1) Infant development occurs in an orderly, predictable manner determined by intrinsic and extrinsic forces. Development proceeds from head to toe and proximal to distal. 2) Each developmental domain (physical, motor, cognitive, psychosocial) must be assessed within the context of ongoing developmental surveillance, as skills in one domain influence others. 3) Speech delays are common concerns but distinguishing isolated from true language delays is important for appropriate referrals. Understanding normal development helps recognize early pathologic patterns.

1. ARTICLE
Infant Growth and Development
Chris Plauche Johnson, MEd, MD* and Peter A. Blasco, MD†
For example, five-word sentences in
IMPORTANT POINTS a 2-year-old child who does not fol-
1. Infant development occurs in an orderly and predictable manner that
low simple commands may repre-
is determined intrinsically. It proceeds from cephalic to caudal and sent echolalia typical of autism.
proximal to distal as well as from generalized reactions to stimuli to The sentences are not meaningful
specific, goal-directed reactions that become increasingly precise. and have no communicative intent.
Extrinsic forces can modulate the velocity and quality of develop- Delays in one developmental
mental progress. domain may impair development
2. Each developmental domain must be assessed during ongoing in another domain. For example,
developmental surveillance within the context of health supervision. immobility due to neuromuscular
Generalizations about development cannot be based on the assessment disorders prevents exploration of the
of skills in a single developmental domain (ie, one cannot describe environment and, in turn, impedes
infant cognition based on gross motor milestones). However, skills in cognitive development arising
one developmental domain do influence the acquisition and assessment through manipulation of objects.
of skills in other domains.
Last, a deficit in one domain may
3. Speech delays are the most common developmental concern seen by
the general pediatrician, yet they often are not well understood or
compromise the assessment of skill
diagnosed expediently. A sound understanding of the distinction levels in another domain, even
between an isolated speech delay (usually environmental and often though development in the second
can be alleviated) and a true language delay (a combined expressive domain is normal. For example,
and receptive problem that implies more significant pathology) will it is difficult to assess problem-
help the clinician refer appropriately for precise diagnosis and solving skills in a child who has
appropriate management. cerebral palsy because the child
4. It is essential to understand normal development and acceptable may understand the concept of
variations in normal developmental patterns to recognize early matching geometric forms, yet be
patterns that are pathologic and that may indicate a possible unable to insert them physically
developmental disability. into a formboard.
5. Assessment of the quality of skills and monitoring the attainment Developmental milestones serve
of developmental milestones are essential to early diagnosis of as the basis of most standardized
developmental disabilities and expedient referral to early intervention
assessment and screening tools.
programs.
Although these screening tools pro-
vide the clinician with a structured
method of observing the infant’s
path unique. Intrinsic influences progress and help define a develop-
Introduction mental delay, many lack sensitivity.
“Infant” is derived from the Latin include the child’s physical charac-
teristics, state of wellness or illness, Parental concern in the face of
word, “infans,” meaning “unable to normal results in developmental
speak.” Thus, many define infancy temperament, and other genetically
determined attributes. Extrinsic screening should not be disregarded.
as the period from birth to approxi- Focusing narrowly on discrete
mately 2 years of age, when lan- influences during infancy originate
primarily from the family: the per- milestones may fail to reveal
guage begins to flourish. It is an atypical organizational processes
exciting period of “firsts”—first sonalities and style of caregiving by
parents and siblings, the family’s that are involved in the child’s
smile, first successful grasp, first developmental progress. Thus, it
evidence of separation anxiety, first economic status with its impact on
resources of time and money, and is important to analyze all mile-
word, first step, first sentence. The stones within the context of the
infant is a dynamic, ever-changing the cultural milieu into which the
infant is born. child’s history, growth, and physical
being who undergoes an orderly and examination as part of an ongoing
predictable sequence of neurodevel- Neurodevelopmental sequences
can be viewed broadly in terms of surveillance program. Only then is
opmental and physical growth. This
the traditional developmental mile- it possible to formulate an overall
sequence is influenced continuously
stones. Developmental milestones impression of the child’s true devel-
by intrinsic and extrinsic forces that
provide a systematic approach by opmental status and the need for
produce individual variation and
which to observe the progress of intervention.
make each infant’s developmental
the infant over time. Attainment Although milestones form the
of a particular skill builds on the foundation of the discussion, the
achievement of earlier skills; only primary intent of this article is to
* Associate Professor of Pediatrics, The
University of Texas Health Sciences Center,
rarely are skills skipped. When this provide broader insights into infant
San Antonio, TX. happens, the advanced skill may developmental processes and to help
† Associate Professor of Pediatrics, represent a “splinter” skill, that is, the clinician recognize warning
Johns Hopkins University, Baltimore, MD. a deviant developmental pattern. behaviors (“red flags”) indicative
224 Pediatrics in Review Vol. 18 No. 7 July 1997

2. CHILD DEVELOPMENT
Infancy
of developmental deficits. The mile- learning and shaped the child’s advances in behavioral genetics,
stone ages are not repeated in the development. This line of thinking together with recent discoveries
text to allow a more fluid discussion formed the philosophical basis for regarding innate infant abilities,
of developmental themes within the Head Start program of the have swung the pendulum back
each domain. Milestones have been 1960s. Freud (1920s) and Erikson in favor of nature as the primary
organized into domains to assist the (1950s) promoted developmental influence on the developmental
clinician in recognizing their inde- progress as a function of the resolu- process.
pendence as well as their interrela- tion of conflict. The quality of the
tionships. Tables illustrating all infant’s relationships with key indi-
domains at each age can be found in viduals was considered central to Developmental Snapshots:
Vaughan (see Suggested Reading). future development. The First Two Years of Life
Problem-solving and language mile- During the second half of the Before dissecting infant develop-
stones facilitate early identification century, the name of Piaget became ment into discrete steps within
of cognitive deficits. Adaptive skills almost synonymous with child each developmental domain, it is
(ie, skills related to independence development. Piaget was the first to valuable to view the infant at
in feeding, dressing, toileting) tradi- describe the infant as having intelli- discrete intervals. These 6-month
tionally have been included within gence. For centuries, it had been “snapshots” are displayed graphi-
the fine motor domain. However, assumed that the infant’s mind was cally in Figure 1. This gestalt
because these milestones are influ- a “blank tablet waiting to be written approach may help the clinician
enced by the social environment, on.” Because infants could not tell make sense of the interrelatedness
we have included them in a “psycho- us what they were experiencing, it of the precise changes within each
social domain.” Lists for emotional was believed that they saw and developmental domain.
and socialization milestones also are
included in this domain. In contrast
to motor and cognitive milestones, One principle of development in infancy is that it proceeds
psychosocial behaviors are influ- from head-to-toe — thus, arm movement comes before
enced more by extrinsic factors,
making them less well-defined.
leg movement.
heard little and thought even less, These four snapshots illustrate
Evolution of with consciousness as adults knew several generalizations about
Developmental Theory it not existing. Piaget revealed that neuro-developmental maturation
Developmental theory has been infants were, indeed, capable of over time:
shaped by the persistent debate of thinking, analyzing, and assimilat- 1. Responses to stimuli proceed
whether nature (intrinsic forces) or ing. He viewed development as from generalized reflexes involv-
nurture (extrinsic forces) is the pre- stage-like cognitive changes. The ing the entire body, as seen in the
dominant influence. At the turn of child actively explores objects in an newborn (and fetus), to discrete
the century, developmental theories effort to understand his or her envi- voluntary actions that are under
promoted nature as the major influ- ronment. Depending on the develop- cortical direction. This specializa-
ence. Gesell (early 1900s) was one mental stage, a child organizes this tion allows the child to move
of the first to study infant develop- information to form new theories from obligatory symmetric reac-
ment systematically and establish about the way the world works. tions when attending to a stimu-
developmental norms. Development It was not until the last part of lus (ie, vocalizations, arm wav-
was seen as a function of neurologic this century that emotional and ing, and kicking) to voluntary,
maturation and growth. Because social development began to receive asymmetric, and precise move-
advancing age and genetic endow- the same degree of attention as that ments toward a stimulus (ie,
ment were the chief mechanisms given to the motor and cognitive
grasping with one hand and
for change, babies were believed to domains. Research has revolved
inspecting with the other).
develop at a predetermined biologi- around theories regarding infant
cal pace, with parents needing to expression of emotion (Mandler, 2. Development proceeds from
do little more than provide a good 1970s), attachment (Bowlby, 1960s; cephalic to caudal and proximal
nurturing environment. Mahler, 1970s; and Ainsworth, to distal. Thus, arm movement
By mid-century, theories that 1980s), and temperament (Thomas comes under cortical direction
stressed the importance of nurture and Chess, 1970s). Once it was rec- and visual guidance before leg
began to prevail. Pavlov (1930s), ognized that newborns could demon- movement. With this, the child
Watson (1950s), and Skinner (1960s) strate distress (pain and hunger), progresses from hand-mouth to
promoted the opposing view that interest, and disgust, these facial foot-mouth play. The upper
development was a function of expressions have been used to study extremities become increasingly
learning. Operant conditioning information processing in infancy accurate in reaching, grasping,
(positive and negative reinforce- prior to the age when thoughts can transferring, and manipulating.
ments through social interactions or be verbalized. As the 20th century Distal development is seen when
environmental changes) promoted comes to a close, remarkable the infant can isolate and use the
Pediatrics in Review Vol. 18 No. 7 July 1997 225

3. CHILD DEVELOPMENT
Infancy
FIGURE 1. Developmental “snapshots” at 6, 12, 18, and 24 months.
index finger to poke and explore 3. Developmental progression is the house independently, opening
object parts. When this occurs in from dependence to indepen- doors, maneuvering stairs, and
concert with thumb opposition, dence. The totally dependent fetching desired objects. They
the fine pincer grasp is mastered. newborn progresses to a toddler can feed and undress themselves
Precise release of tiny objects who has mobility and manipula- and even may be toilet trained.
follows, so that fundamental tive skills that enable him or her This new autonomy becomes
manipulative skills reach adult to explore most of the environ- the foundation for the challeng-
levels by the end of infancy. ment. Toddlers can move about ing “twos.”
226 Pediatrics in Review Vol. 18 No. 7 July 1997

4. CHILD DEVELOPMENT
Infancy
TABLE 1. Average Physical Growth Parameters
OCCIPITOFRONTAL
AGE CIRCUMFERENCE HEIGHT WEIGHT DENTITION
Birth 35.0 cm 50.8 cm 3.0 to 3.5 kg Central incisors—6 mo
(13.8 in) (20.0 in) (6.6 to 7.7 lb) Lateral incisors—8 mo
+2 cm/mo (0 to 3 mo) +25.4 cm Regains birthweight by 2 wk
+1 cm/mo (3 to 6 mo) Doubles birthweight by 5 mo
+.5 cm/mo (6 to 12 mo)
Mean = 1 cm/mo
1 year 47.0 cm 76.2 cm 10.0 kg First molars—14 mo
(18.5 in) (30.0 in) (22 lb) Canines—19 mo
+2 cm +12.7 cm Triples birthweight
2 years 49.0 cm 88.9 cm 12.0 to 12.5 kg Second molars—24 mo
(19.3 in) (35.0 in) (26.4 to 27.5 lb)
Quadruples birthweight
Physical Growth cephaly can be seen with above- Dysmorphism
Growth milestones are the most average cognitive capability. Micro- Although most isolated minor dys-
predicable, although they must be cephaly associated with genetic or morphic features are inconsequen-
viewed within the context of each acquired disorders reflects cerebral tial, the presence of three or more
child’s specific genetic and ethnic pathology and almost always has may indicate the presence of devel-
influences. It is essential to plot the cognitive implications. opmental dysfunction. Almost 75%
child’s growth on gender- and age- Macrocephaly may be due to of these minor superficial dysmor-
appropriate charts. Charts now are hydrocephalus, which is associated phisms can be found by examining
available for some ethnic groups as with an increased incidence of cog- the face, skin, and hands. The
well as for a few genetic syndromes nitive deficits, especially learning presence of both minor and major
(eg, Down and Turner syndromes). disabilities. Macrocephaly without abnormalities may indicate a more
Fetal weight gain is greatest during hydrocephalus, far from being a serious genetic syndrome. In many
the third trimester. During the first predictor of advanced intelligence, instances, dysmorphic features will
few months of life, this rapid growth also is associated with a higher lead to the diagnosis of a clinical
continues, after which the growth prevalence of cognitive deficits. syndrome during the neonatal period
rate decelerates (Table 1). Birth- It may be due to metabolic or and predate the recognition of any
weight is regained by 2 weeks of age anatomic abnormalities. In about neurodevelopmental deficits.
and doubles by 5 months. Height 50% of cases, macrocephaly is
does not double until between 3 and familial, and the implications are
4 years of age. Head growth during benign in terms of intellect. When Motor Development
the first 5 or 6 months is due to evaluating infants whose macro- To make a meaningful statement
continued neuronal cell division. cephaly is isolated, the finding of about an infant’s motor competence,
Later, increasing head size is due a large head size in one or both the pediatrician should organize
to neuronal cell growth and support- parents can be reassuring. data gathered from the history,
ing tissue proliferation. physical examination, and neuro-
Height and Weight developmental examination accord-
Although the majority of individuals ing to the following schema:
RED FLAGS IN who are of below- or above-average
PHYSICAL GROWTH 1) motor developmental milestones,
size are otherwise normal, there is 2) the classic neurologic examina-
Occipitofrontal Circumference an increased prevalence of develop- tion, and 3) cerebral neuromotor
Large and small head size both are mental disabilities in these two maturational markers (primitive
relative red flags for developmental subpopulations. Many genetic syn- reflexes and postural reactions).
problems. Microcephaly is associ- dromes are associated with short Motor milestones are extracted
ated with an increased incidence of stature; large stature syndromes are from the developmental history as
mental retardation, but there is no less common. Again, when consider- well as from observations during
straightforward relationship between ing deviation from the norm in the the neurodevelopmental examina-
small head size and depressed intel- specific child, family characteristics tion. Reference tables of sequential
ligence. As a reflection of normal must be reviewed. The concept of gross and fine motor milestones
variation, microcephaly is not asso- mid-parental height is useful in are necessary (Table 2).
ciated with structural pathology of determining whether a given child’s Results of assessment in any
the nervous system or with low size is appropriate for his or her domain is summarized best as indi-
intelligence. Furthermore, micro- familial growth pattern. cating a developmental age for the
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5. CHILD DEVELOPMENT
Infancy
TABLE 2. Motor Development
MOS. GROSS MOTOR SKILLS FINE MOTOR SKILLS RED FLAGS
1 Head up in prone Hands tightly fisted
2 Chest up in prone position Retains rattle (briefly) if placed in hand Rolling prior to
Head bobs erect if held Hands unfisted half of time 3 months may
sitting indicate hypertonia
3 Partial head lag Hands unfisted most of time
Rests on forearms in Bats at objects
prone Sustained voluntary grasp possible if
object placed in ulnar side of hand
4 Up on hands in prone Obtains/retains rattle
Rolls front to back Reaches/engages hands in supine
No head lag Clutches at objects
5 Rolls back to front Transfers objects hand-mouth-hand Poor head control
Lifts head when pulled Palmar grasp of dowel, thumb
to sit adducted
Sits with pelvic support
Anterior protection
6 Sits-props on hands Transfers objects hand-hand
Immature rake of pellet
7 Sits without support Radial-palmar grasp of cube W-sitting and bunny
Supports weight and Pulls round peg out hopping, may
bounces while standing indicate adductor
Commando crawls spasticity or
Feet to mouth hypotonia
Lateral protection Inferior scissors grasp of pellet; rakes
object into palm
8 Gets into sitting position Scissors grasp of pellet held between
Reaches with one hand thumb and side of curled index finger
while 4-point kneeling Takes second block; holds 1 block in each
hand
9 Pulls to stand Radial-digital grasp of cube held with Persistence of
Creeps on hands and thumb and finger tips primitive reflexes
knees may indicate
neuromotor
disorder
Inferior pincer grasp of pellet held
between ventral surfaces of thumb
and index finger
continued
228 Pediatrics in Review Vol. 18 No. 7 July 1997

6. CHILD DEVELOPMENT
Infancy
TABLE 2. Motor Development (continued)
MOS. GROSS MOTOR SKILLS FINE MOTOR SKILLS RED FLAGS
10 Cruises around furniture Isolates index finger and pokes
Walks with 2 hands held Clumsy release of cube into box;
hand rests on edge
Pincer grasp, held between distal pads
of thumb and index finger
11 Stands alone
Walks with 1 hand held
12 Independent steps Fine pincer grasp of pellet between Failure to develop
Posterior protection finger tips protective reactions
Marks with crayon may indicate
Attempts tower of 2 cubes neuromotor
Precise release of cube disorder
Attempts release of pellet into bottle
14 Walks well Tower of 2 cubes
independently Attains third cube
16 Creeps up stairs Precise release of pellet into small
Runs stiff-legged container
Climbs on furniture Tower of 3 cubes
Walks backwards
Stoops and recovers
Imitates scribble
18 Push/pulls large object Tower of 4 cubes Hand dominance
Throws ball while Crudely imitates single stroke prior to 18 months
standing Scribbles spontaneously may indicate
Seats self in small chair contralateral
weakness
20 Walks up stairs with Completes square pegboard
hand held
22 Walks up stairs with rail, Tower of 6 cubes
marking time
Squats in play
24 Jumps in place Train of cubes without stack Inability to walk up
Kicks ball Imitates vertical stroke and down stairs
Walks down stairs with may be the result
rail, marking time of lack of
Throws overhand opportunity
Illustrations and accompanying text modified with permission from the Erhardt Developmental Prehension Assessment. In Erhardt RP.
Developmental Hand Dysfunction: Theory Assessment, Treatment. 2nd ed. San Antonio, Tex: Therapy Skill Builders; 1994.
Pediatrics in Review Vol. 18 No. 7 July 1997 229

7. CHILD DEVELOPMENT
Infancy
child. This approach makes it pos- with rolling), to sitting, and then prompted motor activities (eg,
sible to consider the child in terms through a standing/ambulating weight-bearing in sitting or stand-
of his or her level of functioning sequence (Fig. 2). Motor milestones ing) require adequate strength.
compared against chronologic age. do not take into account the quality Thus, weakness may be appreciated
For example, the developmental of a child’s movement. These best from observing the quality of
quotient (DQ) is the developmental sequences must be considered in the stationary posture and transition
age divided by chronologic age context of the motor portion of the movements. The Gower sign (arising
times 100 (see Example below). neurologic examination, including from sitting on the floor to standing,
This provides a simple expression observations of station and gait, using the hands to “walk up” one’s
of deviation from the norm. A where qualitative features can be legs) is a classic example and
quotient above 85 in any domain assessed. However, the neurologic indicative of pelvic girdle and
is considered within normal limits; evaluation of tone, strength, deep quadriceps muscular weakness.
a quotient below 70 is considered tendon reflexes, and coordination Not until 2 to 3 years of age does
abnormal. A quotient between 70 is difficult in very young infants the neurologic examination become
and 85 represents a gray area that because of the subjective nature easier and more meaningful as
warrants close follow-up. Values in of the assessments and the infant’s cooperation improves.
the upper limit of normal do not limited ability to cooperate. Clinical Station refers to the posture
particularly indicate supernormal experience is essential for obtaining assumed in sitting or standing and
abilities. Whether truly gifted ath- accurate and useful information. should be viewed from anterior,
letes can be recognized early by use Eliciting reflexes requires lateral, and posterior perspectives,
of this method is thought-provoking patience and repeated, yet gentle, looking for body alignment. Gait
but speculative. trial and error. Muscle tone (passive refers to walking and is examined
resistance) and strength (active resis- in progress. Initially, the toddler
GROSS MOTOR DEVELOPMENT tance) are a challenge to distinguish walks on a wide base, slightly
Gross motor development proceeds in the contrary infant. The best clues crouched, with the arms abducted
from a sequence of prone milestones can be obtained from observation, and slightly elevated. Forward
(beginning with head up and ending not handling. Spontaneous or progression is more staccato than
smooth. Movements gradually
become more fluid, the base narrows,
Example: Motor Quotient and arm swing evolves, leading to
an adult pattern of walking by
A 12-month-old boy is seen for health supervision. He is not walking 3 years of age.
alone, but he pulls up to stand (9 months), cruises around furniture The motor neuromaturational
(10 months), and walks fairly well when his mother holds both hands markers are the primitive reflexes,
(10 months). This child has a gross motor age of 10 months at a which develop during gestation
chronologic age of 12 months. Should this 2-month discrepancy be a and generally disappear between
concern? To decide, one should calculate the DQ by using these gross the third and sixth month after
motor milestones: birth, and the postural reactions,
motor age 10 months which are not present at birth but
DQ = × 100 = = 83 develop sequentially between 3 and
chronologic age 12 months
10 months of age (Fig. 3). The
The motor age and the developmental quotient are good summary Moro, tonic labyrinthine, asymmet-
descriptors of the child and have more meaning than plotting each ric tonic neck, and positive support
milestone. Because the lower limit is 70, this boy’s DQ falls within reflexes are the most useful clini-
the “suspect” or gray zone. In reality, infants falling into the gray zone cally (Fig. 4). As with all true
of motor domains usually do quite well and rarely require referral to an reflexes, each requires a specific
early intervention program. This is in contrast to those falling in the sensory stimulus to generate the
gray zones of the cognitive domains. stereotyped motor response. Normal
infants demonstrate these postures
0 Months 1 2 3 4 5 6
FIGURE 2. Chronologic progression of gross motor development. Adapted with permission from Piper MC, Darrah J. Motor
Assessment of the Developing Infant. Philadelphia, Penn: WB Saunders Co; 1994. Illustrations by Marcia Smith.
230 Pediatrics in Review Vol. 18 No. 7 July 1997

8. CHILD DEVELOPMENT
Infancy
inconsistently and transiently; those ing becomes more accurate, and bunny hopping, and persistent toe
who have central neurologic (ie, objects are brought to the mouth for walking may indicate spasticity.
cerebral) injuries show stronger oral exploration. As development Hand dominance prior to 18 months
and more sustained primitive reflex progresses from proximal to distal, of age should prompt the clinician
posturing. Primitive reflexes are reaching and manipulative skills are to examine the contralateral upper
somewhat difficult to gauge, even enhanced further, and precise manual extremity for weakness associated
in expert hands. The appearance exploration replaces oral exploration. with a hemiparesis.
of postural reactions in sequence During the second year, fine motor Analysis of the information
beginning after 2 or 3 months of age skills are assessed by observing the gathered in these areas makes it
is easier to elicit clinically and can manner in which the hands use relatively easy for the practitioner
provide great insight into the neuro- objects as tools (eg, blocks to build to reassure him- or herself (and the
motor integrity of young infants.
and crayons to draw). The close parents) about a child’s motor com-
Postural reactions are sought in
each of the three major categories: association between gross and fine petence or to identify motor impair-
righting, protection, and equilibrium. motor skills in the first year of life ment at an early age. Once a motor
These movements are much less evolves into a similar relationship abnormality has been identified,
stereotyped than the primitive between problem-solving and fine further assessment of its exact
reflexes, and they require a complex motor skills during the second year. nature and etiology is essential. This
interplay of cerebral and cerebellar One skill enables or promotes the almost always warrants referral to
cortical adjustments to a barrage development of the other. If progress an appropriate subspecialist or sub-
of sensory inputs (proprioceptive, in manual dexterity is slow, this may specialty team. Based on clinical
visual, vestibular) (Figs. 5 and 6). impede cognitive development via examination and history, the astute
They are easy to elicit in the manipulation of objects. clinician usually can decide into
normal infant but are markedly which category the motor disorder
slow in appearance in the infant RED FLAGS IN MOTOR falls: 1) static central nervous system
who has central nervous system DEVELOPMENT disorders, 2) progressive diseases,
damage. It is important to begin the motor 3) spinal cord and peripheral nerve
evaluation by observing the infant. injuries, or 4) structural defects.
FINE MOTOR DEVELOPMENT Pay particular attention to the hands;
In the first year of life, fine motor persistent fisting at 3 months of age
development is highlighted by the often is the earliest indication of Cognitive Development
evolution of a pincer grasp. During neuromotor dysfunction. Sponta- Cognitive processing skills are the
the second year of life, the infant neous postures (eg, froglegs and substrate for intelligence and include
learns to use objects as tools during scissoring) provide visual clues to a wide range of abilities (Table 3).
functional play. There are many hypotonia/weakness and spastic Intellectual development depends
stages in accomplishing these two hypertonus, respectively. Delays in on learning that contains three
skills; selected ones are illustrated the appearance of postural reactions components: attention, information
in Table 2. In the early months, the herald future delays in voluntary processing, and memory (which
upper extremities assist with balance motor development. An infant will includes both encoding and retrieval
and mobility. As balance in the sit- be unable to sit or walk indepen- of information). Intellectual develop-
ting position improves and the infant dently without intact protective and ment is reflected in advancing abili-
assumes biped mobility, the hands equilibrium mechanisms. Abnormal ties to comprehend, reason, and
become more available for manipula- movement patterns may indicate make judgments. Standardized intel-
tion of objects—their ultimate func- pathology. For example, early ligence tests generally measure two
tion. Primitive reflexes are inte- rolling (1 to 2 months), pulling forms of intelligence in the school-
grated, and the upper extremities directly to a stand at 4 months age child: verbal and performance
come under cortical control. Reach- (instead of to a sit), W-sitting, (or nonverbal). Such standardized
6 7 8 9 10 11 12
FIGURE 2. Continued
Pediatrics in Review Vol. 18 No. 7 July 1997 231

9. CHILD DEVELOPMENT
Infancy
tests are not available to measure
infant intelligence. How then, does
one recognize the attributes of ver-
bal and nonverbal intelligence in
infants? In the past two decades,
the discovery of visual habituation
techniques to assess infants’ atten-
tion was considered a breakthrough
in the study of infant cognition.
It is exemplified by one study that
describes 4-day-old infants listening
to a long series of “bee-see-lee”
sounds. When a novel “da” sound
was heard, the infants responded
with a change in heart rate and
faster, stronger sucking on a pacifier,
thereby indicating that very young
infants can perceive differences in
vowel sounds.
More complex studies using
simultaneous auditory and visual
stimuli indicate that infants also are
FIGURE 3. The declining intensity of primitive reflexes and the increasing role of
postural reactions represent at least permissive, and possibly necessary, conditions capable of organizing perceptions
for the development of definitive motor actions. From Capute AJ, Accardo PJ, across sensory modalities (cross-
Vining EPG, Rubenstein JE, Harryman S. Primitive Reflex Profile. Baltimore, Md: modal matching) without the lan-
University Park Press; 1978. Reprinted with permission. guage skills to describe them. For
example, 11-month-old infants
were presented a sequence of con-
tinuous and interrupted pure tones.
Two pictures were in the infants’
view throughout the experiment:
one contained a continuous line,
the other a dashed line. The infants
consistently matched the correct
visual stimulus to the auditory one,
inferring cross-modal matching and
some rudimentary understanding
of the concept of interruptedness.
Using these techniques, it has been
demonstrated that infants younger
than 1 year old can form a wide
range of fairly complex categorical
representations, including those for
faces, color, geometric shapes, and
orientation of lines.
The attempts to measure infant
responses precisely, such as those
FIGURE 4. Clinically useful reflexes. A. Tonic labyrinthine reflex. In the supine posi-
described previously, depend on
tion, the baby’s head is extended gently to about 45 degrees below horizontal. This sophisticated technology, including
produces relative shoulder retraction and leg extension, resulting in the “surrender infra-red photography for tracking
posture.” With head flexion to about +45 degrees, the arms come forward (shoulder infant eye gaze and pupillary dilata-
protraction) and the legs flex. B. Asymmetric tonic neck reflex (ATNR). The sensory tion, videotaping of facial reactions,
limb of the ATNR involves proprioceptors in the cervical vertebrae. With active or and electrophysiologic monitoring
passive head rotation, the baby extends the arm and leg on the face side and flexes of heart rate and evoked potentials.
the extremities on the occiput side (the “fencer posture”). There also is some mild The primary pediatrician can best
paraspinous muscle contraction on the occiput side that produces subtle trunk estimate infant intelligence by evalu-
curvature. C. Positive support reflex. With support around the trunk, the infant is ating problem-solving and language
suspended and then lowered to pat the feet gently on a flat surface. This stimulus
produces reflex extension at the hips, knees, and ankles so the infant stands up,
milestones. Language is the single
completely or partially bearing weight. Children may go up on their toes initially best indicator of intellectual poten-
but should come down onto flat feet within 20 to 30 seconds before sagging back tial; problem-solving skills are the
down toward a sitting position. From Blasco PA. Pediatric Rounds. 1992;1(2):1– 6. next best measure. Gross motor
Reprinted with permission. skills correlate least with cognitive
232 Pediatrics in Review Vol. 18 No. 7 July 1997

10. CHILD DEVELOPMENT
Infancy
The interdependence of language
and problem-solving development
becomes stronger as the child begins
to label objects and actions. Midway
through the second year, this ability
to label and categorize allows the
child to match objects that are the
same (car to a car and spoon to a
spoon) and later to match an object
to its picture. Nonverbal intelligence
is assessed by observing the infant
interact with test objects. In the
older child, it is assessed through
standardized pencil and paper tasks
FIGURE 6. The infant is seated comfort- or computerized tests.
FIGURE 5. Normal parachute reaction. ably, supported about the waist if neces- One aspect of nonverbal cogni-
The examiner has suspended the child sary. The examiner gently tilts the child
horizontally by the waist and lowered tive development deserves extra
to one side, noting righting of the head
him face down toward a flat surface. The back toward the midline, protective attention: object permanence, a con-
arms extend in front, slightly abducted extension of the arm toward the side, and cept studied extensively by Piaget.
at the shoulders, and the fingers spread equilibrium countermovements of the arm Prior to the infant’s mastery of
as if to break a fall. From Blasco PA. and leg on the opposite side. From object permanence, a person or
Pediatric Rounds. 1992;1(2):1–6. Blasco PA. Pediatric Rounds. 1992;1(2): object that moves “out of sight” is
Reprinted with permission. 1–6. Reprinted with permission. “out of mind”; its disappearance
does not evoke a reaction. The abil-
ity to maintain an image of a person
potential; most infants who are diag- “manipulating to learn.” Improved develops before that of an object.
nosed later with mental retardation macular vision (via myelination of The child will show interest in peek-
walk on time. the fovea) and refinement of the a-boo play, and separation anxiety
pincer grasp promote inspection will occur when a loved one leaves
PROBLEM-SOLVING of progressively smaller objects. the room. Shortly thereafter, the
As cognitive abilities continue to child will begin to look for an object
Problem-solving skills consist of
manipulating objects to solve a advance, the infant learns to shift that has been dropped. At first, an
problem (eg, choosing the correct attention between two objects (one auditory cue when it hits the floor
opening for a circular shape in a in each hand), compare, make is necessary to locate it. Later, the
three-piece form board). The infant’s choices, and discard or combine child will experience success in
ability to solve a problem depends objects. This sensory-motor phase finding an object that was dropped
on intact vision, fine motor coordi- of learning is the foundation for from sight and landed silently. Next,
nation, and cognitive processing. ongoing nonverbal intellectual the child will progress to finding an
During the early weeks of life, the development. object that has been hidden under a
infant explores the environment The 1-year-old child recognizes cloth or cup. A more complex task
visually. Later, these visual experi- objects and associates them with is locating an object that has been
ences reinforce movement. As the their functions. Thus, he or she wrapped inside a cloth. Success
upper extremities come under visual begins to use them functionally as requires persistence and memory of
guidance, reaching and grasping are “tools” instead of mouthing, bang- the object long enough to complete
enhanced. At first, the infant brings ing, and throwing them. This child the three-part unwrapping process.
objects to the mouth for oral explo- has left the period of sensory-motor The next skill in this sequence is
ration. Later, the infant visually play and entered the stage of func- the ability to locate an object under
examines an object held in one hand tional play. Play serves as a window double layers (eg, a cube is placed
while manipulating it with the other. into the infant’s thoughts and under a cup and then the cup is cov-
Isolation of the index finger pro- becomes particularly important dur- ered with a cloth). This is followed
motes more refined manipulation of ing the next stage of symbolic play. by the ability to locate an object
the various parts of objects, and the At this point, the infant uses toys after serial displacements. In this
infant becomes successful in discov- that represent real objects in actions task, an object is hidden under one
ering how they work (eg, fingering toward him- or herself (putting a toy cover and then changed to another
the clapper of the bell). Mouthing of telephone to the ear and vocalizing) one. The younger infant always
objects becomes less appealing. This and later in actions toward dolls or will look for it under the first cover,
precise manual-visual manipulation, teddy bears (putting a toy tea cup to even though the position change was
triggered by a heightened curiosity the doll’s mouth). The use of sym- seen. Later, he or she will become
and facilitated by a longer attention bols lays the foundation for imagi- successful with this task, as long as
span, heralds true “inspection” of nary play. This next stage of play each successive displacement still is
objects. The infant is progressing usually does not appear until 24 to witnessed. Not until the end of the
from “learning to manipulate” to 30 months of age. second year is the child able to
Pediatrics in Review Vol. 18 No. 7 July 1997 233

11. 234
TABLE 3. Cognitive Development
LANGUAGE
AGE IN
MONTHS PROBLEM-SOLVING RECEPTIVE EXPRESSIVE RED FLAGS
1 Fixes on red ring Alerts to sound Throaty noises Failure to alert to environmental stimuli
Follows face Cries may indicate sensory impairment
Infancy
2 Tracks horizontally past midline Regards speaker Social smile
Tracks vertically Coos
Vocalizes single vowel sounds
CHILD DEVELOPMENT
3 Regards a 1-inch block Chuckles
Follows ring circularly Echoes speaker immediately
Visual threat Cry varies (hunger, pain)
4 Reaches for objects Orients to voice Laughs out loud
Mouths objects “Ah-goo”
Shakes rattle Silent and listens to speaker; vocalizes
Regards objects while handling when speaker stops
5 Attains dangling ring Orients Bell—I Razzes (raspberries) Failure to reach for objects may indicate
Regards pellet Smiles and vocalizes to mirror motor, visual, and/or cognitive deficit
Sing-song vocalizations that mimic
speaker’s voice
6 Looks to floor when drops toy Babbles: “baba,” “gagaga” Absent babbling may indicate hearing
Attains partially hidden object Consonant production without symbolic deficit
Removes cloth covering face meaning or communicative intent
Discriminates strangers
7 Bangs/shakes toys Orients Bell—II Adult reinforcement begins to give Absent stranger anxiety may be due to
Attempts to grasp second cube; meaning to random babbling multiple care providers (eg, neonatal
drops first intensive care unit)
Pats mirror image
8 Pulls string to obtain ring Enjoys peek-a-boo and “Dada” inappropriately
Inspects ring/bell other gesture games Mimics sounds already in repertoire
Pediatrics in Review
Seeks yarn ball after fall; silent
landing
9 Rings bell Associates words with “Mama” inappropriately
Vol. 18
Bangs objects on table meanings Waves “bye bye”
Uncovers hidden object under cloth
10 Bangs two cubes together Comprehends “no” Dada/Mama appropriately Inability to localize sound may indicate
Isolates index finger and explores Orients to name unilateral hearing loss
by poking Orients Bell—III
Looks at pictures in book
No. 7 July 1997

12. 11 Uncovers toy under cup Looks for familiar family First word
member when named Imitates simple sounds
12 Looks selectively at round hole Follows command with Immature jargoning Persistent mouthing may indicate lack
on form board gesture (“Give me.”) Protoimpertive pointing of intellectual curiosity
Removes lid to find toy (goal = desired object)
Pediatrics in Review
13 Solves glass frustration task Looks appropriately 2 to 3 words Normal receptive language up to this
Unwraps toy in cloth when asked “Where “Oh-oh” point is compatible with hearing loss
Functional play is (familiar object)?”
Vol. 18
14 Combines two cubes into one Follows command without Names one object
hand to take third gesture Says “no” meaningfully
Dumps pellet after demonstration Protodeclarative pointing
(goal = adult’s attention)
No. 7 July 1997
15 Places circle in form board Points to a body part or 3 to 5 words Lack of consonant production may
Symbolic play toward self favorite toy Mature jargoning indicate mild hearing loss
16 Pellet in and out without Fetches object from another 5 to 10 words Lack of imitation may indicate deficits
demonstration room on request in hearing, cognition, and/or
Finds toy hidden under layered covers Points to 1 to 2 body parts socialization
Follows observed sequential
displacements
18 Matches pairs of objects Points to 3 body parts 10 to 25 words Lack of protodeclarative may indicate
Round form in reversed board Points to self Giant-words (“Thank you,” “Stop it,” problem in social relatedness
after searching “Let’s go”)
Symbolic play directed at doll Names one picture on command
20 Places square in form board Points to several clothing 2 word combinations (noun-noun)
Deduces location of hidden object items on request Holophrases
(unwitnessed displacement) Selects 2 of 3 familiar
objects
Points to 6 body parts
22 Completes 3-piece form board Points to 3 to 4 pictures 25 to 50 words Advanced, noncommunicative speech
Rapid vocabulary expansion (echolalia, rote phrases) may indicate
autism
24 Adapts to form board reversal Two-step commands 50+ words Absent symbolic play may indicate
Infancy
after 4 trials (“Close the book and 2 to 3 word sentences (noun-verb) problems in cognitive and/or social
Sorts objects give the doll to mommy”) Refers to self by name development
Matches objects to pictures Comprehends “another” Intelligibility = 50% +
Attempts to fold paper Points to 6 pictures Uses “I,” “you,” “me”
CHILD DEVELOPMENT
Understands me/you
235

13. CHILD DEVELOPMENT
Infancy
deduce the location of an object ing”). Between 10 and 18 months 1. Prespeech Period (0 to 10 months):
that is hidden without observing of age, word counts help in assess- Receptive language is character-
the displacement. ing a child’s expressive skills; after ized by an increasing ability to
Another important concept domi- 18 months of age, vocabularies localize sounds. Sound localization
nating this period of development is increase exponentially, and it is is assessed by using a noisemaker
causality. Initially, the infant acci- difficult to keep up with counts. such as a bell (Fig. 7). Expressive
dentally discovers that his or her Language includes receptive language consists of musical-like
actions produce a certain effect and expressive skills. Receptive vowel sounds (cooing) that
(eg, kicking the side of the crib skills reflect the ability to under- are interrupted by crying when
activates a mobile overhead). The stand language; expressive skills the baby has a need. At about
infant learns to repeat these actions reflect the ability to make thoughts, 3 months, the infant will begin
to obtain the same effects. Later, he ideas, and desires known to others. vocalizing immediately upon
or she will vary actions to cause Expression of language can take hearing an adult speak. One or
a novel effect (pulling a string to several forms: speech, gestures, two months later the infant is
obtain the ring). The concept of sign language, writing, typing, and silent and assumes a posture that
causality parallels social develop- “body language.” Thus, language implies he or she truly is “listen-
ment in which the infant learns to and speech are not synonymous. ing” to the speaker. These infants
manipulate the environment by cry- Speech is simply the vocal expres- make no vocalizations until the
ing or smiling to obtain the desired sion of language. A child can have speaker is quiet, mimic the
reaction from caregivers. As the normal language and yet be unable speaker, and then quiet again
infant approaches 2 years of age, to speak. Examples include children when the adult speaks. They
he or she will learn that apparent who are deaf and children who have appear to enjoy the “vocal tennis”
unrelated actions can be combined severe cerebral palsy. The child and repeat this for several cycles.
to produce an effect (eg, winding who has a hearing impairment At approximately 6 months of
a key to make a toy move). may use manual sign language age, the infant adds consonants to
to communicate. A child who has the vowel sounds in a repetitive
LANGUAGE DEVELOPMENT normal intelligence but cannot fashion (babbling). Soon the
Delays in language development are speak because of oral-motor dys- infant appears to initiate conver-
more common than delays in other sations. When a random vocaliza-
function related to cerebral palsy
developmental domains. Parents and tion (eg, “dada”) is interpreted by
may use a computer that is activated
pediatricians generally are less the parents as a real word, they
with a head stick. Conversely, a
show pleasure and joy. In so
familiar with language milestones. few children talk but fail to use
doing, adults give meaning to
Language is the most difficult speech to communicate (eg, children these first “words” and reinforce
domain to assess by observation who have autism). Their vocaliza- their repeated use.
because infants rarely vocalize tions consist of “parrot talk” or
spontaneously in the clinician’s echolalia that has no communicative 2. Naming Period (10 to 18 months):
office. For this reason, it is essential intent and, thus, does not represent This period is characterized by
for the clinician to obtain a thorough language. the infant’s realization that people
and accurate language history. The Language development during have names and objects have
pediatrician should become familiar infancy can be divided into three labels. It is an important turning
with milestone terminology and periods: prespeech, naming, and point in language development.
learn to give examples (eg, “razz- word combination periods. The “dada” and “mama” that
FIGURE 7. Orienting to sound of bell. In the first stage (5 months), when a bell is rung at one side of the infant’s head (A), the
infant turns horizontally to the correct side (B). In the second stage (7 months), when a bell is rung at one side of the head (A),
the infant localizes the sound by a compound visual maneuver consisting of a horizontal followed by a vertical component (C).
In the third stage (91⁄2 months), when a bell is rung to one side of the head (A), the infant localizes the sound by a single visual
movement (D). From Capute AJ, Accardo PJ. Clin Pediatr. 1978;17:850. Reprinted with permission.
236 Pediatrics in Review Vol. 18 No. 7 July 1997

14. CHILD DEVELOPMENT
Infancy
were vocalized randomly have nately points at the adult and the belong to mommy.” Single words
been reinforced, so the infant desired object while vocalizing take on multiple meanings and no
now begins to use them appropri- (eg, “uh...uh”). Next, the infant longer simply label an object.
ately. Infants next recognize and uses the object as a tool to obtain The infant usually does not com-
understand their own names and the parent’s attention (protode- bine words into true phrases or
the meaning of “no.” This marks clarative pointing). Protodeclara- sentences until he or she has
the beginning of exponential tive pointing is a social act; the acquired an expressive vocabu-
growth in receptive language. parent is an active and important lary of approximately 50 words.
By 12 months of age, some partner in a shared world. Rather Early word combinations are
infants understand as many as than acquisition of the object, the “telegraphic” in that they do not
100 words. They also can follow infant’s goal becomes the parent’s contain function words (preposi-
a simple command as long as the acknowledgment of the interest- tions, pronouns, and articles).
speaker uses a gesture. Early in ing object. For example, when an They do, however, convey the
the second year, a gesture no infant hears an airplane overhead, same meaning as the more
longer is needed to aid in com- he or she points to it and vocal- mature sentence. For example,
prehension of the command. izes to get the parent to look at “Go out,” in the context of the
Expressive language progresses it. If the parent does not comply situation, conveys the same
at a somewhat slower rate. The with these initial efforts, the meaning as “I want to go out-
infant will say at least one “real” infant may approach the parent side.” Telegraphic speech is the
word (ie, other than mama, dada, and turn his or her face toward first stage in the child’s ability to
or a proper name) before his or
her first birthday. At this time,
the infant also will begin to Word combination begins approximately 6 to 8 months
verbalize with sentence-like after an infant says his or her first words.
intonation and rhythm (immature
jargoning). As the expressive
vocabulary increases, real words
are added (mature jargoning). the plane in a more determined “grammaticize” speech, that is,
By the end of the naming period, effort to obtain what is some- to form sentences with proper
the infant will use approximately times called “joint attention.” morphology and syntax. At this
25 words spontaneously. Finally, the infant will point at an point in development, a stranger
During this period, pointing object and vocalize (“uh?”) in an should be able to understand at
becomes important to both effort to obtain the proper label least 50% of the infant’s speech
receptive and expressive language or name for that object from the (intelligibility). Language blos-
skills. Pointing already has listener. This is called “pointing soms after 2 years of age.
become a method of exploration for naming.”
within the problem-solving 3. Word Combination Period (18 to RED FLAGS IN COGNITIVE
domain. The infant beginning to DEVELOPMENT
24 months): Typically, children
look in the general vicinity where begin to combine words approxi- Language development provides the
the adult is pointing is a receptive mately 6 to 8 months after they clinician with an estimate of verbal
language skill. This ability is say their first word. If word com- intelligence; skill development in the
facilitated by the infant’s new binations appear much earlier, problem-solving domain provides an
realization that objects have they are likely “giant words.” estimate of nonverbal intelligence. If
labels. Later, the infant begins to Giant words are two- or three- deficiencies are global (ie, skills are
take part in pointing games. He word combinations that the infant delayed in both domains) and signif-
or she will point first to family hears frequently, such as “Thank icant (ie, >2 standard deviations
members, then objects, body you,” “Stop it,” or “Let’s go.” below the mean), there is a possibil-
parts, articles of clothing, and When the infant says one of ity of mental retardation. Mental
pictures upon request. These all these, he or she really is treating retardation refers to significant sub-
reflect receptive language skills. the phrase as a polysyllabic sin- average general intellectual function-
Pointing also is used for gle word. At this stage of devel- ing as measured by standardized
language expression. First, the opment the infant does not use tests. By current definition, these
infant points at an object and either word separately or in novel deficits must be associated with sig-
uses the adult as a tool to retrieve combinations with other words. nificant deficits in adaptive function-
the object, referred to by linguists “Holophrases” also are beginning ing. About 3% of the population is
as protoimperative pointing. The to appear at this time. For exam- mentally retarded. If the deficiencies
infant first points to the object ple, an infant may point to a are very mild (ie, in the low range
(eg, a cookie) and then looks mother’s keys and say “mommy” of normal), the child is considered
back and forth between the adult instead of saying “keys.” In to be of borderline intelligence or
and the object expectantly. At a this context, the single word, a “slow learner.”
later stage, he or she directs “mommy,” has a sentence-like When a discrepancy exists
attention to the adult and alter- meaning, such as “These keys between problem-solving and lan-
Pediatrics in Review Vol. 18 No. 7 July 1997 237

15. CHILD DEVELOPMENT
Infancy
guage abilities, with only language netic resonance imaging (performed with his or her receptive skills. A
being deficient, one must consider because of atypical head growth or child who speaks in five-word sen-
the possibility of a hearing impair- because of a known cerebral insult) tences but does not understand sim-
ment or a communication disorder. indicate that the child is at risk for ple commands is at risk of having a
If either language or problem-solv- intellectual deficits. pervasive developmental disorder.
ing skills is deficient, the child is at Although a cognitive deficit is The advanced speech may not be
high risk for manifesting a learning the most common reason for lan- functional or have communicative
disability later. A learning disability guage delay, all children who have intent. Finally, some parents will
refers to academic achievement that delayed language development excuse their child’s lack of speech
is substantially below what would should receive audiologic testing because of an “Uncle Albert” who
be expected from a person’s general to rule out hearing loss. The child didn’t speak until he was 4 years
intellectual potential. Approximately who has a hearing loss will demon- old but grew up to be a rocket
5% to 7% of school-aged children strate normal expressive language scientist. In reality, this is very
have learning disabilities. A learning skills through the babbling stage rare. Normal receptive language
disability cannot be diagnosed for- (6 months). He or she will begin to skills in a child who has speech
mally until the child reaches school babble on time, but lack of auditory delay would be reassuring and
typically are easy to demonstrate.
Other problems may masquerade
. . . all children whose language development is delayed as cognitive delay or impair the
should receive audiologic testing. assessment of cognitive abilities.
Problem-solving tasks require intact
fine motor skills. Having poor fine
motor skills puts the child at a dis-
age and demonstrates an inability to reinforcement for these vocalizations
advantage with certain manipulative
keep up in one or more academic results in their disappearance and a
tasks used to assess nonverbal cog-
areas. Thus, a reading disability can- general decline in verbal expression.
nition. Due to cerebral palsy, a child
not be diagnosed until at least age Receptive language abilities con-
may not be able to place a square
6 or 7 years when children normally tinue to progress normally for a few
are expected to read. A delay in lan- more months. A 1-year-old who is form in a form board; however, he
guage development is a “red flag” deaf will follow a command with or she might be able to indicate the
and should prompt careful monitor- a gesture (relying solely on the correct position by pointing or by
ing and further evaluation if the gestural cue) and may seem to hear. eye gaze. Thus, the child actually
child later demonstrates reading This ability to use environmental could “pass” the form board item in
difficulties in school. The neurologic cues can fool parents and profes- the problem-solving assessment.
substrate for specific learning dis- sionals and is one of the chief Similarly, visual impairment can
abilities involves patchy dysfunction reasons that the average age of interfere with a child’s ability to
in cortical information processing diagnosis of a severe hearing loss is perform many problem-solving
that results in specific difficulties 2 years. Children who have a mild tasks successfully.
with academic tasks. hearing loss will present even later
Unless the deficiencies are with articulation errors, inability to
severe during infancy, a child rarely localize sounds, or “attentional prob- Psychosocial Development
presents with a parental concern of lems.” An infant who is deaf will Emotional, social, and adaptive
“cognitive delay.” Concerns usually attempt to communicate by using milestones have been assimilated
present as speech delays, but such gestures. If a child has delayed from multiple sources (Table 4).
complaints are infrequent before speech and fails to demonstrate a These milestones are more variable
24 months of age. The average age desire to communicate, a more than those in motor and cognitive
at which mental retardation is diag- pervasive problem, such as autism, domains because of the greater
nosed is 3 to 4 years. Usually, the should be considered. Although chil- influence of environmental factors
more severe the degree of impair- dren who have autism may demon- (nurture). An infant inherits a set of
ment, the earlier the diagnosis is strate protoimperative pointing emotional-social characteristics and
made. Because the majority of chil- (eg, pointing to obtain food or drink), a style of interacting, but these are
dren who are mentally retarded are they rarely point to the object for the modified by parenting style, “good-
in the mild category, most children purpose of having the adult join in ness of fit,” and the social environ-
are diagnosed well after infancy. the pleasure of admiring an interest- ment. Emotions include the infant’s
Some are not diagnosed until they ing object (protodeclarative point- feelings as well as the expression of
enter school. The child who is born ing) or point to obtain the name of these feelings. Social milestones
with dysmorphic features and has a an object. Prodeclarative pointing is include the steps necessary to form
recognizable syndrome known to be a social action, and one of the cardi- interpersonal relationships. Tempera-
associated with mental retardation nal features of autism is the lack of ment influences social relationships
will be diagnosed earlier regardless social relatedness. Another red flag and generally reflects a consistent
of the degree of impairment. Addi- is the finding that a child’s expres- pattern (or style) in “how” a child
tionally, abnormal findings on mag- sive skills are advanced compared reacts. It is different from the
238 Pediatrics in Review Vol. 18 No. 7 July 1997

16. CHILD DEVELOPMENT
Infancy
TABLE 4. Psychosocial Development
AGE IN
MONTHS EMOTIONAL SOCIAL ADAPTIVE RED FLAGS
1–3 Interest Understands relationships State regulation Irritability
Disgust between voices and faces Requires only one Sleep/eating disturbances
Distress (pain, hunger) Bonding (parent → infant) night feeding
Enjoyment (social smile) Smiles reciprocally
Follows moving person
with eyes
3–6 Anger Recognizes mother Absent smile may
Happiness Attachment (infant → parent) indicate visual loss,
Joy Anticipates food on sight attachment problems,
Pleasure Smiles spontaneously or maternal depression
Sadness
Displeasure
6–9 Personality unfolds Discriminates emotional Gums/swallows cracker Absent stranger anxiety
Fear facial expressions and Places hands on bottle may be due to multiple
reacts differently Takes solids well care providers
Preference for a given Finger feeds dry cereal (eg, NICU care)
person
Stranger anxiety
Understands means-to-an-end
relationship in social
interactions
(act→clap →repeat act)
9–12 Assertiveness Differential fear response Holds bottle
Cautiousness based on gender and age Holds, bites, chews
Concept of self cracker/cookie
Social interactions become Drinks from cup held
intentional and goal-directed for him or her
Separation anxiety
12–15 Shyness Solitary play Cooperates with dressing
Empathy Begins formation of Drinks from cup;
Sharing relationships some spillage
Self-comfort • Love Removes socks/hat
(eg, attachment • Friendship
to blanket) • Acquaintance
• Strangers
Offers ball to mirror image
Kisses by simply touching
lips to skin or licks
15–18 Shame/guilt Self-conscious period; Uses spoon; some Lack of social
Contempt “coy” stage spillage relatedness may
Hugs parents indicate autism
18–21 Associates feelings First application of attributes Drinks from cup
with verbal symbols to self (eg, good, little, without spilling
Begins to have thoughts naughty) Moves about house
about feelings Initiates interaction by calling without adult
to adult Emerging independence
Kisses with a pucker Removes a garment
21–24 Beginning “socialization” Imitates others to please them Replaces some objects Persistent poor transitions
of emotional expression Recursive nature of social where they belong may indicate a pervasive
by social/cultural thought (ie, thinking about Uses spoon well developmental disorder
influences “How I behave to you Opens door by turning
• modulation of emotion and you to me”) knob
• masking of emotion Parallel play Removes clothes without
Infant’s reaction to Tolerates separation; buttons
ambiguous events is will continue activity Unzips zippers
shaped by emotional Puts shoes on part way
reactions of others
Pediatrics in Review Vol. 18 No. 7 July 1997 239

17. CHILD DEVELOPMENT
Infancy
“why” (motivation) and the “what” then can evoke feelings identical is negative, then other relationships
(content) of social interactions. to those experienced previously. will be poor. If it is positive, then
The inclusion of adaptive skills Thus, language and cognition add future relationships will be good.
(ie, skills required for independence flexibility and complexity to The Social Network Model recog-
in feeding, dressing, toileting, and emotional behavior. nizes the relative importance of
other activities of daily living) is The expression of emotions also the mother-child relationship, but
unique to the discussion of psycho- evolves with age and developmental also recognizes the ability of other
social development and reflects advancement. Consider this example relationships to compensate for
the concept that these skills influ- of an emotional reaction (fear) to a absent or poor mother-child interac-
ence, and are influenced by, social stranger, based on skill level: tions. The devastating effect of a
factors. poor relationship can be overcome
9 months by adequate substitutes and a sup-
EMOTIONAL DEVELOPMENT Cries and turns head away portive environment. The latter
Emotions are present in infancy and (mass body reaction) reflects the popular concept of
motivate expression (pain elicits and (avoidance reaction) childhood resiliency.
crying). Emotion has three elements: 24 months Social milestones begin with
neural processes, mental processes bonding, which reflects the feeling
Runs away of the caregiver for the child.
(feelings), and motor expression (motor development)
(facial, verbal) and actions. Emo- Attachment takes place within a
tions are mediated through the lim- 48 months few months and represents the
bic system, which is responsible for feeling of the infant for the care-
Says “Go away” or “Help”
receiving, interpreting, and process- (language development); giver. These social relationships
ing emotion-producing stimuli and or tries to alter the threat are manifested by the evolution
then initiating and modulating emo- (cognitive development) of the smile, in which the level of
tional responses. There is evidence stimulus required to elicit reciprocity
that an infant can express emotion In addition to developmental decreases. At first, high-pitched
without direct cognitive mediation. progress, the feedback loop between vocalizations and a smile from the
An infant who has anencephaly or care providers and child modifies adult are needed; later, a smile alone
hydranencephaly may show disgust emotional expression. Social forces is successful. When recognition of
and attachment to a familiar care-
giver develops, the simple sight of
Socioemotional milestones at 52 weeks include offering this person (smiling or nonsmiling)
will elicit a smile. The infant also
a ball to a mirror image and cooperating in dressing. becomes more discriminating in
producing a smile as he or she
begins to differentiate between
at sour flavors and interest in sweet and cultural factors also modulate familiar and unfamiliar faces. As
flavors in ways very similar to a emotional expression to produce the infant acquires the concept of
normal infant. Later, in the normal more restrictive and controlled facial causality, he or she begins to use
infant, these instinct-like reactions signals. An older child may learn smiling to manipulate the environ-
are modified by cognition. Although to modulate the expression of pain ment and satisfy personal needs.
emotional feelings are constant over (a facial grimace only) and appear Later in infancy, other social
the life span, their causes change quite stoic. Furthermore, children relationships are established. Several
and become more abstract. The can learn to mask emotions such behaviors are necessary for the
infant may show disgust for a bitter as smiling at a disappointing gift. development of these relationships.
taste; the older child may show At early stages, however, the true First, the infant must have a concept
disgust for a revolting idea. Other emotion typically leaks out from of self versus others. Next, he or
emotions have a definite cognitive under the mask. she must be able to put self in the
foundation. To experience fear, place of another, that is, to show
the 7- to 9-month-old child must SOCIAL DEVELOPMENT empathy. The infant must perceive
be able to shift attention, compare, The infant is surrounded by a social a separate identity with a different
and recognize “familiar” from network. Sensory processing is set of needs. He or she must realize
“unfamiliar” in the development influenced by the infant’s social the consequences of his or her inter-
of stranger anxiety. As the child needs. The infant has greater dis- actions on others. Empathy is criti-
develops, the interrelationship crimination ability for social voices) cal to forming a relationship. Next
between emotion and cognition than for nonsocial (environmental the child must be able to share,
becomes increasingly complex. noise) stimuli. There are two pri- which is critical to maintaining a
When the child begins to associate mary theories: the Epigenetic Model relationship. There are four basic
language symbols with emotions and the Social Network Model. In types of relationships: with acquain-
and memory, he or she can remem- the Epigenetic Model, the mother- tances, strangers, friends, and loves.
ber prior emotional experiences. child relationship is considered to Whereas relationships with acquain-
A verbal reminder of the event be all important. If this relationship tances and strangers simply require
240 Pediatrics in Review Vol. 18 No. 7 July 1997

18. CHILD DEVELOPMENT
Infancy
a concept of self, friendship and that do not reflect his or her true parents or an excessive emphasis
love require all three (a concept of abilities. on cleanliness.
self, empathy, and sharing). About
the same time that the child can ADAPTIVE SKILL DEVELOPMENT Conclusion
label emotions (via language), he Adaptive skill development is influ-
or she begins to think about social The journey through infancy truly is
enced by the infant’s social environ- fascinating—a time of incomparably
interactions. A child will demon- ment, as well as by motor and cog-
strate recursive social thoughts, that rapid changes in physical growth
nitive skill attainment. A child who and motor development. By the end
is, show early signs of thinking has quadriparesis may not be able to
about how others behave toward of this period, the child is mobile
feed him- or herself, even with nor- and explores his or her environment
him or her and how he or she mal intelligence and a supportive
behaves toward others. independently. The child’s pincer
social environment. grasp and release rival that of the
Temperament, or the infant’s In contrast, acquisition of self-
overall style of reacting, can affect adult. Cognitive and social changes
help skills by an able-bodied infant are equally prodigious. The baby has
social relationships. The precise may be delayed in the face of men- progressed from simple methods of
definition of temperament is contro- tal retardation and the lack of moti- expression (crying and grimacing) to
versial, but it generally is believed vation to become independent. In a “little person” who has a complex
to represent the characteristic style spite of normal motor and cognitive array of emotional expressions that
of a child’s emotional and behav- skills, an infant may demonstrate are becoming “socialized.” He or
ioral response in a variety of situ- delays in adaptive skills when social she has learned to use these emo-
ations. It is determined by genetic support and encouragement are lack- tions to manipulate the environment
factors but is modified by environ- ing. This is exemplified by delays and obtain the attention and the
mental forces. Temperament shows in self-feeding skills when the care- objects that he or she desires. Addi-
considerable stability over time. giver is overly concerned about tionally, the child can think about
Thomas and Chess describe nine messy spillage or feels the need to emotions and feel empathy for the
traits that determine whether rush mealtime. Additionally, parents emotions of others. He or she has
a child will have an “easy,” may persist in dressing the older strong love and friendship relation-
“difficult,” or “slow-to-warm-up” child in an effort to rush to child ships with family members and a
temperament: care. The decision to initiate toilet few significant others. The next few
1. Activity level—proportions of training often is influenced by both years are characterized by exponen-
family and culture. tial language development, which
periods of activity to inactivity
will reveal the complex thoughts,
2. Adaptability to change RED FLAGS IN PSYCHOSOCIAL feelings, and humor owned by this
3. Positive or negative mood DEVELOPMENT amazing creature destined to become
4. Intensity of emotional responses Decreased rhythmicity (eg, colic) an adult.
5. Rhythmicity of biologic functions may be an early indication of a
6. Persistence in the face of “difficult child.” Delay in the SUGGESTED READING
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Pediatrics in Review Vol. 18 No. 7 July 1997 241

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242 Pediatrics in Review Vol. 18 No. 7 July 1997