Physical Development
in Infancy
Physical Growth and
Development In Infancy
Cephalocaudal & Proximodistal
Patterns
 Cephalocaudal sequence in which
greatest growth occurs at top (head),
working its way to neck, shoulders,
middle truck, so on…
 Proximodistal sequence in which
growth starts at center of body & moves
toward extremities
Development inside the womb and
out

Cepahalocaudal
development – head
to toe

Proximodistal
development –
inside out
Physical development

Principle of hierarchical
integration – simple
skills must be met
before more complex
skills can be achieved

i.e., learning how to
hold pencil precedes
writing

Principle of independent
systems – different
rates of growth within
the body

i.e., height and weight
can be independent of
each other
Height and Weight
Infants double their birthweight by four
months of age, tripled it by their first
birthday, & grow an inch a month during
their first year
 By 2 years of age, infants weigh
approximately 26 to 32 pounds & have
reached about one-half of their adult
height

The Brain

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Child is born with 100 billion nerve cells
Neuron - nerve cell that processes
information at cellular level.
Dendrites receive information from other
neurons, muscle or glands
Axon transmits information
Myelin sheath speeds information
transmission
Axon ends are the terminal buttons of the
neuron
The Brain’s Development
Between 10 and 26 weeks, the neuron
connections are generated at 250,000
per minute
 Following this cells move to appropriate
locations in brain in process called
migration
 Finally, they are ready for collecting &
processing information, known as cell
elaboration

Early Experience and the Brain

Scientific research on animals & humans who
have suffered brain damage, tells us that brain
produces trillions of cells in early development
which cannot possibly be used
 Animals reared in richly-stimulated
environments have more neuronal connections
than those reared in restricted environments
 Implication is children who are given a rich
environment very early on, will develop greater
neuronal connections for later use
There is some skepticism of this belief
Marion Diamond’s research

Maturation-genetic
map – cannot alter
this

However, this does
not mean that
environment cannot
affect anything
Marion
Diamond

Demonstrated that
an enriched
environment will
increase cell weight
and add to the
number of dendrites
on the neuron
An impoverished environment
decreases cell weight, may lead to a
loss of cells and the number of
dendrites will be reduced (synaptic
pruning)
Neural plasticity and critical periods

If the neural growth
is inhibited, then
development may
not be achieved

Does not affect the
person with
sensitive periods,
but critical periods it
does
Infant States
States of consciousness or levels of
awareness that characterize individuals.
Some states are:
 REM (rapid eye movement) sleep
 active sleep without REM
 indeterminate sleep
 drowsy
 inactive alert
 active awake
 crying

Nutrition

Growing research supports nutrition
programs for infants which will supply needed
nutrients for proper physical, cognitive &
emotional development
 Breast/Bottle Feeding - While most experts
believe that breast-feeding is nutritional better
for infant presents problems for working mom
 Malnutrition - Infants who are malnourished in
their first year may suffer from marasmus
wasting away of body tissues caused by
severe protein-calorie deficiency leads to
severe underdevelopment of child’s cognitive,
physical & emotional growth
Motor Development
Gross and Fine Motor Skills
Skills infant learns through muscle
control
 Gross skills utilize large muscles for
larger motor activities such as moving
arms or legs
 Fine skills involve more finely turned
movements such as finger dexterity.

Reflexes of children

Rooting reflex –
– You can often stroke
the baby’s cheek and
see this reflex
Eyeblink Reflex

Reflexive blinking that
protects baby from
bright lights and
foreign objects.
Sucking Reflex

Babies instinctively
begin to suck at
objects placed in the
mouth.
Moro Reflex

When the baby hears a loud noise or their head
falls back, they may instinctively extend arms
out, arch its back and bring arms toward each
other as though they are trying to grab
someone.
Palmar and Plantar Grasp Reflex

Palmar-Curling of the
fingers around an object
that touches the palms.

Plantar-Stroke bottom of
foot, curl toes
Tonic Neck Reflex

The tonic neck reflex, or fencer
response, is present at birth

This reflex usually disappears by 4-9
months.
Babinski Reflex

Babinski's reflex
occurs when the great
toe flexes toward the
top of the foot and the
other toes fan out
after the sole of the
foot has been firmly
stroked
 abnormal after the
age of 2.
Sensory Development

Discerning faces - 1 month old
babies appear to be able to
distinguish mother’s face from
stranger’s as long as they hear
the mother’s voice as well

At 3 months, baby appears to
distinguish mother from stranger
with face alone
Sight

Babies are born legally blind with a
vision of 20/600 – you need to be no
more than 8 inches from their face

By 6 months they are at 20/100 – you
need to be at least a few feet away

By 9 months they are at 20/60 – they
can see you across the room
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By age two, vision will be about 20/20
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For the first couple of months, babies
will be able to distinguish patterns, but
tend to respond to blacks and reds

By 5 or 6 months, babies begin to
discern colors
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A word about pastels
Hearing
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By 1 month, babies can distinguish
between the smallest variations in
sound
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By 6 months, they have developed the
ability to understand and make all of the
sounds necessary for their language
structure
Touch

Newborns have a well-developed sense
of touch and will, over time, come to use
this sense a lot

Babies will begin to explore their world
using tactile sensations, which is why
many of the toys for infants have
different textures
Smell

1-day-old infants can distinguish
between some smells

1 ½-month-old infants can distinguish
between the smell of their mother and
that of a stranger (which is why people
tell you to leave the baby with
something that has your smell on it)
Taste

Newborns appear to prefer the taste of
sweet and salty and dislike bitter-tasting
things

It has been observed that during
pregnancy infants will lick the placenta
wall which may help to develop a sense
of taste
Depth Perception

Visual cliff experiment
-
Visual Cliff Experiment

3-month-old babies would have their
heartbeat decrease when approaching
the “ledge”

6-month-old babies would have their
heartbeat increase when approaching
the “ledge” – would not crawl across,
although some did when mother
prompted them to
Depth Perception
 Three-dimensional
vision does not
develop until about 4 months
 Brain needs experience to develop
3-D vision
 Crawling builds 3-D vision.