover why that might happen.
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SIDS: The
Unanticipated Killer
• Although no reliable means for preventing the
syndrome has been found, the American
Academy of Pediatrics now suggests that
babies sleep on their backs rather than on
their sides or stomachs—called the back-tosleep guideline.
• The number of deaths from SIDS has
decreased significantly since these guidelines
were developed.
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Motor Development
• The shape and proportions of newborn
babies are simply not conducive to easy
mobility.
• Their heads are so large and heavy that
young infants lack the strength to raise them.
• Because their limbs are short in relation to
the rest of the body, their movements are
further impeded.
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Motor Development
• Furthermore, their bodies are mainly fat, with
a limited amount of muscle; the result is that
they lack strength.
• Fortunately, it doesn’t take too long before
infants begin to develop a remarkable amount
of mobility.
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Reflexes: Our Inborn
Physical Skills
• Reflexes Unlearned, organized involuntary
responses that occur automatically in the
presence of certain stimuli
• Newborns enter the world with a repertoire of
reflexive behavioral patterns that help them
adapt to their new surroundings and serve to
protect them.
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Some Basic Reflexes in Infants
page 123
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Name the Reflex......
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Reflexes
f
g.
h.
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Ethnic and Cultural Differences
and Similarities in Reflexes
• Although reflexes are, by definition,
genetically determined and universal
throughout all infants, there are actually some
cultural variations in the ways they are
displayed.
• In some cases, reflexes can serve as helpful
diagnostic tools for pediatricians.
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Ethnic and Cultural Differences
and Similarities in Reflexes
• Because reflexes emerge and disappear on a
regular timetable, their absence—or
presence—at a given point of infancy can
provide a clue that something may be amiss
in an infant’s development.
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Gross Motor Skills
• The motor skills of newborn infants are
unsophisticated; still, young infants are able
to accomplish some kinds of movement.
• As their strength increases, they are able to
push hard enough against the surface on
which they are resting to propel their bodies
in different directions.
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Gross Motor Skills
• Crawling appears typically between 8 and 10
months.
• Walking comes later; half of all infants can
walk well by the end of 12 months.
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Fine Motor Skills
• By the age of 3 months, infants show some ability
to coordinate the movements of their limbs.
• The sophistication of fine motor skills continues to
grow. By the age of 11 months, infants are able to
pick up objects as small as marbles.
• Grasping, like other motor advances, follows a
sequential developmental pattern in which simple
skills are combined with more sophisticated ones.
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Dynamic Systems Theory: How
Motor Development Is Coordinated
• Each skill (such as a baby’s ability to pick up
a spoon and guide it to her lips) advances in
the context of other motor abilities (such as
the ability to reach out and lift the spoon in
the first place).
• Refer to chart on page 125
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Dynamic Systems Theory: How
Motor Development Is Coordinated
• Furthermore, as motor skills are developing,
so also are nonmotoric skills such as visual
capabilities.
• Dynamic systems theory A theory of how
motor skills develop and are coordinated
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Developmental Norms: Comparing
the Individual to the Group
• Norms The average performance of a large
sample of children of a given age
• Brazelton Neonatal Behavioral
Assessment Scale (NBAS) A measure
designed to determine infants’ neurological
and behavioral responses to their
environment
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Developmental Norms: Comparing
the Individual to the Group
• Although the norms provided by scales such
as the NBAS are useful in making broad
generalizations about the timing of various
behaviors and skills, they must be interpreted
with caution.
• Because norms are averages, they mask
substantial individual differences in the times
when children attain various achievements.
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Nutrition in Infancy: Fueling
Motor Development
• The rapid physical growth that occurs during
infancy is fueled by the nutrients that infants
receive.
• Without proper nutrition, infants cannot reach
their physical potential, and they may suffer
cognitive and social consequences as well.
• Infants should consume about 50 calories per
day for each pound they weigh—an allotment
that is twice the suggested caloric intake for
adults.
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Malnutrition
• Malnutrition, the condition of having an
improper amount and balance of nutrients,
produces several results, none good.
• Children who have been chronically
malnourished during infancy later score lower
on IQ tests and tend to do less well in school.
• Children in the United States rarely become
severely malnourished, but children living in
poverty remain susceptible to undernutrition,
in which there is some deficiency in diet.
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Malnutrition
• Malnutrition during the 1st year can produce
marasmus, a disease in which infants stop
growing.
• Older children are susceptible to kwashiorkor,
a disease in which a child’s stomach, limbs,
and face swell with water.
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Marasmus
= is a form of severe malnutrition
characterized by energy deficiency. A child with
marasmus looks emaciated. Body weight may be
reduced to less than 80% of the average weight that
corresponds to the height. Marasmus occurrence
increases prior to age 1, whereas kwashiorkor
occurrence increases after 18 months. It can be
distinguished from kwashiorkor in that kwashiorkor is
protein wasting with the presence of edema.
Marasmus
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Rickets
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Beriberi
Dry Beriberi
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Beriberi
Wet Beriberri
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Non Organic Failure to Thrive
• In some cases, infants who receive sufficient
nutrition behave as if they have been
deprived of food. The real cause, though, is
emotional. This is known as nonorganic
failure to thrive.
• Nonorganic failure to thrive A disorder in
which infants stop growing due to a lack of
stimulation and attention as the result of
inadequate parenting
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Obesity
• Obesity is defined as weight greater than
20% above the average for a given height.
• Although the evidence linking infant obesity to
adult obesity is inconclusive, what is apparent
is that the societal view that “a fat baby is a
healthy baby” is not necessarily correct.
• Given the lack of clarity regarding infant
obesity, parents should concentrate less on
their baby’s weight and more on providing
appropriate nutrition.
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Breast or Bottle?
• For the first 12 months of life, there is no
better food for an infant than breast milk.
• Breast milk not only contains all the nutrients
necessary for growth, but it also seems to
offer some degree of immunity to a variety of
childhood diseases.
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Breast or Bottle?
• Breast milk is more easily digested than
cow’s milk or formula, and it is sterile, warm,
and convenient for the mother to dispense.
There is even some evidence that breast milk
may enhance cognitive growth, leading to
high adult intelligence.
• Breast-feeding also offers significant
emotional advantages for both mother and
child, and may even be advantageous to
mothers’ health.
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Social Patterns in
Breast-feeding
• Although it has several advantages, only
about 70% of all new mothers in the United
States employ breast-feeding.
• Issues of age, social status, and race
influence the decision whether to breast-feed.
• The rates of breast-feeding are highest
among women who are older, have better
education, are of higher socioeconomic
status, and have social or cultural support.
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Introducing Solid Foods:
When and What?
• The American Academy of Pediatrics and the
American Academy of Family Physicians suggest
that babies can start solids at around 6 months,
although they aren’t needed until 9 to 12 months
of age.
• Solid foods should be introduced into an infant’s
diet gradually, one at a time, to allow awareness
of the child’s preferences and allergies.
• The timing of weaning, the gradual cessation of
breast or bottle-feeding, varies greatly.
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The Development
of the Senses
• The infant’s world grows increasingly
comprehensible as its ability to sense and
perceive the environment develops.
• Babies appear to thrive in an environment
enriched by pleasing sensations.
• Sensation The physical stimulation of the
sense organs
• Perception The sorting out, interpretation,
analysis, and integration of stimuli involving
the sense organs and brain
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Visual Perception:
Seeing the World
• The vision of newborns provides the same degree
of distance acuity as the uncorrected vision of many
adults who wear eyeglasses or contact lenses.
(p.138)
• Other visual abilities grow rapidly. For instance,
binocular vision, the ability to combine the images
coming to each eye to see depth and motion, is
achieved at around 14 weeks.
• Depth Perception – page132, tried Visual Cliff but
results were undetermined
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Visual Appeal
• Research has shown that infants reliably
prefer to look at stimuli that include patterns
than to look at simpler stimuli.
• Prefer curves, 3-D, human faces
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Auditory Perception:
The World of Sound
• Even in the womb, the fetus responds to
sounds outside of its mother.
• Furthermore, infants are born with
preferences for particular sound
combinations.
• Infants can discriminate groups of different
sounds, in terms of their patterns and other
acoustical characteristics quite well.
• Even more intriguingly, young infants are able
to discriminate one language from another.
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Smell and Taste
• The sense of smell is so well developed,
even among very young infants, that at least
some 12- to 18-day-old babies can
distinguish their mothers on the basis of smell
alone.
• Infants also develop taste preferences based
on what their mothers drank while they were
in the womb.
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Contemporary Views
on Infant Pain
• Infants are born with the capacity to experience
pain.
• Pain produces distress in infants. Their
heartbeat increases, they sweat, show facial
expressions of discomfort, and change the
intensity and tone of crying when they are hurt.
• Medical experts now endorse the use of
anesthesia and painkillers during surgery for
even the youngest infants.
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Responding to Touch
• Touch is one of the most highly developed sensory
systems in a newborn, and it is also one of the first
to develop; there is evidence that by 32 weeks after
conception, the entire body is sensitive to touch.
• Furthermore, several of the basic reflexes present
at birth, such as the rooting reflex, require touch
sensitivity to operate.
• Infants’ abilities in the realm of touch are
particularly helpful in their efforts to explore the
world.
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Multimodal Perception: Combining
Individual Sensory Inputs
• Multimodal approach to perception The
approach that considers how information that
is collected by various individual sensory
systems is integrated and coordinated
• Infants’ abilities at multimodal perception
showcase the sophisticated perceptual
abilities of infants, which continue to grow
throughout the period of infancy.
• Affordances The action possibilities that a
given situation or stimulus provides
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