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Part Two

Infancy

Chapter 5: Physical and Cognitive Development in Infancy: First Excursions

Chapter 6: Social and Emotional Developmental in Infancy: Little Forays

Chapter

“I cannot abide that passion for caressing new-born children, which have neither mental activities nor recognizable bodily shape

by which to make themselves lovable, and I have never willingly suffered them to be fed in my presence.”

—Michel de Montaigne Essais

How dramatically Montaigne’s sixteenth-century attitudes clash with those of our times! And how strenuously might today’s mother defend the mental activities and the appearance of her child! Which is not to say that the newborn infant is capable of the sorts of mental feats that

might be involved in pondering problems of quantum physics or Boolean algebra. Not likely.

You see, the world is an amazing, bewildering, and largely unfamiliar place for the newborn.

Much of the business of growing up is a matter of becoming familiar with things. That is

mostly what occupies the first two years of life: becoming familiar with breasts and bottles,

with cups and cats, with doors and dragons; learning when to cry, when to be afraid, when

to laugh and smile; learning about mothers and fathers, and about strangers too; and learn-

ing to speak. This is what the next two chapters are about.

While reading these chapters, keep in mind that the infant, whom Montaigne would not

suffer to be fed in his presence, is a real person and not just a compilation of science’s hard-

earned facts and speculations. Try to remember—or at least to imagine—some of the feel-

ings of being an infant. Is the world bewildering and frightening? Exciting and marvelous?

Astonishing and delightful?

Chapter 5

Physical and Cognitive Development in Infancy: First Excursions

Focus Questions 1. How important

is nutrition for a newborn?

2. What are some important physi- cal and intellectual characteristics of neonates?

3. What can a newborn see? Hear? Smell? Taste? Feel?

4. Can newborns think? 5. How can an infant

manage to learn something as compli- cated as a language?

Chapter Outline

5.1 Nutrition, Growth, and Survival in Infancy Breast-feeding Nutrition and Physical Growth Sudden Infant Death Syndrome

5.2 Brain Growth and Motor Development Brain Structure and Development Motor Development in Infancy Motor Skill Disorders

5.3 Sensation and Perception in Infancy Vision Hearing Smell, Taste, and Touch

5.4 Memory in Infants Studying Infant Memory Characteristics of Infant Memory

5.5 Infant Cognitive Development Intention, Imitation, and Morality in Young

Infants Adaptation and Information Processing in

Piaget’s Theory Sensorimotor Development

5.6 Early Language Development The Prespeech Stage of Language

Development The First Word Three Explanations for Language Learning

5.7 From Sensation to Representation Section Summaries

Focus Questions: Applications

Possible Responses to Thought Challenges

Study Terms

Chapter 5

“. . . but as he’d gladly tell you, his mother had dropped him on his head when he was a baby, and half his wits had leaked out through his ear.” —George R. R. Martin, A Storm of Swords

Owen of the Night Watch isn’t the only baby to ever be dropped on his head, al-though most wouldn’t gladly tell you that’s why they’re half-witted. Like Owen, my friend Georgiou gained considerable notoriety through school by claim-

ing he had lost an enormous allotment of brain power as a result of the midwife’s accidentally letting him slip through her fingers when he was fresh born and still slick as an eel, and his landing smack on the top of his head.

“I couldn’t save myself,” he claimed, “though my mother said I tried.”

Georgiou is now a university professor. “There’s no telling what he might have been,” said my grandmother, “had he not been so helpless when the midwife dropped him.”

Nutrition, Growth, and Survival in Infancy Chapter 5

5.1 Nutrition, Growth, and Survival in Infancy Even if they are never dropped on their heads, in the beginning, infants are seemingly very poorly equipped for life’s journey. They are almost completely helpless physically: They can’t move somewhere else, control ambient temperature, or clean themselves; and they have no protection against wild dogs, vultures, one-eyed cats, or clumsy caregivers. They can’t even find food unless it is put under their very noses. Once they find it, though, they suck. Sucking is a primitive reflex—one of those simple, automatic, unlearned behaviors—present at birth in virtually all mammals.

Breast-feeding

The sucking reflex is what ensures the infant’s survival—that and the presence of a lactating mother. In fact, physicians pretty well universally recommend that the infant needs nothing other than a lactating mother for six months or longer (Breastfeeding, 2011).

But it seems that for many years there has been a quiet battle over breast-feeding—a breast versus bottle battle. On one side are the mothers who, for a variety of reasons, choose not to breast-feed their infants. On the other are a legion of physicians and philosophers. Their arguments for breast-feeding have varied through history. In early times, many insisted that breast-feeding is something all animals do; it is therefore natural and good. Others appealed to religion and duty, convinced that suckling is the child’s sacred birthright and the moth- er’s solemn duty. Still others believed that maternal virtues and morals might be transmitted through breast milk (Kessen, 1965). (So, do the virtues and morals of cows get transmitted through cow’s milk?)

More recently, physicians invoke an impressive list of medical reasons to support their recom- mendations. Mothers’ milk, science tells us, is the best of foods for most newborns. It contains just about the right combination of nutrients, the near-exact proportion of fats and calories, the almost-perfect assortment of minerals and vitamins. Furthermore, it is easier for infants to digest than cow’s milk, and less likely to lead to allergic reactions. Also, it provides infants with a high degree of immunity against many infections and diseases, and especially against diar- rhea, one of the principal causes of infant mortality in the developing world. The breast-fed infant’s increased immunity is apparent in greater resistance to a variety of diseases, including cancer and respiratory diseases (Melendi et al., 2010). And, not least important, human milk contains nutrients that are essential components of tissues such as the brain and the retina (Singhal et al., 2010).

Though most of the arguments for breast-feeding have emphasized its benefits for the fetus, there are also strong arguments to be made for its positive effects on the mother. Among them is the fact that the hormone, oxytocin, released during breast-feeding, is highly effective in preventing postpartum hemorrhaging, and in stimulating the return of the uterus to a non- pregnant state (termed involution). In addition, breast-feeding typically delays menstruation. This helps the breast-feeding mother retain essential iron stores and also serves as a natural means of spacing pregnancies. Whereas non-breast-feeding mothers may become pregnant again as soon as 6 weeks after delivery, extremely few lactating mothers can become preg- nant for at least 6 months. In addition, breast-feeding is linked with reduced risk of breast, uterine, and ovarian cancers; it is associated with weight loss; it lessens osteoporosis; and it may have a variety of psychological benefits (Dermer, 2001). It is also considerably less expen- sive than formula feeding.

Nutrition, Growth, and Survival in Infancy Chapter 5

In spite of the many advantages of breast-feeding, it is far from universal (Figure 5.1). And there are many valid reasons why a mother might choose not to breast-feed her infant, includ- ing painful breasts, infants rejecting the breast, and a variety of commitments typical of today’s busy mother. Also, bottle feeding allows fathers to be more intimately involved in the care of their infants.

◀ Although there are circumstances under which an infant might fare better with milk from a goat, physicians are pretty well unanimous in their conviction that mother’s milk is the best of all possible forms of nutrition for the infant.

FIGURE 05.01

Percentage of U.S. infants who were breast-fed

Ra ce

o f m

ot he

0 20 40 60 80 100

Mexican American

Non-hispanic black

Non-hispanic white

Total

30 and older

Age of mother

20–29

Under 20

Figure 5.1: Percentage of U.S. Infants Who Were Breast-fed

Note that the percentage of mothers who breast-fed their infants increases significantly with the mother’s age. Source: U.S. National Center for Health Statistics (2008), NCHS Data Brief, Breastfeeding in the United States. Findings from the National Health and Nutrition Examination Surveys: 1999. No. 5.

Nutrition, Growth, and Survival in Infancy Chapter 5

It would be misleading not to emphasize that in much of the industrialized world, where sanitation and nutrition are excellent, bottle-fed infants thrive. Also, it is worth noting that breast milk is affected by the mother’s intake of food and drugs, as well as by chemicals to which she is exposed. Alcohol, nicotine, barbiturates, stimulants such as caffeine, sedatives, and prescription drugs can each have an effect on breast-fed infants. There is evidence that HIV infections can sometimes be transmitted to the infant through breast-feeding (Kourtis & Bulterys, 2010). Though some of these may be poor reasons not to breast-feed, it appears that there are circumstances under which an infant’s journey might start out much better if fueled with milk from a cow or a goat or a prepackaged formula.

Nutrition and Physical Growth

Physical growth in infancy is relatively predictable, given adequate nourishment (Figure 5.2) In contrast, malnutrition, both in the prenatal and early postnatal periods, often leads to growth retardation and maturational delays (Martorell, 2010). Note that malnutrition is not synony- mous with starvation and hunger. It involves not getting the right combination of vitamins, minerals, and other nutrients, and can therefore occur even when there is plenty of food.

Because of our different genetic programs, identical nourishment will not make all infants exactly the same at all ages. Some will be very close to the averages shown in Figure 5.2; oth- ers may be well above or below average.

How much below average is a cause for concern? The somewhat arbitrary answer is in approx- imately the bottom 2.27 percent. Children who are in the bottom 2.27 percent for height are, by

FIGURE 05.02

5 100 15

Average weight in pounds

20 25 30

Newborn

2 months

4 months

6 months

8 months

10 months

1 year old

14 months

16 months

18 months

20 months

22 months

2 years old

Figure 5.2: Average Weight for U.S. Infants from Birth to Age 2

The actual weight of a given child may be very different from these averages. Source: Disabled World. Retrieved August 24, 2011, from http://www.disabled-world.com/artman/publish/height-weight-teens.shtml

http://www.disabled-world.com/artman/publish/height-weight-teens.shtml

Nutrition, Growth, and Survival in Infancy Chapter 5

definition, suffering from stunting; wasting is defined as being in the bottom 2.27 percent for weight. Sadly, in the world’s developing coun- tries, more than 32 percent of children under age 5 are classified as stunted (Progress for Children, UNICEF, 2011) (Figure 5.3).

The World Health Organization estimates that well over half of all children born in third-world countries suffer from malnutrition. Most seri- ous is protein undernutrition, which may have long-term negative effects not only on physi- cal growth, but also on cognitive function- ing. Serious protein deficiency in infancy is sometimes evident in the condition labeled kwashiorkor. In serious cases, kwashiorkor is marked by extreme wasting and stunting, listlessness, unresponsiveness, and sometimes death. In less severe cases, its effects are appar- ent in smaller physical size as well as in cognitive deficits later in childhood (Galler et al., 2010).

Malnutrition is far less common in industrial- ized countries despite significant numbers of mothers and children livingin poverty and many children not having enough to eat. Although few of these children suffer from kwashiorkor, many might be more likely to reach their full human potential, not to mention have hap- pier journeys through life, if their bellies were always as warm and full as they should be.

Sudden Infant Death Syndrome

First formally defined in 1969, sudden infant death syndrome (SIDS) is the sudden and unexpected death of an infant who has seemed well, or almost well. This mysterious cause of infant death accounted for approximately 1.5 deaths for every 1,000 live births as recently as 1980. Now that figure has been reduced to less than 1 per 1,000 (Chang, Keens, Rodriguez, & Chen, 2008).

Although research hasn’t yet determined the precise causes of SIDS, it has identified a number of characteristics shared by many victims. Most striking, SIDS occurs during a far narrower age span than almost all diseases: It is extremely rare in the first several weeks of life, peaks between 2 and 4 months, and falls rapidly to age 6 months. SIDS deaths are uncommon after the age of 1 year.

Other risk factors for SIDS include sex, with males accounting for about 60 percent of cases. There is evidence, too, that SIDS may be slightly more probable among infants whose siblings have been victims. Bundling infants in layers of clothing, maternal smoking, and bacterial infection are other possible related factors (Salihu, Hamisu, Wilson, & Ronee, 2007; Highet, Berry, & Goldwater, 2009).

FIGURE 05.03

Pe rc

en t o

f c hi

ld re

n un

de r fi

ve su

ffe rin

g fro

m m

al nu

tri tio

Stunting Wasting Underweight

Least developed countries

Developed countries

World

Figure 5.3: The Effects of Malnutrition in Nonindustrialized Countries

Stunting (bottom 2.27 percent in height), wasting (bottom 2.27 percent in weight), and being under- weight (below normal weight) affect more than one- third of the world’s children. Incidence is significantly higher in the least developed countries. Source: Based on data from The State of the World’s Children, 1998. Retrieved August 24, 2011 from

http://www.unicef.org/sowc98/tab2b.htm

Brain Growth and Motor Development Chapter 5

Perhaps most important for SIDS prevention is sleeping position. Infants who are put to sleep on their sides or on their backs (in a supine or face up position) are at far lower risk for SIDS than infants who sleep prone (face down, on their stomachs.) In fact, the reduction of SIDS deaths by more than one-third is attributed largely to medical advice to this effect (Dwyer & Ponsonby, 2009) (Table 5.1).

Table 5.1 Most Frequently Shared Characteristics of SIDS Victims

Characteristics Between 2 and 4 months of age

Male

Sleep prone (on their bellies)

Have a sibling who is a SIDS victim

Have mothers who are drug addicted

Have parents who smoke

Are premature infants

Have a history of respiratory or heart problems

Have a teenage mother

Were low birth weight

5.2 Brain Growth and Motor Development For many years, what we knew about the brain was based mostly on what had been dis- covered by looking at the brains of people who had died, or by looking at the behavior of people who had suffered brain injury. Now scientists have access to powerful brain-imaging techniques, such as functional magnetic resonance imaging (fMRI), which allow them to examine the physical structure and activity of intact brains in unobtrusive ways.

Investigations of brain development and activity reveal several important facts: For example, we know that the vast majority of the brain’s cells—more than 200 billion neurons—are formed during the first four months of prenatal development. And we also know that optimal brain development is influenced by two important factors: One is sensory and cognitive stimulation; the other is nutrition (Guerrini, Thomson, & Gurling, 2007). Protein and certain fatty acids (which are present in milk, especially human milk, but not ordinarily in infant formulas) are especially important to normal brain development during the prenatal period and in the first year of life (de Souza, Fernandes, & do Carmo, 2011). Deficiencies in iron, iodine, and vitamin A may also be implicated in poorer mental development (Melse-boonstra & Jaiswal, 2010).

During the final several weeks of fetal development, the absolute weight of the brain increases dramatically. At birth, the brain already weighs about one-quarter of what it will weigh at adulthood, whereas the newborn’s total weight is only about one-twentieth of what it will eventually be.

Brain Structure and Development

Although the brain is relatively large at birth (approximately one-quarter the size of the rest of the body, compared with an adult ratio of about 1 to 8 or 10), most of its billions of cells are not yet connected to each other—except for the brain stem, where networks of cells are programmed for activities such as breathing, sleeping, and temperature control.

Brain Growth and Motor Development Chapter 5

The very large brain of the newborn—and the adult—consists of three main parts (Figure 5.4). The brain stem, which is an extension of the spinal cord, is the most highly developed brain structure at birth. It deals mainly with physiological functions such as breathing and heart action. The cerebellum, a structure found low at the back of the brain behind the brain stem, is concerned with balance and with sensory and motor activity. The cerebrum is the largest and most complex brain structure. It divides naturally into two halves (brain hemispheres). Its outer covering, the cerebral cortex, is the convoluted and wrinkled grayish surface that would be immediately visible if the skull were opened.

The cerebrum makes up about 75 percent of the total mass of the brain, and its functions are among the most important in determining what it is to be human (thought, language, vision, and sensation). It is the most recent brain structure from an evolutionary point of view, and also the latest to develop in the fetus. Those parts of the cerebrum that are concerned with thought continue to grow and develop into early adulthood.

The cerebral cortex (the thin outer covering of the cerebrum) has deep fissures (indentations) that divide into four distinct lobes: the parietal lobes; the frontal lobes; the temporal lobes; and the occipital lobes. The main functions of these lobes are shown in Figure 5.4.

The major early developments in the brain have to do mainly with its system of interconnec- tions. The brain, as well as the rest of the nervous system, is composed of billions of neurons (nerve cells), whose function is to transmit impulses in the form of electrical and chemical changes. Transmission occurs through interconnections that form among neurons. Each neu- ron consists of a cell body, an elongated part (the axon) surrounded by a protective coat- ing (the myelin sheath), and hair-like extensions (dendrites). Neural transmission ordinarily

FIGURE 05.04

Parietal lobe (sensation)

Cerebrum

Occipital lobe (visual cortex)

Cerebellum (balance; motor coordination)

Frontal lobe (motor activity; higher through processes)

Temporal lobe (auditory cortex, language)

Brain stem (basic vital functions such as breathing and heart action)

Figure 5.4: Side View of the Human Brain, Facing Toward the Right

A right-side view of the brain stem, the cerebellum, and the cerebral cortex with its four lobes. Although the lobes are associated with the functions indicated, their functioning is highly inte- grated. © Thinkstock

Brain Growth and Motor Development Chapter 5

proceeds from the cell body outward along the axon, at the end of which the impulse (mes- sage) jumps the gap—termed a synapse—to the dendrites of adjacent neurons (Figure 5.5). Bundles of neurons make up nerves.

The brain continues to grow very rapidly during the first two years, reaching about 75 percent of adult weight at the end of that period. The very rapid development of the brain that occurs during this time does not involve the formation of new neurons, but rather the development of new connections among them—a process highly dependent on stimulation from experi- encing the world and from social interaction. What this brain proliferation means is that by the age of 2, the infant brain has an enormous number of potential connections among brain cells. These connections are what make it possible for 2-year-olds to learn so much so rapidly. And perhaps nowhere is the staggering potential of this brain more evident than in the learning of language.

Interestingly, the brain of the 2-year-old may contain more potential connections than it will ever contain again. It is likely, explains Johnson (2000) that the billions of connections that aren’t used eventually disappear—a process referred to as neural pruning.

The Role of Experience

This is where experience comes in. The human brain is extraordinarily dependent on experi- ences if it is to develop normally. It seems that in the absence of appropriate stimulation early in life, far more of these billions of connections will be lost than would otherwise be the case. Environmental events, such as exposure to language, are critical to the development of the brain (Fox, Levitt, & Nelson, 2010). This is clearly illustrated in experiments with animals. For example, Rosenzweig (1984) found that rats raised in enriched environments have signifi- cantly heavier brains than rats raised in impoverished environments. And kittens who are not

FIGURE 05.05

Dendrites

Cell body

Nucleus

Myelin sheath

Synapse

Axon

Figure 5.5: Illustration of the Main Parts of the Human Nerve Cell

Neural transmission ordinarily proceeds from the cell body, down the axon, and across the synapse to the dendrites of adjoining cells. © Thinkstock

Brain Growth and Motor Development Chapter 5

exposed to visual stimulation for the first several weeks of their lives (their eyes are sewn shut or they are blindfolded) lose most of the neural connections usually associated with vision and never learn to see normally (Hubel, 1988).

For ethical reasons, experiments such as these cannot be conducted with humans. However, measures of brain structure and functioning in a group of preterm newborns found significant benefits of enriched stimulation during the first two weeks of life (Als et al., 2004). Similarly, studies of Romanian orphans exposed to highly deprived environments during their first years reveal dramatic differences between their brains and those of normal children (Eluvathingal et al., 2006).

As a result of findings such as these, some researchers suggest that there are distinct periods of very rapid brain growth during which exposure to appropriate environmental stimulation is critical for later learning and the development of intelligence (Dawson, Ashman, & Carver, 2000). Not surprisingly, the most dramatic spurt in brain growth occurs early in the first year of life. That Genie Wiley, the abandoned child described in Chapter 3 and again later in this chapter, did not develop normal language skills after she was rescued may be evidence that there is a critical period during which exposure to language results in far more rapid and effective learning. It is as though there are certain paths that must be followed early in the journey or they may never be found again.

The Brain and Infant States

One of the important functions of the brain during early infancy is to control the infant’s gen- eral condition—that is, the infant’s physiological arousal or infant state. Following a detailed study of infant behaviors, Wolff (1966) describes six distinct infant states: regular sleep, irregular sleep, drowsiness, alert inactivity, alert activity, and crying (these last two states are sometimes grouped together and termed focused activity). Note that these are essentially descriptions of central nervous system activity. Newborns vary considerably in the amount of time spent in each state (Figures 5.6 and 5.7).

Motor Development in Infancy

Within hours of birth, beavers are able to dive, hold their breaths, and swim; young antelope can run with the herd; and baby geese can follow their mothers. These animals are precocial (born with highly developed motor capacities.)

In contrast, human infants are altricial (born relatively immature). They cannot walk or even control the movements of their hands or their heads. As a result, they remain physically help- less for a prolonged period of time.

Reflexes

In the very beginning, the newborn cannot initiate intentional behaviors, capable only of reflexes—simple, unlearned behaviors that are present at birth. In a sense, reflexes are automatic and essentially unavoidable reactions to stimulation. Some reflexes, such as the breathing reflex, the sucking reflex, and the rooting reflex are survival reflexes—as are swallowing, hiccuping, sneezing, and vomiting.

Brain Growth and Motor Development Chapter 5

Other reflexes, such as the moro reflex—a generalized startle reaction that involves throw- ing out the arms and feet symmetrically—have no apparent survival value today. However, some speculate that this reflex might have saved the lives of unlucky tree-dwelling primate infants who fell unexpectedly. In normal infants it, like the palmar reflex (also called the Darwinian or grasping reflex), the swimming reflex, and the stepping reflex, disappears early in infancy—as does the Babinski reflex (Table 5.2).

The development of the infant’s early motor skills is closely related to early reflexes. Thus learning to crawl is an extension of the swimming reflex, just as learning to walk and learning to grasp are extensions of the stepping and the palmar grasp reflexes. Some of these motor accomplishments involve gross motor development (skills related primarily to large body movements such as crawling, standing, and walking). Fine motor development refers to the development of control over smaller (finer) movements (hence smaller muscle groups such as those involved in grasping and stroking).

Relative distribution of 6 newborn states

Description ResponsivenessState

Regular (deep sleep)

Irregular sleep

Crying

Alert inactivity

Alert activity

Drowsiness

5 8.3

33.3

Largely motionless, eyes closed, regular breathing No response to mild stimuliRegular (deep) sleep

Twitching motions, eyes closed, irregular breathing

Sounds or bright light can elicit grimace or cryingIrregular sleep

Moderately active state precedes or follows sleep; eyes may be closed or open Responsive to stimuliDrowsiness

Relative inactivity, eyes open, breathing more rapid than regular sleep,

examining environment

Highly responsive; maintains examination of worldAlert inactivity

High activity, eyes open, rapid breathing

Moderate responsiveness to stimuliAlert activity

Figure 5.6: Relative Distribution of Six Newborn States

The infant’s state reflects level of alertness or responsiveness to the environment. States are closely related to the infant’s level of brain activity (arousal). Source: Based on Wolff, 1966.

Brain Growth and Motor Development Chapter 5

The order in which children acquire motor skills is highly predictable, although the ages at which these skills appear can vary considerably. Descriptions of developmental milestones and norms, such as shown in Figure 5.8, are sometimes useful for assessing a child’s progress. However, as always, there is no “average” child; each is unique.

The normal sequence of motor development reflects two broad developmental principles: First, development is cephalocaudal—meaning it proceeds from the head toward the feet. For example, infants can control eye movements and raise the head before acquiring control over the extremities. Fetal development proceeds in the same manner in that the head, eyes, and internal organs develop in the embryo before the limbs appear.

Second, development is proximodistal (near to far): it proceeds in an inward-outward direction. For example, internal organs mature and function before the (more external) limbs develop. Similarly, children can control gross motor movements before hand or finger movements.

Cultural Variations

Although the sequence of early motor development reflects a genetically influenced time- table, the infant’s context can dramatically influence both the ages at which different motor skills are acquired and their quality. For example, Gerber (1958) reports an investigation of 300 Ugandan infants who, a mere two days after birth (all home deliveries without anes- thetics), could sit upright, heads held high, with only slight support of the elbows—a feat

FIGURE 05.07

Pe rc

en ta

ge o

f t im

e sp

en t s

le ep

in g

1 2 3

Infant

4 5 6

Figure 5.7: Brown’s Study of Infant Sleep

Brown observed six infants an hour after feeding, during their first week. Shown here are the tre- mendous variations in the amount of time each spent sleeping. Source: Based on data from J.L. Brown, 1964.

Brain Growth and Motor Development Chapter 5

that most American children cannot accomplish until close to the age of 2 months. And all 300 Ugandan children were expert crawlers before they were 2 months old (as opposed to between 6 and 9 months for American children)!

What accounts for these differences? A variety of factors, explains Adolph (1997). Genetic factors, perhaps reflected in the infant’s activity level as well as in distributions of muscle and fat, appear to be clearly important. For example, newborns with chubbier legs often learn to walk later than do those with more slender legs.

At the same time, however, experience is clearly important. Ugandan infants, many of whom are typically held upright and carried around by their mothers, may learn much about locomo- tion both visually and in terms of their bodily sensations of the mother’s movements. Similarly, children adopted from Eastern European orphanages often display markedly delayed motor development, a circumstance attributed to them being often left in their cribs or lined up on

Table 5.2 Some Reflexive Behaviors in the Newborn

Reflex

Stimulus

Response

Approximate age of appearance

Approximate age of disappearance

Sucking Object in the mouth Sucks 2–3 months in utero Becomes voluntary during first year

Rooting (head turning)

Stroking the cheek or the corner of the mouth

Turns head toward side being stroked

Neonate Becomes voluntary during first year

Swallowing Food in the mouth Swallows Neonate Becomes voluntary during first year

Sneezing Irritation in the nasal passages

Sneezes 4–6 months in utero Present in adult

Moro reflex Sudden loud noise Throws arms and legs out symmetrically

Neonate 3–4 months

Babinski reflex Tickling the middle of the soles

Spreads and raises toes

Neonate Diminishes by 1 month; disappears by 5–6 months

Toe grasp Tickling the soles just below the toes

Curls toes around object

4–6 months in utero Disappears by 9 months

Palmar grasp Placing object in the infant’s hand

Grasps object tightly

4–6 months in utero Weak by 8 weeks; gone by 4–5 months

Swimming reflex

Infant horizontal, supported by abdomen

Coordinated swimming movements

8–9 months in fetus Disappears after 6 months

Stepping reflex

Infant vertical, feet lightly touching flat surface

Makes coordi- nated walking movements

8–9 months in fetus Disappears after 2–3 months

Brain Growth and Motor Development Chapter 5

benches for extended periods with little or no opportunity to practice the skills involved in locomotion (Judge, 2003).

Motor Skill Disorders

Not all children learn to walk or tie their shoes or dance as expected; some experience a vari- ety of physical and motor problems, sometimes evident in cerebral palsy and other conditions.

Cerebral Palsy

Cerebral palsy, also labeled significant developmental motor disability, is a nonpro- gressive, noncontagious condition reflected in motor problems that cause physical disability of varying severity. It may also include psychological problems, convulsions, or behavior disor- ders. It varies in severity from being so mild that it is virtually undetectable, to paralysis.

Cerebral palsy is most often a congenital disease—that is, it is present at birth in more than two-thirds of all cases. It is associated with brain damage—the reason for the label cerebral— although the damage is often mild and nonspecific. Sometimes it results from anoxia (lack of oxygen during the birth process, or before or after birth). It can also result from either maternal infection and disease or postnatal brain injury sometimes caused by diseases such as meningitis or encephalitis (Bjorklund, 2006). Not surprisingly, prematurity is a significant risk factor for cerebral palsy (McCormick, Litt, Smith, & Zupancic, 2011).

Figure 5.8: Major Milestones in Gross Motor Development

There is wide variation in the ages at which different children reach these milestones—and less than perfect agreement among researchers regarding the ages at which they are “normally” reached. © iStockphoto/Thinkstock; Photodisc/Thinkstock; iStockphoto/Thinkstock

FIGURE 05.08

2–3 4–6 7–9

Age in months

6–10 11–15

Lifts head 90° when prone Rolls over; sits with support Sits without support

Pulls self to stand; walks holding

furniture Walks alone

Sensation and Perception in Infancy Chapter 5

Cerebral palsy is the second most common devel- opmental disorder among school children in the United States (mental retardation is more com- mon). Estimates of its prevalence are imprecise because many of the milder cases are not reported and because there is no “cure” for the condition. In the United States, there are about 3 cases for every 1,000 live births. Of these, perhaps half also have other developmental disabilities (National Center on Birth Defects and Developmental Disabilities, 2004).

One of the most common signs of cerebral palsy is spasticity (inability to move voluntarily) in one or more limbs. Physical therapy is sometimes effective in improving motor control and coordination.

Language disorders are also relatively common. These motor and language impairments are some- times so severe that it is difficult to assess a child’s intellectual ability. As a result, it was often assumed that intellectual deficits are common among those suffering from cerebral palsy. However, more recent evidence suggests that fewer than half of cerebral palsy victims are mentally retarded (Mesterman et al., 2010).

Other Motor Skill Disorders and Physical Problems

There are other motor skills disorders not associated with brain damage or cerebral palsy. These are often evident in delayed development among children, many of whom also have other developmental disorders, such as mental retardation, autism, or even attention-deficit disorders. Motor disorders may be apparent in difficulties in learning tasks such as walk- ing, running, skipping, and tying shoes; they may also be apparent in difficulties in carrying out motor activities. A common label for these problems is developmental coordination disorder.

According to the Diagnostic and Statistical Manual of Mental Disorders (DSM-IV-TR) of the American Psychiatric Association, a developmental coordination disorder exists when (1) a person’s performance of activities requiring motor coordination (such as crawling, walking, sitting, handwriting, sports) is markedly below what would be expected for the child’s age, (2) the disturbance interferes with academic achievement or activities of daily living, and (3) the disturbance is not due to a known physical disorder (such as cerebral palsy) (American Psychiatric Association, 2000).

5.3 Sensation and Perception in Infancy Our journeys as human beings depend largely on our ability to make sense of the world and ourselves. We need to be able to sense and to know what is out there. The struggle to dis- cover what things are and what they mean begins in infancy and depends on three closely related processes: sensation, perception, and conceptualization.

▲ Cerebral palsy is a motor disorder that can be so mild to be almost undetectable or so severe that it is evident in paralysis. Cognitive abilities are some- times affected, but often not. © Tom Nebbia/Corbis

Sensation and Perception in Infancy Chapter 5

Sensation is the effect of physical stimuli on the senses; it involves activity of one or more specialized sense organs—eyes, ears, and taste receptors, for example.

Perception is the brain’s interpretation of sensation. We perceive the color red when wave- lengths corresponding to that color cause a specific reaction in our retinas, leading to the transmission of impulses to the part of our brain that deals with vision. Thinking about that color red, comparing it to other colors, or making some decision based on it is a function of the third process, conceptualization, which is a more cognitive or intellectual activity.

Because these three processes—sensation, perception, and conceptualization—are basic for understanding the world, knowing about their functioning and their development is impor- tant for understanding what infants experience.

Vision

How well can an infant see? Is the world fuzzy and blurred, or is visual acuity 20/20, making the world crisp and clear? Research with infants isn’t always easy (Figure 5.9), nor do research- ers always agree, but a number of things seem clear.

First, vision is probably the least well developed of the infant’s senses. Visual acuity, that is the sharpness of the newborn’s vision, is estimated to be about 20/400, or perhaps even 20/600 (they can see at 20 feet what people with normal vision see at 400 or 600 feet). Hence neonates’ visual worlds are somewhat fuzzy and blurred, although they are far from blind (Valenti, 2006) (Figure 5.10).

Second, there is roughly a five-fold improvement in an infant’s visual acuity by the age of 6 months (Courage & Adams, 1990). Now the infant sees as clearly at 20 feet what the adult sees at 100 feet. And by the age of 1 year, infant visual acuity is close to that of a normal

FIGURE 05.09

Number out of 90 potential newborn participants who responded as indicated

0 5 10 15 20 25 30 35 40

Were distracted by bowel movements

Fell asleep

Started to cry

Had bouts of spitting and choking

Completed the test

Figure 5.9: Why Infants Are Often Poor Experimental Subjects

When Fantz wanted to see how newborns reacted to visual stimulation, one of the most important conditions for selecting participants was whether they kept their eyes open long enough to be shown the stimuli. Only 37 of the 90 newborns actually completed an 8-minute test. Source: Based on Fantz, 1963.

Sensation and Perception in Infancy Chapter 5

adult. But it’s important to note that improvement in vision is highly dependent on early expe- rience. Stroganova and Tsetlin (1998) report that infants born with cataracts in both eyes experience significant developmental delays, even after the cataracts are surgically removed at around 8 months.

Third, a newborn’s visual accommodation is more limited than that of adults. It appears that newborns focus most accurately at a distance of approximately 8 to 12 inches (Banks, 1980). Significantly, that is about the distance of a mother’s face when she is feeding her infant.

Perception of Depth

In the famous Gibson and Walk (1960) “visual cliff” studies, a heavy sheet of glass is posi- tioned over a checkered surface, but only half of this surface is flush with the glass; the other half is some three feet lower (Figure 5.11). An adult standing or sitting on the glass can plainly see a drop where the patterned surface falls away from the glass. So can goats and human infants. At the age of only 1 day, baby goats avoid the deep side, either going around it or jumping over it when they can. And even when their mothers call them from the other side, human infants who are old enough to crawl typically refuse to cross the deep part. Thus per- ception of depth is present at least from the time that the infant can crawl.

Visual Preferences

We know that young infants see, although somewhat fuzzily in the beginning. We know, too, that they have limited perception of color for the first few months, but that they prefer bright colors over plain white (Zemach & Teller, 2007). Also, they are capable of detecting motion

Figure 5.11: The Visual Cliff

Use of a “visual cliff” apparatus demonstrates that infants perceive depth—and fear falling—at a very young age. No matter how hard she tries, this tyke’s mother is unable to coax her onto the glass surface. © SCIENCE SOURCE/Getty Images

FIGURE 05.10 Figure 5.10: Infant Vision

The face on the left is what a newborn might see. By the age of one, infants’ visual acuity is more similar to the image on the far right. © Guy Lefrançois

Sensation and Perception in Infancy Chapter 5

and of visually following moving objects very soon after birth. Do they also have preferences with respect to what they look at?

The answer is yes. In one study of infants’ visual preferences, 18 infants, aged 10 hours to 5 days, were shown six circular stimulus patterns of different complexity, the most complex being a human face (Fantz, 1963). The face was looked at for a significantly higher proportion of total time, indicating not only that infants can discriminate among the various figures, but also that they prefer faces—or perhaps that they prefer complexity.

Subsequent research suggests that infants are predisposed to attend to faces. And very soon, they show a distinct preference for the female face and for faces of their own ethnic origin. It seems, argue de Haan and Nelson (1997), that infants are born with some innate knowledge about faces that allows them to recognize and be attracted to them. They suggest that this pro- pensity is probably closely tied to the importance of recognizing primary caregivers if the infant is to form an attachment to them.

Hearing

Dogs, bears, cats, and many other animals are deaf at birth; the human neonate is not. It appears that the ear is fully grown and potentially functional a few months before birth, and that the fetus can hear sounds (Lecanuet & Schall, 2002). In fact, most investigations indicate that neonates are extraordinarily attuned to hearing human speech sounds and to discriminating among them. Amazingly, even at the age of 3 days, infants are able to discriminate among dif- ferent voices and seem to prefer the sound of the mother’s voice. In a study in which systematic changes in an infant’s sucking were reinforced with the sound of a woman reading

Thought Challenge 5.1

A man, known to us only as S.B., was born blind and stayed that way for the first 52 years of his life. The psychologist Gregory (1973) reports that he adapted very well during those years, and that he could often be seen riding about his village on a bicycle with his hand on a friend’s shoulder. He had also learned to build things in his workshop, and he spent much of his time trying to find out what the world looked like to sighted people.

Then, at the age of 52, he underwent a successful cornea transplant. Now able to see for the first time in his life, he quickly learned to identify those things with which he was most familiar. But he never developed any sense of perspective, of depth, or of speed. For example, he believed that he could easily lower himself to the ground from the ledge of his hospital window, even though it was more than 30 feet up. And he became terrified of crossing streets, although he had confidently done so all his life when blind. In the end, like many other individuals in similar circumstances, he became depressed, choosing to spend more and more time sitting at home in the dark. Some three years after he was given his sight, he died.

What is the most likely explanation for S.B.’s visual problems after regaining his sight?

▲ The discovery that the fetus can hear sounds has convinced some that they should read to their unborn children, or play soothing, classical music for them. Evidence that this might have beneficial effects later is still highly tentative. © Ragnar Schmuck/Corbis

Sensation and Perception in Infancy Chapter 5

a book, the infant responded most strongly to its mother’s voice (DeCasper & Fifer, 1980). By the age of 6 months, infants have not only learned to discriminate a wide variety of human sounds, but have also begun to assign meanings to many of them.

Smell, Taste, and Touch

Smell is one of the most important senses for the earth’s animal species. Without a powerful sense of smell—and of taste—most animals would be in grave danger of not finding food or of poisoning themselves. It should hardly be surprising that newborns are highly sensitive to odors, as well as to tastes and touch.

Within hours of birth, newborns turn their faces away when exposed to a strong and unpleasant smell such as ammo- nia (Lipsitt, Engen, & Kaye, 1963). And they smack their lips when sweet things are placed on their tongues and pucker their mouths in response to sour tastes. As grandmothers have long suspected, and as science has now confirmed, giving cry- ing newborns sucrose is often effective in quieting them; giving them lemon leads to an expression of distaste; and giving them plain corn oil or water has little effect (Graillon, Barr, Young, Wright, & Hendricks, 1997).

Earlier investigators had concluded that the neonate is remark- ably insensitive to much of the stimulation that children and adults would find quite painful. Circumcision doesn’t really hurt boy babies, they assured us. But they were probably at least partly wrong: Boy babies do holler when circumcised! And more recent research indicates that neonates are sensitive to pain (Fitzgerald & Walker, 2006). (See Concept Summary: Perception in Infancy).

Concept Summary: Perception in Infancy

Key Terms Explanation/Elaboration

Sensation—

Perception—

Conceptualization—

The physiological effect of stimulation on the sense organs

The brain’s interpretation of sensation

Conscious interpretation of the significance of perception; thinking

Infant Vision— World somewhat fuzzy at birth, with about 20/400 vision

Built-in accommodation for about 8 to 12 inches

Ability to perceive depth present before infant can crawl

Able to recognize and prefer faces, especially mother’s, within days of birth

Hearing— Present even prenatally

Able to recognize and prefer mother’s voice within days of birth

Smell, Taste, Touch— High sensitivity to odors

Preference for sweet tastes

Sensitivity to pain present in newborns

▲ The neonate is highly sensitive to odors and tastes. This little urchin’s expression says very clearly, “I don’t much like the taste of lemon!” © Sodapix/Thinkstock

Memory in Infants Chapter 5

5.4 Memory in Infants We know that infants are born with an impressive array of cognitive tools—tools that will eventually allow them to know and understand things of which they cannot yet even dream. They can look and see; they can hear; they can smell and taste. And more impressive than anything else, they have an astonishing brain. In fact, everything we have learned about infants thus far reinforces the view that they are remarkably ready to learn.

But ready though they might be, they know so little; there is so much to learn and so little time to do it if they are to be as competent at the age of 2 as most of them will surely be. How do they learn? What do they learn? How do they remember? What do they know in the beginning and what do they know at the end?

Studying Infant Memory

If neonates, ignorant and helpless as they are at birth, are ever to reach the level of compe- tence of the 2-year-old, there is much that must be organized and stored in their memory: They must learn and remember what is edible and what isn’t; how to get from here to there; how to ask for things; how to hold a cup; how to get people’s interest and attention; and much more.

A neonate’s memory does not appear to be nearly as efficient and powerful as yours or mine. Nor is it an easy thing to study, given that pre-verbal infants cannot easily tell the investigator what they remember.

The Orienting Response and Habituation

One way of investigating infant memory is to look at the orient- ing response—the tendency of most organisms to respond to new stimulation by becoming more alert—that is, by attending or orienting to it. In dogs, the orienting response is clear. On hearing a new sound, a dog will pause and its ears may perk up and turn slightly toward the sound; its attitude says, in effect, “What the %$*#@ was that?”

The human infant does not respond so obviously, but distinct and measurable changes take place, including alterations in pupil size, acceleration or deceleration of heart rate, and changes in the elec- trical conductivity of the skin. Together, these changes define the human orienting response.

The value of the orienting response is that it signals attention because it occurs only in response to novel stimulation to which the infant is then attending. It can also be used as an indication of learning because when an infant has learned a stimulus (when it has become familiar), the orienting reaction decreases or dis- appears—a phenomenon termed habituation. In a simple study of memory, for example, researchers might look at an infant’s response to a photograph (or other stimulus) presented on two different occasions. If the infant remembers something about an already-seen photograph, heart rate would not be expected to change in the same way as it initially did.

▲ Research with infants sometimes uses measures of physiological functions such as heart rate as an indication of learning and memory. Facial expressions and other bodily reactions can also serve as power- ful signals. But, as is evident here, they are not always easy to read. © Alexandra Falk/Corbis

Memory in Infants Chapter 5

When infants are older, memory can often be studied by looking at behaviors they can now control. For example, Rovee-Collier and Hayne (1987) report a study in which 3-month-old infants learned to make a mobile turn by moving their feet. Infants remembered the proce- dure several weeks later.

Characteristics of Infant Memory

Using these various approaches, investigators have found that even newborns have memories. For example, Swain, Zelazo, and Clifton (1993) had 1-day-old newborns listen to a word and then monitored them as they turned their heads toward the sound. Within a short period of time, these infants habituated to the word and stopped turning. One day later, half these infants were again exposed to the same word; the other half heard a different word. Again, all infants initially oriented to the word, turning their heads toward it. But those who were exposed to the same word both days habituated significantly more rapidly than those who heard a new word—clear evidence that they remembered something of the word.

Still, evidence suggests that an infant’s memory for most things appears to be relatively brief. Young infants who are conditioned to associate a puff of air with a tone, or a feeding sched- ule with a bell, may remember from one day to the next. But without any reminders in the interim, all evidence of memory is likely to be gone within a few days.

It seems clear that memories of very young infants are far more fragile than adult memories; they are far more likely to be lost. Yet, by the age of 18 months to 2 years, infants’ long-term memories are quite remarkable—as is evident in the fact that by that age, most have learned, and will remember, hundreds of words (Rovee-Collier & Cuevas, 2009). It’s true, however, that they will be reminded of these words repeatedly. And it’s also true that, in the end, they will consciously remember virtually nothing of any of the specific experiences they have had as children. In fact, we all seem to be victims of this strange phenomenon labeled infantile amnesia: Our early autobiographical memories (memories for personal experiences, tied to a time and place) are typically lost to infantile amnesia. Even 6-year-olds are hard pressed to

recollect memories they had clearly in mind two years earlier (Peterson, Warren, & Short, 2011).

There is, as yet, no agreed-upon explanation for this fact (Bauer, Larkina, & Deocampo, 2011). One theory is that parts of the infant’s brain associ- ated with memory are insufficiently mature to permit long-term remembering; another is that the infant’s memory strategies are too primi- tive to allow the organization and associations required.

There is a great gulf between the immature memory of the week-old child who can dem- onstrate a vague recollection of a familiar smell or sound, and that of the 1-year-old who mis- takenly yells “Dada” when he sees a stranger’s familiar-looking back in the supermarket. There is also a vast difference between this 1-year- old’s memory and the memory of an 8-year-old,

▲ The infant’s memory is not as powerful or well organized as yours or mine. It would be too much to expect that this urchin is reading music, or remembers the sounds associated with each key. But that he even recognizes the piano and remembers how to pound its keys is no small feat either. © Bernd Vogel/Corbis

Infant Cognitive Development Chapter 5

whose intellectual strategies permit mental feats the 1-year-old cannot even imagine. (See Chapter 7 for more information about memory.)

The infant’s rapidly developing memory makes possible a range of intellectual achievements that we, as adults, tend to take for granted. Memory, as Howe (2011) explains, is the basis of adaptation and survival. That I recognize my computer this morning, that I can anticipate the contents of this file before I open it, and that I can intend to say to you what I am saying at this very moment—none of these things would be possible if I had no reliable memory of these matters, or if I did not know that I can control the actions that will turn my intentions into realities.

Matters are not exactly so for young infants. Not only are they unable to control their actions, but they also have little understanding of intention, of how actions can deliberately be guided toward goals. Perhaps even more basically, they have yet to realize that objects in the world are real and permanent, that they have an independent existence.

5.5 Infant Cognitive Development As Piaget explains, infants have not yet developed the object concept. The world of the infant is a world of the here and now. The nipple exists when the infant sees, touches, or sucks it; when it can’t be sensed, it is gone from memory and has ceased to exist.

Imagine what the world would be like, suggest Wellman and Gelman (1992), if we thought objects disappeared and reappeared. The object concept, they explain, is absolutely funda- mental to our reasoning about the world; our very conception of the world demands that objects be real, out there, substantive, and independent of us. There is no “out there” for infants; they must discover the permanence and objectivity of objects for themselves. This discovery is one of the truly great achievements of infancy.

To investigate infants’ understanding of objects, Piaget (1954) showed them an attractive object and then hid it. If the object exists only when infants perceive it, reasoned Piaget, they will make no effort to look for it when they can’t see it even if they actually saw it being hidden. Looking for a hidden object is clear evidence the child can imagine it and believes it still exists.

Piaget found that young infants do not respond to the object once it is removed. But by about 8 months, they begin to look for the object if it has just been hidden. If a few seconds have passed, they are likely not to search at all. And if an object is hidden in one location—say under pillow A—and then moved to a second location—say pillow B—in full view of the child, even a 12-month-old is likely to search only under pillow A and abandon the search when the object isn’t found. This is known as the A not B error.

According to Piaget, this demonstration, repli- cated many times, illustrates that before the age of 18 months the infant has an incomplete and somewhat fragile understanding of the perma- nence of objects. But other investigators have argued that Piaget’s test may not be entirely con- vincing, and that other approaches might lead to different observations. For example, Baillargeon

Thought Challenge 5.2

Does the fact that infants don’t look for a hidden object prove that they don’t realize that objects have an independent and objective existence?

Infant Cognitive Development Chapter 5

and DeVos (1991) arranged for a short or a long carrot to move behind a windowless yellow screen on a track so that the carrots disappeared from the infant’s view. When the infant had habituated to these two events (that is, looked at them for about the same time), the window- less yellow screen was replaced with a blue one that had a window cut out of the top. The short carrot would still not be visible as it passed behind the screen, but the tall one should be. That it isn’t (due to the experimenters’ surreptitious manipulations) would only be surprising if infants expected it to be (see Figure 5.12). Apparently, even at the age of 3.5 months, many infants stare longer at this “impossible event,” as though surprised by it.

Do these observations mean that Piaget was wrong and that infants have a notion of the per- manence and independent identity of objects long before the age of 18 months? Not really. What they indicate is that under the right circumstances, infants appear to have a short-lived recollection of absent objects, and have begun to understand that objects are solid and stationary.

Though it isn’t entirely clear how infants learn about the solidity and permanence of objects, and about how they move, Rakison and Lupyan (2008) argue that it depends on experiencing objects in the real world, and also on, in their words, “advances in information-processing abilities such as improving short- and long-term memory” (p. 9).

Although it’s probably true that Piaget underestimated the ages at which infants might begin to achieve the object concept, Haith (1998) suggests that researchers are often guilty of the opposite error: They are guilty of too “rich” an interpretation of infant cognition. For

Habituation Events Short carrot event Tall carrot event

Test Events Possible event Impossible event

Figure 5.12: Representation of the Tall and Short Carrot Demonstration

Infants as young as 3.5 months acted surprised when the tall carrot did not appear in the window cutout—as though they understood something of the permanence and expected movements of the carrot. Source: Baillargeon, R., & DeVos, J. (1991). Object permanence in young infants: Further evidence. Child Development, 62, 1227–1246.

Infant Cognitive Development Chapter 5

example, on the basis of a few additional sec- onds of looking at a presumably impossible situ- ation, we want to infer that infants understand things about objects that they probably don’t. Even though 4-month-old infants might seem surprised at the disappearance of expected objects, it will be a long time before they begin to look for these objects even when someone has hidden them before their very eyes.

Intention, Imitation, and Morality in Young Infants

Looking for a hidden object presupposes more than the realization that the object is perma- nent—that it does, in fact, exist under the pil- low or in the hall closet. It assumes as well that the infant is capable of forming the intention of searching for it, and is also capable of acting out that intention.

In its ordinary sense, intentional means purposeful or deliberate. The laws of many societ- ies assume that infants, and even much older children, are incapable of immoral acts simply because they are incapable either of forming prior intentions or of understanding the impli- cations of their behaviors. Discovering when infants are capable of intentional behavior has been an important challenge for developmental psychologists. (See In the Classroom: Bad, Albert. Bad.)

At first glance, this seems a difficult undertaking, given that pre- verbal infants cannot explain their intentions or their goals. Still, infants do many things that show at least the beginnings of inten- tion. For example, they quickly learn to follow someone else’s gaze to see what they’re looking at. This sort of “joint attention,” says Flavell (1999), is an important precursor to intentional com- munication. Also, infants look at, point to, or hold up objects apparently with the intention of having someone else react. Finally, infants’ persistent attempts to imitate provide clear evi- dence of intention.

Imitation, as we saw in Chapter 2, is one of the important ways of learning new things or modifying old behaviors. In some ways, it appears to be a natural way of learning. But is it? Can newborns imitate?

Some researchers think yes; others don’t agree. For example, Meltzoff and Moore (1989) report that at a mere 2 weeks of age, infants are already able to imitate simple actions such as sticking out the tongue or opening the mouth wide. But others suggest that neonates aren’t actually imitating when they stick out their tongue or purse their lips in apparent response to a model. Instead, they

▲ Piaget argues that experiences in the real world are absolutely critical to developing notions about the properties of objects, and about number, space, time, and causality. In a sense, the early journeys of this tiny waif are like scientific expeditions. © iStockPhoto/Thinkstock

▲ There is some controversy over whether infants younger than one month are actually imitating when they stick out their tongues in apparent response to a model – or whether they’re simply emitting a food-related, reflexive response. But that this 3-month-old is imi- tating seems clear. © Ingram Publishing/ Thinkstock

Infant Cognitive Development Chapter 5

might simply be manifesting a generalized, almost reflexive, response related mainly to feed- ing (Kaitz, Meschulach-Sarfaty, Auerbach, & Eidelman, 1988).

It is highly telling that one of the few behaviors that infants younger than 1 month seem to be able to imitate (and often very badly, or not at all), is tongue protrusion (Perra, Parisi, & Caffarelli, 2008)—a behavior closely linked with the rooting, sucking, and swallowing reflexes. After the age of 1 month, this “imitative” behavior declines significantly.

Imitation in Older Infants

It is also significant that the infant is initially capable of imitating only when the model is pres- ent or has just left. Piaget (1951) suggests that deferred imitation—the ability to imitate something or someone no longer present—is not likely to occur before the age of 9 to 12 months. The ability to imitate an action after the fact is strong evidence of the infant’s ability to represent mentally.

The second year of life is a crucial period for the infant’s burgeoning ability to represent men- tally and to imitate. Now infants begin to imitate novel actions. Imitation provides a powerful tool for new learning—and especially for learning language. Nor is the older infant’s imitation limited to imitating and learning only from adults. Toddlers (older infants) imitating other tod- dlers is highly evident in child-care facilities.

Studies of infant imitation provide impressive evidence of the infant’s growing ability to make inferences about other people’s intentions. For example, Meltzoff, Gopnik, and Repacholi (1999) had 18-month-old infants watch while an adult performed an unsuccessful action. The reasoning is that if the infant later imitates what the model actually did, even though it didn’t

I N T H E C L A S S R O O M :

Bad, Albert. Bad.

The Setting: Happy Tots Daycare

The Situation: Eighteen-month-old Albert has just tipped over his juice box. Again.

Mrs. Evert (annoyed): No! Albert. No! No! Bad boy!

Albert: Bad. He slaps himself on the hand. Bad. Bad. And he begins to giggle.

Mrs. Evert: It’s not funny Albert. Bad! Not funny!

Albert: Funny.

Mrs. Evert: Not funny. Not funny at all. Now pick it up and put it in the garbage.

Albert: Funny. Bad. Funny. He slaps himself on the hand again, and starts to laugh. Others laugh, too.

Mrs. Evert. Not funny at all!

To Think About: Singleton (1884), more than a century ago, wrote, “Although it is urged that there are difficulties in the way of giving set lessons on moral subjects at regular intervals to infants, the subject must not be wholly neglected. As the formation of character is continually going on, so should moral teaching be constant” (p. 129). Why do you suppose “lessons on moral subjects” might be wasted on infants? Or do you think not?

Infant Cognitive Development Chapter 5

work, then all that might be involved is a simple, straightforward type of copying. But if the infant tried to imitate the “intended” act, then we might assume that a correct inference has been made about the actor’s intentions. In one study, for example, the experimenter seems to be trying to pull apart a small dumbbell, but fails. In the testing phase, infants typically try to accomplish the inferred intention rather than imitate the model’s actions literally. When they are given oversized plastic dumbbells that they can’t possibly hold in the same way as the model, they make no attempt to mimic the model directly. Instead, they try novel solutions, like placing the dumbbell on a table and pulling on the other end with both hands.

Achievements of Imitation in Infancy

Studies of imitation among infants show a gradual progression from being able to imi- tate simple body movements to imitating actions performed with objects, and, finally, to imitation based on being able to correctly infer the intentions of the model (Rao, Shon, & Meltzoff, 2007).

Infant imitation leads to at least three different kinds of learning. First, infants learn about places by following people around, in much the same way that young kittens and other ani- mals learn about places by following their mothers and siblings. Second, through imitation infants learn certain social behaviors, such as sharing toys. After playing “give and take” games with parents, infants are more likely to want to give toys to others. And third, infants learn new social behaviors by observing them in others. Among the most important of new behaviors that they learn at least partly through imitation are those that have to do with speaking and understanding a language. (See Across Cultures: Saliswa, An African Child.)

Adaptation and Information Processing in Piaget’s Theory

In the beginning, Piaget tells us, the infant’s world is a world of the here and now. Because the infant has no object concept, the world makes sense only when the infant looks at it, hears it, touches it, smells it, or tastes it. Nor do infants have concepts in the sense that we think of them: They have no store of memories or hopes or dreams, no fund of information with which to think. But what neonates have are the sensory systems and the cognitive incli- nations that make them highly effective, information-processing organisms. They continually seek out and respond to stimulation and, in the process, gradually build up a repertoire of behaviors and capabilities.

At first, infants’ behaviors are limited mainly to the simple reflexes with which they are born; but in time these behaviors become more elaborate and more coordinated with one another. The process by which this occurs is adaptation, and the complementary processes that make adaptation possible are assimilation and accommodation (see Chapter 2).

To review briefly, assimilation and accommodation are highly active processes whereby an individual searches out, selects, and responds to information, the end result of which is the actual construction of knowledge. Imagine, for example, an 18-month-old walking on a beach, stooping now and again to pick up pebbles and toss them into the water. In Piaget’s view, there is a schema (plural schemata) involved here—a sort of mental or cogni- tive representation—that corresponds to the child’s knowledge of the suitability of pebbles as objects to be thrown in the water, as well as other schemata that concern the activities involved in bending, retrieving, and throwing. The pebbles are, in a sense, being assimilated to appropriate schemata; they are understood and used in terms of the child’s previous knowledge.

Infant Cognitive Development Chapter 5

Imagine, now, that the child bends to retrieve another pebble but finds, instead, that she has picked up a piece of driftwood. The wood is clearly not a pebble, and perhaps it should not be responded to in the same way. But still, why not? The “throwing things on the big waves” schema is readily available and momentarily preferred, and so the wood too is assimilated to the throwing schema. The child tries to hurl it toward the water, but the new object’s heavi- ness is surprising, the child’s throwing motion inadequate, and the driftwood fails to reach the water. Now, when she picks it up again, she doesn’t hurl it in quite the same way. She holds it in two hands, grasps it tightly with her tiny fingers, and pushes hard with her little legs as she throws. In Piaget’s terms, she has accommodated to the characteristics of this object that make it different from the pebbles she has been throwing.

A C R O S S C U LT U R E S :

Saliswa, An African Child

In ethnographic literature about African peoples,” writes Reynolds (1989), “reference is often made to `the African child’ as if such a composite creature exists” (p. 2). We make the same mistake in psychology. We insist “there is no average child,” but then we keep talking about this nonexistent creature.

Saliswa is not just an average African child. She is one of many Xhosa children who, in 1980, lived in an urban squatter settlement about 20 miles from the center of Cape Town, South Africa. Saliswa, then 2, lived in a shack built of discarded panels of corrugated metal, framed with scraps of lumber, lined with bits of paper and plastic, and floored with cardboard.

Major day-to-day problems in Saliswa’s settle- ment involve getting water; staying warm in win- ter and cool enough in summer; getting access to schools, hospitals, shops, and “crèches” (child- care facilities); and managing to cook on paraffin stoves without burning the house down. “We sleep on our graves,” said one of Saliswa’s neigh- bors (Reynolds, 1989, p. 20).

There are other, perhaps even more serious, prob- lems. For years, the Xhosas lived under the heel of South Africa’s apartheid policies. The shacks they built in the sand were considered illegal; often they were torn down or burnt before their eyes. Parents were imprisoned for being in “white man’s territory.” Children were beaten or sometimes killed; their lives were surrounded by violence. Yet, notes Reynolds (1989), there was remarkably little violence in either their interactions with each other or their games. Educational opportunities were highly limited, future mobility and career opportunities almost nonexistent.

Like Saliswa, more than 300 million of the world’s children live in squatter’s settlements, most of them in the poorest of third-world countries. And although more than 90 percent of all children in the developing world now start school, more than 100 million primary-school-aged children are not in school (UNDP, 2003) (Figure 5.13).

To Think About: What impact do you suppose Saliswa’s context might have on her fantasies? Her dreams? Her play? Her intellectual development?

“

Infant Cognitive Development Chapter 5

To simplify these sometimes difficult concepts, to assimilate is to respond in terms of preexist- ing information. It often involves ignoring some aspects of the situation to make it conform to aspects of the mental system. In contrast, to accommodate is to respond to external char- acteristics and to make changes in the mental system as a result. And one of the governing principles that guides mental activity, says Piaget, is a tendency to find a balance between accommodation and assimilation. This tendency is labeled equilibration.

At one extreme, if an infant always assimilated but never accommodated, there would be no change in schemata (mental structure), no change in behavior, and, by definition, no learning. Everything would be assimilated to the sucking schema, the grasping schema, the looking schema (that is, everything would be sucked or grasped or simply looked at). Such a state of disequilibrium would result in little adaptation and little cognitive growth.

At the other extreme, if everything were accommodated to and not assimilated, schemata— and behavior—would be in a constant state of flux: First the nipple would be sucked, then it would be chewed, now pinched, then swatted. Again, such an extreme state of disequilibrium would result in little adaptation.

FIGURE 05.13

United States

Canada

Australia

Japan

Mexico

China

Algeria

Bangladesh

Angola

India

Guatemala

Afghanistan

Benin

Bhutan

Burkina Faso

Average years of schooling for selected countries

0 2 4 6 8 10 12 14

Figure 5.13: Average Years of Schooling by Country

Average years of schooling in a few of the 199 countries for which data is available. Source: Human Development Reports (2011). United Nations Development Programme, New York. Retrieved August 29, 2011, from http://hdr.undp.org/en/statistics/

data/2011/

http://hdr.undp.org/en/statistics/data/2011/

Infant Cognitive Development Chapter 5

Equilibration, says Piaget, is one of the four forces that shape development (Piaget, 1961). Another is maturation, a sort of biologically determined unfolding of potential. Maturation— or biology—does not determine cognitive growth but is related to its unfolding. A third factor is active experience, a child’s interaction with the world. A fourth factor is social interaction, which helps the child develop ideas about things, about people, and about the self. These four factors—active experience, maturation, equilibration, and social interaction—are the cor- nerstones of Piaget’s basic theory. (Table 5.3)

Table 5.3 Piaget’s Four Factors that Shape Development

Factor Description

Equilibration The tendency to balance assimilation (responding in terms of previous learning) and accommodation (changing behavior in response to the environment)

Maturation Genetically influenced changes that underlie the sequential development of new adaptations

Active Experience Interaction with real objects and events allows individual to discover things and to invent (construct) mental representations of the world

Social Interaction Interaction with people leads to the elaboration of ideas about things, people, and self

Sensorimotor Development

Piaget believed that children’s understanding of the world throughout most of infancy is deter- mined by the activities they can perform on it and by their perceptions of it—hence his label sensorimotor development for this first stage, which spans infancy. (Figure 2.9, Chapter 2, summarizes all Piaget’s stages.)

Sensorimotor development, says Piaget (1961), can be described in terms of six substages. During the first, which lasts about a month, infants spend much of their waking time exercis- ing the abilities with which they are born (sucking, looking, and crying, for example). By the end of the first month, infants are quite proficient at these activities, but they have trouble putting different actions together (coordinating their behavior) to obtain a goal. When shown a shiny new bauble, an infant stares at it intently but cannot reach toward it.

The second sensorimotor stage, lasting from one to four months, is marked by highly repeti- tive behaviors (thumb sucking, for example) called primary circular reactions. These are behaviors that are initially reflexive and that serve as stimuli for their own repetition. For example, if an infant accidentally gets a hand or a finger into the mouth, this triggers the sucking response, which results in the sensation of the hand in the mouth. That sensation leads to a repetition of the response, which leads to a repetition of the sensation, which leads to a repetition of the response. This circle of action is called primary because it involves the infant’s own body.

Between ages 4 and 8 months, secondary circular reactions appear. Like primary circular reactions, they are circular because the responses stimulate their own repetition; but because they deal with objects in the environment rather than only with the infant’s body, they are called secondary. Six-month-old infants engage in many secondary circular reactions. They accidentally do something that is interesting or amusing and then repeat it again and again. By kicking, Piaget’s infant son caused a row of dolls dangling above his bassinet to dance. The boy stopped and watched the dolls. Eventually, he repeated the kicking, perhaps not intend- ing to make the dolls move, but probably because they had stopped moving and no longer

Early Language Development Chapter 5

attracted his attention. As he kicked, the dolls moved again, and again he paused to look at them. In a very short time he was repeating the behavior over and over—a circular reaction. This behavior, which Piaget described as “behavior designed to make interesting sights and sounds last,” is especially important because it signals the beginning of intention.

The development of intention becomes even more apparent when, in the fourth substage (8 to 12 months), infants acquire the ability to coordinate previously unrelated behaviors to achieve some desired goal. They can now look at an object, reach for it, grasp it, and bring it to the mouth with the intention of sucking it.

In the fifth substage (12 to 18 months), infants begin to modify their repetitive behaviors deliberately to see what the effects will be. These tertiary circular reactions are evident in exploratory behaviors, in which an infant takes a piece of spaghetti, presses it to the floor, breaks it, picks up the largest piece, breaks it again, and repeats the process a number of times. The most important feature of tertiary circular reactions is that they are repetitive behaviors deliberately undertaken to see what their effects will be; that is, they are explorations.

Toward the end of the sensorimotor period, infants are well on their way to making a tran- sition from what has been an action-based (hence sensorimotor) intelligence to a progres- sively more cognitive (symbolic or representational) intelligence. Infants can now represent objects and events mentally. They can even occasionally combine these representations to arrive at mental solutions for problems, and they are now able to anticipate the con- sequences of many of their activities before actually executing them. In Piaget’s terms, it is as though the child can now begin to internalize (represent mentally) actions and their consequences without having to carry them out. We do this all the time. We call it think- ing or information processing. One of the advantages of Piaget’s use of the expression internalizing actions is that it draws attention to how closely the infant’s (and the child’s) thinking is linked to physical action, emphasizing how important early experiences are in the development of thought.

The process of internalizing actions is well illustrated by Piaget’s account of his daughter’s behavior when she was given a partly open matchbox containing a small thimble. Because the opening was too small for her to withdraw the thimble, she had to open the box first. A younger infant would simply grope at the box, attempting clumsily to remove the thimble. But Piaget’s daughter, then 22 months, appeared to be considering the problem. She opened and closed her mouth repeatedly as if displaying internal thought processes—as if, in a sense, imagining (and unconsciously illustrating with her mouth) the opening and closing of the box. Finally, she placed her finger directly into the box’s partial opening, opened it, and removed the thimble (See Concept Summary: Piaget’s Six Substages of Sensorimotor Development.)

5.6 Early Language Development Piaget’s 22-month-old daughter could not only solve the opening-the-box problem: If she so wished, she could tell everybody about her triumph! And she could now do so not only by jumping up and down and shrieking, but also by using actual words.

Despite its tremendous power, language is not always essential for communication (the transmission of messages)—as an infant jumping up and down and shrieking, or a dog growl- ing, clearly demonstrate. Language is the use of arbitrary sounds (or, in some cases, gestures, as in American Sign Language (ASL)), in purposeful ways to convey different meanings.

Early Language Development Chapter 5

The Prespeech Stage of Language Development

Infants’ first communication system is not a language so much as a system of gestures and sounds. To master a language, infants needs to learn not only how to produce sounds and gestures, but also how to take turns, and how to discriminate sounds.

Turn Taking: The Beginnings of Verbal Communication

The ability to use and to understand words grows out of the interactions that take place between infants and their caregivers, siblings, and other people. One of the first things the infant learns through this support system is how to take turns—an achievement that is basic to adult conversation.

Amazingly, infants seem to have a relatively sophisticated awareness of turn-taking signals at very young ages. In one investigation, Elias and Broerse (1996) looked at interactions between 48 mothers and their 3- to 24-month-old infants. They found a remarkable tendency for mother-infant pairs to interact in alternating fashion.

Concept Summary: Piaget’s Six Substages of Sensorimotor Development

Substage and Approximate Age in Months

Principal Characteristics

Infant States

1. Exercises reflexes (0–1)

Practices simple, unlearned behaviors (schemes) such as sucking and looking

2. Primary circular reactions (1–4)

Repeats pleasant activities, such as thumb sucking, that center on the body

3. Secondary circular reactions (4–8)

Repeats activities that lead to inter- esting sights or sounds (beginning of intentionality)

4. Purposeful coordination (8–12)

Coordinates activities (such as looking and reaching); recognizes familiar people and objects

5. Tertiary circular reactions (12–18)

Explores by repeating actions with deliberate variations

6. Mental representation (18–24)

Internalizes actions (thinks); antici- pates consequences; transition to a more cognitive intelligence; language becomes increasingly important

▲ A primary circular reac- tion that, for most of us, is more difficult than sucking our thumbs. © Laurence Monneret/Getty Images

▲ A tertiary circular reac- tion: This tyke explores people’s reactions by repeating his grimaces with variations. © Andre Gallant/Getty Images

Early Language Development Chapter 5

Using Gestures

Even before they have begun to use words, infants have typically developed a repertoire of gestures that are clearly meaningful for both infants and caregivers. Many of these are associ- ated with gazing, which is used to direct people’s attention and to indicate desired objects. Also, very much like adults, infants often follow another person’s gaze.

During the first two years, infants develop a large number of different gestures that they can use in place of, or in combination with, words. Interestingly, bilingual children tend to use more gestures when speaking their dominant rather than their second language (Laurent, Nicoladis, & Marentette, 2010). Also interesting is the finding that older adults who are begin- ning to lose some of their language skills often resort to an increasing use of gestures (Goldin- Meadow & Iverson, 2010).

Among gestures commonly used by infants, pointing is one of the last to develop (at around ages 12 to 14 months) (Masur, 1993). Other gestures, such as offering objects and reaching for things, are relatively common by the age of 9 months. By the age of 15 months, infants can direct their gazing and their pointing in different directions at the same time. This is evident, for example, when a 16-month-old points to the plate he has just thrown on the floor and looks at his mother at the same time. Being able to refer to two objects at once is a remarkable new achievement.

The use of gestures by caregivers plays an important role in the infant’s early learning of lan- guage. For example, de Villiers Rader and Zukow-Goldring (2010) found that when parents used dynamic gestures synchronized with both the sight of an object and the word associated with it, infants paid more attention to the object and learned the word better.

Discriminating Sounds

Communicating through language depends on being able to discriminate sounds as well as produce them. Auditory speech, Werker and Tees (1999) point out, is far more complex than written language. What you are reading at this moment consists of words that are separated by spaces and that are organized into sentence-sized chunks whose meaning is signaled with punctuation, capitalization, boldfacing, and italicizing. Furthermore, you can reread any part of it at your whim. Not so with speech. Examination of acoustic waves shows no regular breaks between words, and no division between sentences or paragraphs. Yet infants are soon able to discriminate individual sounds. And before a year has passed, they have even begun to assign them meanings.

Sound Production

Discriminating among sounds is one aspect of early language learning; producing intended sounds is the other. It starts with the crying, cooing, and eventual babbling of the infant. Eventually it progresses to a word, and then a sentence, a paragraph, a chapter, a book . . .

Infants’ first sounds are haphazard and varied, but they soon gain control over their sound- producing apparatus. Also, they discover that

Thought Challenge 5.3

Baby talk, called parentese, is found not only among caregivers talking to infants and young children, but also among male and female adults and among caregivers talking to elderly people—in which case it is called secondary baby talk. What do you suppose some reasons might be for the use of secondary baby talk?

Early Language Development Chapter 5

producing sounds is “fun,” and contented infants may spend hours in solitary babbling without any prompting. As a result, by the age of 10 months, most children babble clearly, systemati- cally, and repetitively. Children who have mild hearing problems reach this stage later; if their hearing problems are serious enough, they do not progress through the normal stages of bab- bling and language learning (Bass-Ringdahl, 2010).

The First Word

At around 1, but sometimes much earlier or much later, the first word appears—not surpris- ingly, often “mama” or “papa”—although it is seldom easy to determine when infants say their first word. Often, the first consistent sound made repeatedly by an infant is not a word but has clear meaning. These sounds are referred to as protowords.

Holophrases also appear early in the speech stage of language learning. Unlike protowords, these are real words rather than just sounds, and their meaning is often complex and elabo- rate. The holophrase “up” allows an 18-month-old to convey the meaning “If you don’t pick me up I will do something very annoying,” without having to use more than one word.

The appearance of the first word is rapidly followed by new words that the child practices incessantly. Most of an English-speaking child’s first words are nouns—simple names for simple things, usually objects or people that are part of the here and now: “dog,” “mama,” “banket” (blanket), or “yefant” (elephant). Verbs, adjectives, adverbs, and prepositions are acquired primarily in the order listed here, with the greatest difficulty usually being the use of pronouns, especially the pronoun “I” (Boyd, 1976).

Two-Word Sentences

By the age of 18 months, most infants have begun to make two-word sentences—often grammatically incorrect but always meaningful. There is also normally a tremendous spurt in vocabulary, which appears to be common to all cultures. Whereas learning the first hun- dred words might take several months, learning the next hundred might only take a few weeks (Yu, 2008). This process is called fast mapping. (See In the Classroom, I Should Like to . . .)

Multiple-Word Sentences

Multiple-word sentences typically appear shortly after the age of 2. Early preschool speech is often telegraphic speech—so-called because it eliminates many parts of speech while still managing to convey meanings. And although it is often grammatically incorrect, it includes complex grammatical variations to express different meanings. By the late preschool years, it has become adultlike (Table 5.4).

Three Explanations for Language Learning

We know that learning a language requires certain biological characteristics—vocal appara- tus, hearing, the brain. We know too that it is highly dependent on experiences with others who have already acquired a language. The story of Genie, described in Chapter 3, makes that clear. Genie was rescued at age 13, at which time she had a vocabulary of about 20 words—mostly short, negative phrases such as “stop it,” and “no more.” In addition, she had developed a limited repertoire of gestures consisting mostly of spitting and clawing. But most

Early Language Development Chapter 5

I N T H E C L A S S R O O M :

I Should Like to Inform You That Maria Theresa, We Call Her Mati, Splashed Me with Water

The Situation: Two-year-old Rory’s mother has just picked him up from daycare.

Mother: How was your day, Rory?

Rory: Yeah. Day agua.

Mother: Deyawa! What’s deyawa?

Rory: Splash agua Mati. Splash, splash.

Mother: Sounds like you’re having a bath. Did you have a yummy lunch, Rory?

Rory: Splash agua. Mati splash. Poooof. Splash. (Giggles.)

Mother: Did you solve any big problems today, Rory? Global warming? Global warring? Hunh?

Rory, pointing excitedly as they drive along the lake shore: Agua, agua, agua.

Mother: Ahhh. Agua! Water! You learned another Spanish word.

To Think About: Despite the repetitive and telegraphic nature of his little sentences, Rory is in the fast mapping stage of language development. There is a strong likelihood that he may have learned more than just one new Spanish or English word at daycare that day. Preschoolers exposed simulta- neously to two languages can become fluently bilingual seemingly effortlessly, especially if both lan- guages are well-supported in the community. Do you suppose this might present some advantages over trying to learn a second language later in life?

Table 5.4 General Sequence of Infant Language Development

Stage Main Accomplishments Sample Utterances

Prespeech (before age 1)

Turn taking

Using gestures such as pointing

Discriminating and producing sounds

“Waaaaaa. . .”

“Gooogoooogoooogaaahgaah”

First Words (around age 1)

Protowords (non-words with consistent meaning)

Holophrases (single words with sentence-like meanings)

“bruk” meaning all toys that make noise

“Mama” Meaning “Would you please come here mother and bring the milk with you. . .”

Two-word sentences (around age 18 months)

Vocabulary spurt

Fast mapping (one-exposure learning)

“Doggie gone”

“Up me”

Multiple-word sentences (by age 2 to 21/2)

Longer sentences; more gram- matical variation; increasingly correct use of word classes

“Read again book.”

“I no can play”

“I runned fast”

Early Language Development Chapter 5

of the time, she was silent—evidence, says Rymer (1994), that she had not been exposed to language during critical periods of her life.

In spite of being rescued at age 13, and even though dedicated therapists worked with her over a long period, Genie’s language development reached only a very primitive level, as shown in this excerpt of a conversation she had with one of her foster mothers, Marilyn Rigler:

Marilyn Rigler: Do you remember what it was like when you lived at home? What were you sitting on when you ate the cereal?

Genie: In the pot.

Marilyn Rigler: In the potty chair.

Genie: In the potty chair.

Marilyn Rigler: Where did you stay when you lived at home? Where did you live? Where did you sleep?

Genie: Potty chair.

Marilyn Rigler: You slept in the potty chair?

Genie: Mmm-hmm. Potty chair. (Secrets of the wild child, 1997)

Language, some theorists insist, is a sort of special gift given only to humans and not other animals; its acquisition can only be explained by reference to things extraordinary and mysteri- ous. Deacon (1997) labels such explanations hopeful monsters; other theorists refer to them as a form of nativism (MacWhinney, 1998).

The best known of the hopeful monster or nativistic theories of language development is that of the linguist, Noam Chomsky (1972). Chomsky argues that because children learn language, and especially grammar, so rapidly, and because they make so few of the errors that one might expect them to make if they had to learn each rule and each exception individually, they must be born with a powerful biological predisposition to learn language. This predisposition, Chomsky speculates, takes the form of neurological pre-wiring in the brain, corresponding to language and grammar, which he labels the language acquisition device (LAD).

Another explanation views language acquisition as the end result of a learning process highly dependent on interaction with other speakers. This explanation sees language as something that emerges gradually and is labeled emergentism (MacWhinney, 1998). Emergent expla- nations are often based on the principles of reinforcement in operant conditioning (described in Chapter 2). They might argue, for example, that while babbling, the infant emits wordlike sounds that tend to be reinforced by adults.

A third explanation is the interactionist theory of language learning. It is both a biologi- cal and social explanation—biological in that it holds that children are born with a powerful, innate predisposition to learn language, and social in that the learning of language involves the fundamentally social act of sharing symbols and meanings with others. Vygotsky is closely associated with the interactionist view.

The most popular current explanations are basically interactionist. Though they recognize the child’s biological predispositions, they tend to focus on the mental and social processes involved in language learning.

Section Summaries Chapter 5

5.7 From Sensation to Representation The word infant derives from the Latin infans, meaning “without speech.” And, in fact, throughout much of the period we call infancy, a child is without speech. As noted earlier, the world of the newborn is a world of the here and now, a world that cannot be represented symbolically but can only be acted on and felt—in short, a sensorimotor world.

Although the term sensorimotor describes well the predominant relationship between infant and world, it doesn’t describe the most important cognitive achievements of the first two years of life. By the time a child is 2, the world no longer exists only in the immediate, sensible present. Objects have long since achieved permanence and an identity that no longer depend solely on the child’s activities; there is a dawning understanding of cause-and-effect relationships; lan- guage is rapidly exercising a profound effect on cognitive development. These achievements, together with children’s recognition of their own identities (their selves) represent a dramatic transition from a quasi-animalistic existence to the world of thought and emotions as we know it. Although it is a dramatic transition, at least in its import, it is neither sudden nor startling. Those who follow the journeys of individual children closely (and daily) never see the transition from sensorimotor intelligence to preoperational thought. It happens suddenly and irrevocably on the second birthday only in textbooks. Real life is less well organized.

Section Summaries 5.1 Nutrition, Growth, and Survival in Infancy Breast milk is among the most easily digested foods for infants and is useful in guarding against the possibility of illness and dis- ease. Severe malnutrition may be manifested in stunting (retarded height) or wasting (severely below-average weight). Sudden infant death syndrome (SIDS) (more common among males) now accounts for the unexpected and largely unexplainable death of fewer than 1 in every 1,000 infants, a significant reduction attributed mainly to medical advice regarding placing infants supine or on their sides to sleep.

5.2 Brain Growth and Motor Development Optimal brain development in early infancy is influenced by nutrition (especially protein intake) and environmental stimulation. There is a spurt in brain growth at the end of the fetal period, continuing during infancy. The cerebrum is involved in higher mental functions, and develops very rapidly during infancy (through brain proliferation, consisting largely of the mushrooming of neural connections and myelin sheaths). Degree of brain arousal is evident in infant states (conditions of sleep, alertness, or activity). The neonate’s behaviors consist mainly of survival reflexes such as sucking, breathing, rooting, sneezing, and swallowing and generalized reflexes such as the moro and Babinsky. Motor development tends to be cephalocaudal (from head to foot) and proximodistal (from near to far). Cerebral palsy is a significant developmental motor disability related to brain injury; developmental coordination disorders are evident in difficulties in learning motor tasks.

5.3 Sensation and Perception in Infancy Sensation is primarily a physiological process; per- ception is our interpretation of sensation; conceptualization is a more cognitive process. Depth perception, response to patterns, and the ability to detect movements are well developed in newborns. Hearing is present before birth. Infants appear to recognize and prefer their mother’s voice at ages as young as 3 days. Almost from birth, infants prefer pleasant odors and sweet tastes. They appear to be sensitive to touch (and to pain) within a few hours of birth.

5.4 Memory in Infants Habituation studies indicate that infants have fleeting and frag- ile memories at least during the first half year—although reminders sometimes help them

Possible Responses to Thought Challenges Chapter 5

remember things longer. By the age of 8 months, neonates’ memories have become more abstract, although they, like us, appear to be subject to the phenomenon of infantile amnesia— an inability to remember personal experiences of our infancies and early childhoods.

5.5 Infant Cognitive Development Piaget describes the infant’s world as one of the here and now with no object concept prior to 8 months. Some newer research indicates that they understand some of the physical properties of objects before then. Intention is evident in the very young infant’s gazes, gestures, and imitative behaviors. Cognitive growth results from a balance (equilibration) of assimilation and accommodation, influenced by maturation, active experience, and social interaction. Piaget’s six substages of the sensorimotor period are exercising reflexes (0–1 month); primary circular reactions (repetitive self-centered behaviors; 1–4 months); secondary circular reactions (repetitive environment-centered behaviors; 4–8 months); purposeful coordinations (the coordination of activities in goal-oriented behaviors); tertiary circular reactions (exploring by modifying behaviors; 12–18 months); and mental rep- resentation (transition to a more symbolic intelligence; 18–24 months).

5.6 Early Language Development Language, the use of arbitrary sounds to convey mean- ings, is not necessary for communication. In the prespeech stage, infants learn sound and gesture production, turn taking, and sound discrimination. Gazing is among the earliest of their communicative gestures. Protowords, sounds that aren’t words but have consistent meanings, often appear before the first word, which is often sentence-like in nature (a holo- phrase), followed by two-word sentences and a vocabulary spurt (fast-mapping by age of 18 months). First sentences are telegraphic, condensing considerable information into two words. Explanations for language learning include hopeful monster theories (wired-in predis- position to learn language), emergentism (based on learning principles), and interactionism (biological and social factors both involved).

Focus Questions: Applications 1. How important is nutrition for a newborn? As a class project, organize a breast versus

bottle debate.

2. What are some important physical and intellectual characteristics of neo- nates? Evolution, we are told, is a poor engineer. Try your hand at designing the human organism. Start with something as ignorant as a newborn. What kinds of capabilities and propensities would you design into a newborn? How do these compare with what is actu- ally there?

3. What can a newborn see? Hear? Smell? Taste? Feel? An infant’s world is a blooming, buzzing mass of confusion, thought William James. Explain why this statement is true or false.

4. Can newborns think? What sorts of thoughts, if any, do you suppose a newborn would have? What changes would you expect in the first year?

5. How can an infant manage to learn something as complicated as a language? Why are theories based on imitation not entirely adequate explanations for language learning?

Possible Responses to Thought Challenges Possible response to Thought Challenge 5.1: Learning what the visual world means, and the development of the physiology of the visual system, are highly dependent on early experience.

Study Terms Chapter 5

Possible response to Thought Challenge 5.2: Not necessarily. Perhaps even very young infants really do understand the permanence of objects, but aren’t able to form the intention to search for an object. Or perhaps they’re not especially motivated to do so. Or maybe they simply don’t have the type of control over their physical movements that is required for an actual search. What kinds of tasks could you present an infant to determine which of these explanations is most probable?

Possible response to Thought Challenge 5.3: (1) The use of baby talk with elderly people may be due partly to their real—or presumed—problems related to hearing or comprehending. In a sense, they may be perceived as having become more childlike in these respects. Interestingly, a study of secondary baby talk in a nursing home in Germany reveals that it isn’t necessarily bad for residents. Some elderly people report extremely positive reactions to baby talk (Sachweh, 1998).

(2) Baby talk among adults may be an indication of intimacy and attachment, and a means of achieving closeness, say Bombar and Littig (1996). After all, it mimics—and probably brings to mind—moments of great affection between caregivers and infants.

Study Terms A not B error accommodation adaptation altricial American Sign Language (ASL) arousal assimilation autobiographical memories axon babbling Babinski reflex brain proliferation brain stem breathing reflex cataracts cell body cephalocaudal cerebellum cerebral cortex cerebral palsy cerebrum cognitive communication conceptualization deferred imitation dendrites developmental coordination

disorder

emergentism equilibration fast mapping fine motor development functional magnetic

resonance imaging (fMRI) gestures gross motor development habituation holophrases hopeful monsters infantile amnesia infant state intention interactionist theory internalizing actions kwashiorkor lactating language language acquisition device

(LAD) malnutrition maturation memory moro reflex myelin sheath nativism nerves

neurons object concept orienting response palmar reflex parentese perception precocial primary circular reactions prone protowords proximodistal reflex rooting reflex schema secondary circular reactions sensation significant developmental

motor disability stunting sucking reflex sudden infant death

syndrome (SIDS) supine synapse telegraphic speech tertiary circular reactions visual acuity wasting