Chapter 5: Cognitive Development in Infancy and Toddlerhood

sensorimotor stage (birth to 2 years)

infants and toddlers "think" with their eyes, ears, hands, and other sensorimotor equipment. By the end of toddlerhood, children can solve practical, everyday problems and represent their experiences in speech, gesture, and play.

This stage is divided into six substages.

Piaget believed that at birth the circular reaction, which involves stumbling onto a new experience caused by the baby's own motor activity and then repeating the event again and again, provides a special means for babies to adapt their first schemes. The circular reaction initially centers on the infant's own body but later turns outward, toward manipulation of objects. In the second year, it is aimed at producing novel outcomes

sensorimotor substages

Substage 1: Piaget saw newborn reflexes, such as sucking and grasping, as the building blocks of sensorimotor intelligence.

Substage 2 (starting around 1 month): Babies begin to gain voluntary control over their actions through the primary circular reaction—repeating chance behaviors largely motivated by basic needs. Substage 3 (4 to 8 months): Babies' motor achievements, such as sitting up and reaching for and manipulating objects, strengthen the secondary circular reaction, through which babies try to repeat interesting events in the surrounding environment that are caused by their own actions.

Substage 4 (8 to 12 months): Infants engage in intentional, or goal-directed, behavior. (1) In this substage, babies coordinate schemes deliberately to solve simple problems. (2) Babies now begin to master object permanence, the understanding that objects continue to exist when out of sight. (3) Infants in Substage 4, who can better anticipate events, sometimes use their capacity for intentional behavior to try to change those events.

Substage 5 (12 to 18 months): The tertiary circular reaction emerges as toddlers begin to repeat behaviors with variation and develop the capacities to experiment and to imitate many more behaviors.

Substage 6 (18 to 24 months): This substage brings the ability to create mental representations—internal depictions of information that the mind can manipulate— including both images and concepts. Piaget noted that 18- to 24-month-olds arrive at solutions suddenly rather than through trial and error— evidence that they can mentally represent their experiences.

Representation allows older toddlers to solve object permanence problems involving invisible displacement— finding a toy moved while out of sight—because it permits deferred imitation, the ability to remember and copy the behavior of models who are not present.

Representation also makes possible make-believe play.

Piaget's Ideas About Cognitive Change

Piaget believed that organized ways of making sense of experience—called schemes—change with age through adaptation and organization.

Adaptation

Adaptation involves building schemes through direct interaction with the environment, through assimilation and accommodation.

Assimilation involves using our current schemes to interpret the external world.

Accommodation involves creating new schemes or adjusting old ones when we notice that our current ways of thinking do not capture the environment completely.

Organization: Schemes also change through organization, which takes place internally as children rearrange schemes and link them with other schemes to create a strongly interconnected cognitive system

Follow-Up Research on Infant Cognitive Development

Many studies show that infants display a wide array of understandings earlier than Piaget believed—for example, that even newborns try to explore and control the external world

violation-of-expectation method

Researchers capitalize on habituation to investigate what infants know about hidden objects and other aspects of physical reality. Other researchers debate about the meaning of conclusions based on this approach.

Researchers habituate babies to a physical event (expose them to the event until their looking declines) to familiarize them with a situation in which their knowledge will be tested.

Researchers also show babies an expected event, which follows physical laws, or an unexpected event, which does not.

Heightened attention to the unexpected event suggests the infant is "surprised" by the deviation from physical reality and, therefore, is aware of that aspect of the physical world.

object permanence

In studies using the violation-of-expectation method, Renée Baillargeon and her collaborators claimed to have found evidence for object permanence in the first few months of life. However, several researchers using similar procedures failed to confirm these findings.

Investigators recording the ERP brain-wave activity of 6-month-olds found brain-wave patterns that were the same as those of adults told to sustain a mental image of an object.

Even if young infants have some notion of object permanence, Piaget's finding that babies capable of reaching do not try to search for hidden objects before 8 months of age suggests that such searching is a true cognitive advance.

Mastery of object permanence is a gradual achievement. Success at object search tasks coincides with rapid development of the frontal lobes of the cerebral cortex and depends on a variety of experiences perceiving, acting on, and remembering objects.

mental representation

Studies of deferred imitation and problem solving reveal that representational thought occurs in babies significantly earlier than Piaget believed.

Deferred and Inferred Imitation

(1) Laboratory research suggests that deferred imitation, a form of representation, is present at 6 weeks of age.

(2) Between 12 and 18 months, toddlers use deferred imitation skillfully to enrich their range of sensorimotor schemes, and they retain modeled behaviors for at least several months.

(3) The ability to recall modeled behaviors in the order they occurred—evident as early as 6 months—also strengthens over the second year.

(4) Toddlers even imitate rationally, by inferring others' intentions.

(5) Between 14 and 18 months, toddlers become increasingly adept at imitating actions an adult tries to produce, even if these are not fully realized.

problem solving

Infants develop intentional means-end action sequences around 7 to 8 months, as Piaget indicated, but their representational skills soon permit more effective problem solving than Piaget's theory suggests.

By 10 to 12 months, infants can solve problems by analogy, applying a solution strategy from one problem to other relevant problems.

symbolic understanding

The realization that words can be used to cue mental images of things not physically present—the symbolic capacity called displaced reference— emerges around the first birthday.

This capacity greatly expands toddlers' capacity to learn about the world through communicating with others.

Awareness of the symbolic function of pictures also emerges in the second year

TV and learning

Although parents assume that babies learn from TV and videos, research indicates that they cannot take full advantage of them. One- to 3-year-old heavy viewers of television tend to have attention, memory, and reading difficulties in the early school years.

Evaluation of the Sensorimotor Stage

Although some cognitive attainments of infants fit within Piaget's time frame, others emerge earlier than Piaget expected and do not develop together in the neat, stepwise fashion that he assumed.

Consistent with Piaget's ideas, sensorimotor action does help infants construct some forms of knowledge, yet they also comprehend a great deal before they are capable of the motor behaviors Piaget assumed led to those understandings. Alternative Explanations

Most researchers now believe that infants have some built-in cognitive equipment for making sense of experience, but disagreement exists over the extent of this initial understanding.

Some researchers believe that babies' cognitive starting point is limited to a set of biases for attending to certain information, as well as some general-purpose procedures for analyzing complex perceptual information.

Others support the core knowledge perspective: Babies are born with a set of innate knowledge systems, or core domains of thought, that support early, rapid development.

(1) In the first few months of life, infants already have some physical knowledge— awareness of basic object properties, such as object permanence, object solidity, and gravity.

(2) An inherited foundation of linguistic knowledge enables swift language acquisition in early childhood. (3) Infants' early orientation toward people initiates swift development of psychological knowledge.

(4) Research even suggests that infants have basic numerical knowledge.

The core knowledge perspective acknowledges that experience is essential for children to extend their initial knowledge.

Piaget's legacy

Follow-up research on Piaget's sensorimotor stage yields broad agreement that many cognitive changes of infancy are gradual and continuous and that various aspects of infant cognition change unevenly. Piaget's work has been of great practical and theoretical value, inspiring a wealth of research on infant cognition.

information processing model

A cognitive understanding of memory, emphasizing how information is changed when it is encoded, stored, and retrieved.

In contrast to Piaget's unified theory of cognitive development, information processing focuses on many aspects of thinking, including attention, memory, categorization skills, and problem solving. It often relies on flowcharts to describe the human cognitive system.

Information-processing researchers assume that we hold information in three parts of the mental system: the sensory register, the short-term memory store, and the long-term memory store

Research indicates that aspects of the cognitive system improve during childhood and adolescence: (1) the basic capacity of its stores, especially working memory; (2) the speed with which information is worked on; and (3) the functioning of the central executive.

sensory register

where sights and sounds are represented directly and stored briefly.

short-term memory store

we retain attended-to information briefly so we can actively "work" on it to reach our goals.

(1) An indicator of the capacity of the short-term store is working memory, the number of items that can be briefly held in mind while also engaging in some effort to monitor or manipulate those items.

(2) Though the sensory register can take in a wide panorama of information, short-term and working memory are far more restricted.

(3) To manage the cognitive system's activities, the central executive directs the flow of information and also engages in more sophisticated activities that enable complex, flexible thinking.

(4) When the central executive effectively joins with working memory to process information, automatic processes—cognitive activities that are so well-learned that they require no space in working memory— can develop.

long-term memory

The more we effectively process information in working memory, the more likely it will transfer to the third, and largest, storage area—long-term memory, our permanent knowledge base.

executive function

the diverse cognitive operations and strategies that enable us to achieve our goals in cognitively challenging situations.

attention

Infants gradually become more efficient at managing their attention, taking in information more quickly.

In the second year, attraction to novelty declines and sustained attention improves

memory

Operant conditioning and habituation provide windows into early memory, showing that retention of visual events increases dramatically over infancy and toddlerhood.

recognition

noticing when a stimulus is identical or similar to one previously experienced—is the simplest form of memory

recall

involves remembering something not present; by the second half of the first year, babies are capable of it.

infantile amnesia

Refers to the fact that most people cannot retrieve events that happened before age 3.

The decline of infantile amnesia is probably a product of neurobiological change and social experience. Brain development and adult-child interaction may foster the skills preschoolers need to begin to construct long-lasting autobiographical memory—a narrative of their lives.

categorization

Even young infants can categorize, grouping similar objects and events into a single representation to help them learn and remember.

Babies' earliest categories are based on similar overall appearance or prominent object part; by the second half of the first year, more categories appear to be based on subtle sets of features.

As they gain experience in comparing to-be-categorized items in varied ways and as their store of verbal labels expands, toddlers start to categorize flexibly.

By the end of the second year, toddlers' grasp of the animate-inanimate distinction expands.

Exploration of objects and expanding knowledge of the world contribute to the shift from categorizing based on prominent perceptual features to categorizing on a conceptual basis.

Evaluation of Information-Processing Findings

The information-processing perspective underscores the continuity of human thinking from infancy into adulthood, challenging Piaget's view of early cognitive development.

The central strength of this approach is in analyzing cognition into its components, but information processing has had difficulty deriving a broad, comprehensive theory from these components.

A recent trend has been the application of a dynamic systems view to early cognition, which involves analyzing each cognitive attainment to see how it results from a complex system of prior accomplishments and the child's current goals.

Vygotsky's Sociocultural Theory

Vygotsky's sociocultural theory holds that complex mental activities are based in social interaction: Through joint activities with more mature members of their society, children master activities and think in ways that are meaningful in their culture.

Vygotsky's concept of the zone of proximal development refers to a range of tasks too difficult for the child to do alone but possible with the help of more skilled partners.

Although Vygotsky's ideas have been applied mostly to older children, recently they have been extended to infancy and toddlerhood.

Vygotsky shows how cultural variations in social experiences affect mental strategies.

mental tests

measure cognitive products that reflect mental development and predict future performance

Infant and Toddler Intelligence Tests

Because babies cannot answer questions or follow directions, infant intelligence tests simply present stimuli and observe the babies' responses.

Most infant tests emphasize perceptual and motor responses; some new tests focus on early language, cognition, and social behavior

Bayley Scales of Infant and Toddler Development

are used with children from 1 month to 3½ years of age; the Bayley-III includes three main subtests: the Cognitive Scale, the Language Scale, and the Motor Scale.

Two additional Bayley-III scales depend on parental report: the Social-Emotional Scale and the Adaptive Behavior Scale.

Computing Intelligence Test Scores

Intelligence tests are scored by computing an intelligence quotient (IQ), which compares the individual's performance to performances of same-age individuals.

Test designers use standardization—giving the test to a large, representative sample and using the results as the standard for interpreting scores.

Within the standardization sample, results at each age level form a normal distribution, in which most scores fall near the mean, or average, with progressively fewer toward the extremes.

Predicting Later Performance from Infant Tests

Infant tests are poor predictors of later intelligence. Infants and toddlers easily become distracted, fatigued, or bored during testing, so their scores often do not reflect their true abilities. However, the Bayley-III Cognitive and Language Scales are good predictors of preschool mental test performance. Because most infant test scores do not tap the same dimensions of intelligence assessed in older children, they are labeled developmental quotients (DQs), rather than IQs.

Because infant test scores are somewhat better at making long-term predictions for extremely low-scoring babies, they are largely used to help identify babies who are likely to have developmental problems.

home environment and mental development

The Home Observation for Measurement of the Environment (HOME) is a checklist for gathering information about the quality of children's home lives through observation and parental interviews. Regardless of SES and ethnicity, an organized, stimulating physical setting and parental affection, involvement, and encouragement—especially the extent to which parents talk to infants and toddlers—predict better language and IQ scores in toddlerhood and early childhood.

When parents interact intrusively, bombarding young children with directions, infants and toddlers are likely to be distractible, play immaturely, and do poorly on mental tests.

Infant and Toddler Child Care and Mental Development

Today, more than 60 percent of U.S. mothers with a child under age 2 are employed.

The quality of child care for infants and toddlers—though not as influential as parenting—affects mental development, regardless of SES or ethnicity.

Good child care can reduce the negative impact of a stressed, poverty-stricken home life and can sustain the benefits of growing up in an economically advantaged family.

Many U.S. children from low-income families experience inadequate child care.

Standards for developmentally appropriate practice, devised by the U.S. National Association for the Education of Young Children, specify program characteristics that meet young children's developmental and individual needs.

Early Intervention for At-Risk Infants and Toddlers

Studies indicate that poverty-stricken children are likely to show gradual declines in intelligence test scores and to achieve poorly when they reach school age.

Children participating in interventions designed to break the cycle of poverty for infants and toddlers score higher than untreated controls on mental tests by age 2. The earlier and the longer the intervention, the better the participants' cognitive and academic performance is throughout childhood and adolescence.

Recognizing the power of early intervention, the U.S. Congress has provided limited funding for services directed at infants and toddlers who already have serious developmental problems or who are at risk for problems because of poverty.

nativist perspective

Linguist Noam Chomsky's nativist theory regards language as a unique human accomplishment that is innate: Children are born with a language acquisition device (LAD), containing a set of rules common to all languages, which permits children to understand and speak whichever language they hear in a rule-oriented fashion.

Evidence that childhood is a sensitive period for language acquisition is consistent with nativism. Challenges to Chomsky's theory suggest that it is not a complete account of language development.

(1) Children do not acquire language as quickly as nativist theory suggests; they refine and generalize many grammatical forms gradually, engaging in much piecemeal learning.

(2) For most people, language is housed largely in the left hemisphere of the cerebral cortex, but language areas in the cortex also develop as children acquire language.

interactionist perspective

This view emphasizes interactions between inner capacities and environmental influences.

Some interactionists, applying information-processing theory to language development, assume that children use powerful cognitive capacities to make sense of their complex language environment.

Other interactionists blend this view with Chomsky's nativist perspective. d. Still others take a social-interactionist view, emphasizing the role of children's social skills and language experiences in language development.

cooing and babbling

Around 2 months of age, babies make vowel-like noises called cooing.

Around 6 months, babbling appears: Infants repeat long strings of consonant-vowel combinations.

By around 7 months, babbling starts to include many sounds common in spoken languages; by 8 to 10 months, it reflects the sound and intonation patterns of children's language community.

In hearing-impaired babies, these speechlike sounds are greatly delayed. In deaf infants, they stop, but deaf infants exposed to sign language from birth babble with their hands.

becoming a communicator

Newborns initiate interaction through eye contact and terminate it by looking away.

By 3 to 4 months, infants start to display joint attention, in which the child attends to the same object or event as the caregiver, who often labels it. This skill becomes more accurate around 10 to 11 months and contributes greatly to early language development.

Between 4 and 6 months, caregiver-baby interaction begins to include give-and-take, as in pat-a-cake and peekaboo games.

At the end of the first year, infants use preverbal gestures to direct adults' attention, to influence their behavior, and to convey helpful information.

first words

Infants begin to understand word meanings in the second half of the first year and utter their first words around 1 year. This achievement builds on the sensorimotor foundations Piaget described and on categories that children have formed.

Underextension is a language error in which young children learn words and then apply them too narrowly.

A more common error, overextension, occurs when a word is applied to a wider collection of objects and events than is appropriate.

Overextensions reflect toddlers' sensitivity to categories.

Overextensions illustrate the distinction between language production (the words children use) and language comprehension (the words they understand), which, at all ages, develops ahead of production.

two-word utterances

Young toddlers add to their spoken vocabularies at a rate of 1 to 3 words per week, but between 18 and 24 months, children may add 1 or 2 words per day.

Once toddlers produce 200 to 250 words, they begin to form two-word utterances, called telegraphic speech.

Toddlers rarely make gross grammatical errors, but only gradually do they construct word-order and other grammatical rules.

Individual and Cultural Differences in Language Development

Although children typically produce their first word around their first birthday, the range is large. a. Many studies show that girls are slightly ahead of boys in early vocabulary growth.

The quantity of caregiver-child conversation and richness of adults' vocabularies also play a strong role.

Low-SES children, who receive less verbal stimulation in their homes than higher-SES children, usually have smaller vocabularies.

Two-year-olds' spoken vocabularies vary substantially across languages.

Most toddlers use a referential style of language learning to learn early vocabulary, primarily using words that refer to objects.

Some toddlers use an expressive style, producing many more pronouns and social formulas ("Thank you") because they believe words are for talking about people's feelings and needs.

The two styles are linked to the child's personality and also to culture.

Supporting Early Language Development

Adults in many cultures speak to babies in infant-directed speech (IDS): short sentences with high-pitched, exaggerated expression, clear pronunciation, distinct pauses between speech segments, and repetition of new words in a variety of contexts.

Deaf parents use a similar style of communication when signing to their deaf babies.

The use of IDS builds on the communicative strategies of joint attention, turn-taking, and caregivers' sensitivity to toddlers' preverbal gestures. 4. Parent-toddler conversation strongly predicts language development and reading success during the school years.