Chapter 5.docx

**Chapter 5** **Cognitive Development in Infancy** **Cognitive Changes** The remarkable cognitive advances that happen in infancy are highly consistent across environments. Of course, 2-year-olds are still a long way from cognitive maturity, but some of the most important steps toward that goal a...

**Chapter 5** **Cognitive Development in Infancy** **Cognitive Changes** The remarkable cognitive advances that happen in infancy are highly consistent across environments. Of course, 2-year-olds are still a long way from cognitive maturity, but some of the most important steps toward that goal are taken in the first two years of life. (See Table 5.1.) **Substage** **Age (in months)** **Primary Technique** **Characteristics** -------------- --------------------- ------------------------------------ ---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- 1 0--1 Reflexes Use of built-in schemes or reflexes such as sucking or looking. Primitive schemes begin to change through very small steps of accommodation. Limited imitation, no ability to integrate information from several senses. 2 1--4 Primary circular reactions As a baby grows, they continually practice basic schemes such as grasping, listening, looking, and sucking. They begin to coordinate these schemes across different senses, for example, turning towards a sound or sucking on anything within reach. However, at this stage, the baby does not yet associate their own actions with external outcomes. 3 4--8 Secondary circular reactions The baby becomes much more aware of events outside his own body and makes them happen again in a kind of trial-and-error learning. Scientists are unsure whether babies this young understand the causal links yet, however. Imitation may occur, but only of schemes already in the baby's repertoire. Beginning understanding of the "object concept" can also be detected in this period. 4 8--12 Coordination of secondary schemes Babies exhibit clear, intentional behavior aimed at achieving a goal. They not only pursue what they want but may also combine two actions to achieve it, such as moving a pillow to reach a toy. They start to imitate new behaviors and transfer information from one sense to another, a process known as cross-modal perception. 5 12--18 Tertiary circular reactions "Experimentation" begins, in which the infant tries out new ways of playing with or manipulating objects. Very active, very purposeful trial-and-error exploration. 6 18--24 Beginning of mental representation Development of use of symbols to represent objects or events. The child understands that the symbol is separate from the object. Deferred imitation can occur only after this point because it requires the ability to represent internally the event to be imitated. **Piaget's View of the First Two Years** Piaget's theory suggests that infants are born with basic schemes such as looking, listening, sucking, and grasping. They assimilate new information into these schemes and accommodate them based on their experiences. This process, known as sensorimotor intelligence, is developed, and refined during the sensorimotor stage. In essence, it's a period of learning and adaptation where infants use their senses and motor abilities to understand the world around them. **Sensorimotor Stage** Piaget's theory outlines two substages in the sensorimotor stage of a newborn's development. In substage 1 (0-1 months), the newborn is focused on the present moment, responding to available stimuli without planning or remembering past events. Substage 2 (1-4 months) marks the start of coordination between various actions like looking, listening, reaching, and sucking, which are crucial for a 2-month-old's exploration of the world. This substage is characterized by primary circular reactions, which are repetitive actions centered around the infant's body, such as accidental thumb sucking that becomes a repeated action due to the pleasure it provides. Each substage represents a significant developmental advancement over the previous one. In Piaget's theory, substage 3 (4-8 months) of the sensorimotor stage involves the baby repeating actions to elicit reactions outside their body, known as secondary circular reactions. For instance, a baby coos to make their mother smile and repeats the action to see the smile again. These are simple links between stimuli and responses. In substage 4 (8-12 months), babies begin to understand causal connections and become more exploratory. They exhibit means-end behavior, where they keep a goal in mind and plan to achieve it. An example is when a baby moves one toy to reach another. The desired toy is the end goal, and moving the other toy is the means to achieve it. In substage 5 (12-18 months) of Piaget's sensorimotor stage, the baby's exploration becomes more focused and experimental due to the emergence of tertiary circular reactions. Instead of merely repeating behaviors, the baby tries out variations. For example, they might experiment with different sounds or facial expressions to elicit a smile from their mother or drop a toy from various heights to observe the resulting sounds or landing spots. Despite this purposeful and experimental behavior, Piaget believed that babies at this stage still do not possess mental symbols to represent objects. Substage 6 (18-24 months) in Piaget's theory is marked by the infant's ability to manipulate mental symbols like words or images. This allows them to solve problems by thinking, without the need for trial-and-error behavior typical of substage 5. Their means-end behavior becomes more sophisticated; for instance, a 24-month-old can figure out how to get a cookie from a jar and overcome obstacles to reach it. If the cookie jar is moved, the toddler will likely find a way to reach it, demonstrating their advanced cognitive abilities. This cognitive development is why caregivers understand that 18- to 24-month-olds cannot be left unsupervised, even briefly. **Object Permanence** Piaget's concept of object permanence is the understanding that objects continue to exist even when they can't be seen. Babies gradually acquire this understanding during the sensorimotor period. The first sign of developing object permanence appears around 2 months of age (substage 2). For instance, if a toy is hidden from a baby of this age, they show surprise when the toy is not there when the obstruction is removed, indicating a basic expectation of the object's permanence. However, at this stage, babies do not actively search for a toy that has been hidden or fallen out of sight. In substage 3 (6-8 months), babies start to look for dropped toys or spilled food, and search for partially hidden objects. For instance, if a toy is partially covered by a cloth, the baby will reach for it, indicating a recognition of the object's existence even when only partially visible. However, if the toy is completely hidden, the baby will not search for it. This behavior evolves in substage 4 (8-12 months), where infants will search for a toy that's entirely hidden by a cloth or screen. By 12 months, most infants understand the concept of object permanence, which is the understanding that objects continue to exist even when they're not visible. **Imitation** Piaget's studies on infants' ability to imitate others revealed that infants could mimic actions they could see themselves perform, like hand gestures, from the first few months of life. However, they couldn't imitate others' facial gestures until substage 4 (8-12 months). This form of imitation seems to require intermodal perception, which combines visual cues from observing another's face and kinesthetic cues from one's own facial movements. Piaget argued that imitation of actions not already in the child's repertoire didn't occur until about 1 year. Deferred imitation, where a child imitates an action at a later time, was only possible in substage 6, as it requires some form of internal representation. There are concerns about the impact of screen time, especially television viewing, on a child's behavior and cognitive development. Some argue that TV viewing habits in early months can negatively affect later social interactions, cognitive growth, and language development. This is a topic of discussion in the context of real-world child development. **Development in the Real World** **What Do Babies Really Learn from Watching Television?** Television viewing is the primary digital activity for families and children up to 14 years old, with parents serving as role models and gatekeepers for young children's viewing habits. Infants are exposed to an average of 5 hours of background television daily, often while playing or eating. By 24 months, television becomes a regular part of 90% of babies' daily routines, despite recommendations against TV viewing for children under 2 years. A longitudinal study found that TV viewing of three or more hours daily increased from 7% in infants under 12 months to 41% in children between 24 and 35 months. The amount of TV watched at 24 to 35 months correlated with the amount watched at age 6. Specifically, 2-year-olds who watched three or more hours of TV daily were three times more likely to watch over three hours daily at age 6. Thus, extensive TV viewing in early childhood predicts greater viewing in later years. The impact of extensive TV viewing during childhood is uncertain. Parents often use television for its perceived educational value, entertainment, and babysitting for babies under 2 years. However, a study found that 3-month-old infants pay minimal attention to TV, but by 10 months, they can imitate what they see and recognize familiar characters. Parents should monitor what infants watch as TV-viewing habits are established at this age. Unmonitored toddlers may prefer fast-paced, often violent cartoons. While TV shows with prosocial themes can positively influence social interactions and altruistic behavior, those with antisocial themes can lead to aggression and stereotype development. Studies indicate that TV viewing by children under 3 may negatively affect cognitive and language development, reading recognition, comprehension, attentional abilities, and cause delayed speech development. In contrast, ordinary toys and household items can be just as beneficial for an infant's learning. Thus, it's suggested that the main thing babies learn from watching TV is the behavior of watching TV itself. **Challenges to Piaget's View** Numerous studies conducted after Piaget's time suggest that he may have underestimated infants' cognitive abilities. For example, by modifying the methods to measure object permanence, researchers discovered that infants younger than those Piaget studied can comprehend object movements. Furthermore, research indicates that the ability to imitate emerges at earlier ages than Piaget initially proposed. **Object Permanence** In Piaget's studies, infants were deemed to have object permanence if they could move a blanket to find a hidden object. However, this method was flawed as infants can't physically perform such tasks until they are 7 to 8 months old. This made it unclear whether younger infants lacked object permanence or were simply unable to demonstrate it due to physical limitations. With the advent of computers, researchers have been able to measure infants' understanding of objects in ways that don't rely on motor skills. These studies track infants' eye movements as objects are moved around. Findings show that babies as young as 4 months exhibit signs of object permanence when tested visually rather than physically. Further studies have shown that most 5-month-olds will look to the other side of a screen when a moving object disappears behind it, indicating they hold a mental representation of the hidden object - the essence of object permanence. However, this understanding in younger infants is typically tied to the specific experimental situation. In contrast, babies nearing or past their first birthday understand object permanence well enough to apply it in various situations, such as playfully hiding and finding objects. While Piaget proposed that babies come with a set of sensorimotor schemes and construct their understanding of the world through experience, recent theories suggest that the development of object permanence is more about elaboration than discovery. Newborns may already have a significant awareness of objects as separate entities that follow certain rules. Research indicates that babies pay more attention to the relationships between events than Piaget's model suggested. However, it's agreed that a baby doesn't arrive with a complete knowledge of objects or a fully developed ability to experiment with the world. **Imitation** Piaget's sequence of imitation has been largely supported. Imitation of hand movements or object-related actions improves steadily from 1 or 2 months of age, while imitation of two-part actions develops later, around 15 to 18 months. However, there are exceptions: infants imitate some facial gestures in the first weeks of life, and deferred imitation seems to occur earlier than Piaget suggested. Research has found that newborns will imitate certain facial gestures, particularly tongue protrusion, if the model maintains the gesture for a significant period, possibly up to a minute. This early imitation is notable and aligns with observations that very young babies are capable of tactile-visual intermodal transfer, or perception. While most studies support Piaget's model of deferred imitation, some research suggests that infants as young as 6 weeks can defer imitation for a few minutes, extending to about 10 minutes by 6 months. Furthermore, babies as young as 9 months can defer their imitation for up to 24 hours, and by 14 months, toddlers can recall and imitate actions up to two days later. These findings are significant as they demonstrate that infants can learn specific behaviors through modeling, even without an immediate chance to imitate. The results also suggest that babies might be more skillful than Piaget assumed. It's clear that more abilities may be innate from the start and develop continuously, rather than in discrete stages, throughout infancy. **Alternative Approaches** Challenges to Piaget's understanding of infant cognition have led researchers to explore object permanence within the broader context of infants' comprehension of objects and their behavior, referred to as the 'object concept'. Elizabeth Spelke and her colleagues have conducted extensive research on the development of the object concept. Spelke proposes that babies are born with inherent assumptions that guide their interactions with objects. One such assumption, termed the 'connected surface principle', is that when two surfaces are connected, they are part of the same object. For example, all sides of a textbook are understood to be connected, forming a single, solid object. In her early studies, Elizabeth Spelke habituated 3-month-old babies to displays of either one or two objects. After this habituation phase, she showed the babies two objects touching each other, forming a shape like a rectangle. The babies who had been habituated to two-object displays showed renewed interest, indicating they perceived this as a different display, likely seeing it as a single object. However, babies who had been habituated to one-object displays didn't show this renewed interest. In later experiments, Spelke used a research strategy called 'violation-of-expectancy'. In this approach, an infant is habituated to a display showing the movement of an object. Then, the infant is shown another display where the object moves in an unexpected way. In these experiments, babies were largely uninterested in the consistent condition but showed a sharp increase in interest when the movement was inconsistent with their expectations. These findings suggest that very young infants' understanding of the rules governing the relationships among objects was more advanced than what Piaget's theory proposed. Specifically, they seem to have a better grasp of object permanence and the principles of cause and effect at a younger age than previously thought. The process of an infant recognizing that an object seen at one time is the same object viewed at another time is known as object individuation. Research by Fei Xu and colleagues suggests that infants use three broad categories to individuate objects: 1. **Spatiotemporal Information**: Active in infants at 4 months of age, this involves information about the location and motion of objects. 2. **Object's Property Information**: Apparent in 10-month-old infants, this is based on the perceptual qualities of an object, such as color, texture, and size. For instance, an infant would know that a red ball is different from a green ball viewed on a separate occasion. 3. **Awareness of Distinct Kinds of Objects**: The last system to develop, this involves the recognition of different types of objects, such as a duck versus a ball. This adult-like ability first becomes apparent in infants by 9 to 12 months of age. These findings, along with later studies on object individuation, continue to provide insights into how infants learn, represent, and reason about physical objects and events in their environment. **Learning, Categorizing, and Remembering** Learning generally refers to the permanent changes in behavior that result from experience. From birth, babies show signs of learning as their behaviors change in response to environmental influences. Additionally, babies actively structure their interactions with these influences, as demonstrated by research on categorization and memory. Intelligence measures assist healthcare professionals in identifying infants who need special interventions to aid their cognitive development. **Conditioning and Modelling** Learning of emotional responses through classical conditioning can start as early as the first week of life. In her research, pediatrician Mavis Gunther found that inexperienced mothers often held their nursing newborns in a way that blocked the babies' nostrils with the breast, causing a smothering sensation. As a result, the babies reflexively turned away from the breast. In future nursing sessions, babies who had experienced this sensation refused to nurse on the side associated with the smothering sensation. Gunther hypothesized that this was a case of classical conditioning. She developed an intervention based on stimulus-response learning principles to help babies "unlearn" the response of turning away from the breast they associated with the smothering sensation. Newborns learn through operant conditioning, as evidenced using pacifier-activated lullaby (PAL) systems in neonatal intensive care units. These systems reward infants with music when they suck on specially designed pacifiers, improving their sucking reflexes and promoting weight gain. This indicates that the neurological wiring needed for operant learning is present before birth. The mother's voice is a particularly effective reinforcer for babies. Infants also learn by observing models. In a study, 10-and 12-month-olds who observed an adult demonstrating how to find a toy were more proficient at finding the toy than those who didn't observe the adult. This proficiency was more pronounced in older infants. By 14 months, infants can distinguish between successful and unsuccessful models and are more likely to imitate successful ones. In a variation on modeling, 9-and 11-month-old infants showed more interest in watching adults play with an object they had previously played with themselves, suggesting a relationship between infants' actions and their perception of others' actions. This indicates that infants' prior experience with an object increases their interest in others' interactions with the same object. **Schematic Learning** Schematic learning refers to the process of organizing experiences into expectancies or familiar patterns, often termed as schemas. These schemas are developed over time through repeated exposure to specific experiences. Once established, they aid babies in differentiating between what is familiar and what is unfamiliar. Schematic learning involves categories, and research suggests that infants as young as 7 months actively use categories to process information. For instance, a 7-month-old baby habituated to a sequence of animal pictures won't show surprise when shown another animal picture but will show surprise when shown a human picture after a sequence of animal pictures. However, the understanding of categories in 7-month-olds is not fully developed. They don't understand the difference between lower-level and higher-level categories. For example, both "dogs" and "animals" are categories, but "animals" is a higher-level category that includes "dogs". This type of category is referred to as a superordinate. Infants respond to superordinate categories like "animals" before they react to basic-level categories like "dogs". In other words, 7- or 8-month-olds view "animals" and "furniture" as different categories, but not "dogs" and "birds". However, by 12 months, infants appear to understand both types of categories. While 12-month-olds understand basic-level categories like "dogs" and "birds", they don't yet comprehend that these categories are nested within a larger, superordinate category like "animals". This understanding of hierarchical categorization, where smaller categories are nested within larger ones, begins to emerge in 2-year-olds. However, a full understanding of this type of categorization typically doesn't develop until around age 5. This development is closely linked to language development and experiences with using words as category labels. **Memory** While it's generally believed that forming memories during sleep is impossible, research indicates that newborns can remember auditory stimuli they're exposed to while sleeping. This is one of several unique characteristics of infant memory. Studies by Carolyn Rovee-Collier and her team have demonstrated that babies as young as 3 months old can remember specific objects and their interactions with them for up to a week. In these studies, a mobile is hung over a baby's crib and the baby's leg is connected to the mobile with a string. This setup allows the baby to move the mobile by kicking. Babies quickly learn this cause-and-effect relationship, doubling or tripling their kick rates within 3 to 6 minutes. The researchers then test the baby's memory by hanging the same mobile over the crib a few days later without attaching the string to the baby's foot. If the baby kicks rapidly upon seeing the mobile, it indicates that they remember the previous interaction. This behavior has been observed in 3-month-old babies even after a delay of a week. Research has shown that infants as young as 3 months can form associations between objects that appear together in their environment. By 6 months, infants can form new associations with their memories of objects, suggesting that their observations can trigger memories and enable them to combine them in new ways. This underscores the impact of early experiences and diverse environments on cognitive development. These findings indicate that infants are more cognitively advanced than previously thought by developmentalists and Piaget. They also support Piaget's theory of infants' progressively improving memory abilities. For instance, 2-month-olds can remember their kicking action for a day, 3-month-olds for over a week, and 6-month-olds for more than two weeks. However, these early memories are strongly context dependent. Even slight changes in context, such as a different cloth around the crib, can cause 6-month-olds to fail to recognize or remember the mobile. Despite this, lost infant memories can be "reactivated" with cues that remind the baby of the association between a behavior and a stimulus. Therefore, while babies do have more memory capacity than Piaget suggested, their memories are highly specific and become less tied to specific cues or contexts as they age. **Measuring Intelligence in Infancy** Psychologists have developed various tools to measure intelligence in children and adults, which is defined as the ability to absorb information and adapt to the environment. However, measuring intelligence in infants is challenging. The Bayley Scales of Infant and Toddler Development is a widely used test that assesses cognitive, language, and motor development. For instance, 3-month-old infants are tested on their ability to reach for a ring, while older babies are observed for their ability to put cubes in a cup or build a cube tower. The test also includes cognitive tasks, such as covering a toy with a cloth and observing if the child uncovers it, which measures object permanence in 8-month-old infants. The latest version of the Bayley Scales also evaluates adaptive behavior and social-emotional skills. Unlike its predecessors, the Bayley-III has proven to be a reliable predictor of preschoolers' intelligence test scores. However, the primary function of the Bayley Scales is to identify infants and toddlers requiring early intervention due to developmental delays or neurological impairments. A limitation of the Bayley-III is its tendency to underestimate the severity of impairments in these children. Therefore, it's recommended to use multiple tests and measures for assessing neurodevelopmental outcomes until new norms for the Bayley-III are established. Some developmentalists believe that habituation tasks, which measure how quickly an infant loses interest in repeated stimuli, can be effective in assessing infant intelligence. The speed of habituation may indicate the efficiency of the infant's perceptual/cognitive system and its neurological foundations. If such efficiency is a characteristic of intelligence, differences in habituation rates in early life could predict later intelligence test scores. Research has found links between measures of habituation in infants and later intelligence test scores. Psychologist Joseph Fagan developed the Fagan Test of Infant Intelligence, a standardized test of habituation rate. Fagan suggests that tests of habituation rate, also known as novelty preference and visual recognition, are suitable for infants who cannot respond to conventional tests like the Bayley Scales. For instance, infants with cerebral palsy may not be able to perform many of the tasks required by the Bayley Scales, but they can view visual stimuli and exhibit habituation. Research has shown that the Fagan Test is a useful measure of cognitive function in such special populations. Predicting future IQ based on infant measures is complex, as intelligence, while generally consistent from age two onwards, can be influenced by various factors. Intelligence is somewhat malleable and can be enhanced by early educational interventions or limited by adverse conditions such as socioeconomic disadvantages and environmental risks. Exposure to neurotoxins, including naturally occurring elements like fluoride, is one such environmental risk. While fluoride in acceptable concentrations is added to water supplies for dental health and proper bone development in children, excessive amounts can lead to dental or skeletal fluorosis and lower IQ scores. In Canada, fluoride levels in tap water and urine are typically well below the maximum acceptable levels, but these can vary across regions. The impact of neurotoxins, including substances like pesticides and industrial chemicals such as arsenic, lead, and methylmercury, on neurological and intellectual development is still being studied. Researchers are advocating for a global response to understand the effects of early life exposure to known neurotoxins on brain and cognitive development. **The Beginnings of Language** While many people associate the onset of language with a baby's first words around 12 months of age, numerous crucial developments occur before this milestone. Various theoretical perspectives attempt to explain these developments, often rooted in the classic nature-nurture debate. The remarkable progress children make in language development in their early years has been interpreted from both behaviourist and nativist perspectives, and as part of broader cognitive development. **Theoretical Perspectives of Language Development** +-----------------------+-----------------------+-----------------------+ | **Theory and | **Main Idea** | **Example** | | Proponent(s)** | | | +=======================+=======================+=======================+ | Behaviourist | Behaviourist theories | While babbling, | | | of language | babies accidentally | | B.F. Skinner (1957) | development claim | make sounds that | | | that infants learn | somewhat resemble | | | language through | real words as spoken | | | parental | by their parents. | | | reinforcement of | Parents hear the | | | word-like sounds and | word-like sounds and | | | correct grammar. | respond to them with | | | | praise and | | | | encouragement, which | | | | serve as reinforcers. | | | | Thus, word-like | | | | babbling becomes more | | | | frequent, while | | | | utterances that do | | | | not resemble words | | | | gradually disappear | | | | from babies' | | | | vocalizations. | +-----------------------+-----------------------+-----------------------+ | Nativist | Nativist theories of | In effect, the LAD | | | language development | tells infants what | | Noam Chomsky (1959) | state that an innate | characteristics of | | | language processor | language to look for | | | called the language | in the stream of | | | acquisition device | speech to which they | | | (LAD), which contains | are exposed. Simply | | | the basic grammatical | put, the LAD tells | | | structure of all | babies that there are | | | human language, | two basic types of | | | guides children's | sounds---consonants | | | comprehension and | and vowels---and | | | production of | enables them to | | | language. | properly divide the | | | | speech they hear into | | | | the two categories so | | | | that they can analyze | | | | and learn the sounds | | | | specific to the | | | | language they are | | | | hearing. | +-----------------------+-----------------------+-----------------------+ | Interactionist | Interactionists | From the beginning of | | | assert that infants | language, the child's | | -Melissa Bowerman | are biologically | intent is to | | (1985) | prepared with | communicate, to share | | | perceptual and motor | the ideas and | | -Michael Tomasello | readiness to attend | concepts in his head. | | (1999, 2008) | to and produce | He does this as best | | | language and that | he can with the | | -Lev Vygotsky (1962) | language development | gestures or words he | | | is a subprocess of | knows, and he learns | | -Janet Werker (1989, | neuro-cognitive | new words when they | | 1991, 2018) | development. They | help him communicate | | | believe that social | his thoughts and | | | interactions are | feelings. | | | critical to language | | | | development. | | +-----------------------+-----------------------+-----------------------+ **Influences on Language Development** Our understanding of how the environment influences language development has significantly improved since the historic debate between Skinner and Chomsky in the 1950s. The interactionist approach, which emphasizes the role of environmental influences during different stages of language development, has gained prominence. One such influence is 'infant-directed speech' (IDS), a unique way adults and older children communicate with infants, characterized by a higher pitch and repetition with minor variations. Adults also 'expand' or 'recast' a child's sentences into longer, grammatically correct forms. For instance, if a child says "Mommy sock," the mother might respond with "Yes, this is Mommy's sock." These techniques play a crucial role in a child's language development. Developmentalists believe that Infant-Directed Speech (IDS) plays a significant role in language development. Babies, even a few days old, can distinguish between IDS and adult-directed speech, and they prefer IDS regardless of the speaker's gender or the language used. IDS helps infants identify specific sounds in their mother's speech that are crucial to the language they are learning. IDS also contributes to grammar development. The high-pitched quality of IDS attracts babies, and the simplicity and repetitiveness of the speech help them recognize repeating grammatical forms. Children are more likely to imitate a correct grammatical form if they hear their sentences recast in that form. Experimental studies confirm that children exposed to higher rates of specific types of recast sentences learn the modeled grammatical forms more quickly. IDS has also been shown to facilitate long-term word recognition. Children whose parents frequently engage them in conversation, read to them, and use a diverse vocabulary tend to develop language skills earlier, have larger vocabularies, use more complex sentences, and learn to read more easily when they start school. Early language experiences, particularly conversational turn-taking interactions between 18 and 24 months of age, are associated with better developmental outcomes in school-aged children, including higher IQ and language skills. However, these findings raise concerns about Indigenous children, who typically score lower on language skills assessments than mainstream children. It's crucial to distinguish between language differences and language delays. Assessment tools based on mainstream Canadian norms may underestimate the language skills of Indigenous children due to cultural differences in child-rearing practices. Many Indigenous children grow up in environments that value respectful, non-verbal communication and emphasize comprehension over vocabulary. Additionally, many Indigenous children grow up speaking a nonstandard variant of English or French or one of the 70+ Indigenous languages spoken in Indigenous homes across Canada. This can make transitioning to an English or French language school setting challenging. Therefore, culturally valid, and unbiased assessment tools and methods, as well as culturally focused speech-language facilitation and interventions, are important for preparing Indigenous children for school. **Early Milestones of Language Development** Children, irrespective of their cultural backgrounds, generally follow a similar pattern of language development, whether they are learning one or two languages. From birth to about one month, an infant's most common sound is crying, but they also make other sounds like fussing, gurgling, and sounds of satisfaction. Over the next few months, the variety of sounds a baby can make increases significantly. Each of these early vocalizations, even those that may seem insignificant, contributes uniquely to the language skills that all healthy children develop in their first few years. **First Sounds and Gestures** Babies start making laughing and cooing vowel sounds at around 1 or 2 months, often varying in tone, volume, and pitch. Sounds like this are usually signals of pleasure. By about 4 months, an infant's voice pitch can predict their voice pitch in later childhood, with higher-pitched cries indicating higher-pitched voices and vice versa. Around 6 or 7 months, babies begin to produce consonant sounds, often combined with vowel sounds to form syllables. They tend to repeat these sounds, a pattern known as babbling, which constitutes about half of their non-crying sounds from 6 to 12 months. The left side of the brain, which controls the right side of the body, is also where language capacity resides in most people. Researchers at McGill University studied the mouth movements of 5-to 12-month-old babies and found that they displayed a right-mouth bias when babbling, like the right-mouth asymmetry seen in adults when they talk. This suggests that babbling is not just a generic oral motor behavior but is linked to the beginnings of language production. Babbling is an important part of preparing for spoken language. Infants' babbling gradually acquires some of the intonational patterns of the language they hear, a process referred to as "learning the tune before the words". Infants develop at least two "tunes" in their babbling. Babbling with a rising intonation at the end of a string of sounds seems to signal a desire for a response, while a falling intonation requires no response. When babies first start babbling, they typically produce a variety of sounds, including some not part of the language they hear. However, around 9 or 10 months, their sound repertoire narrows to the sounds they hear regularly, with nonheard sounds dropping out. This suggests that babbling is part of a connected developmental process that begins at birth, although it doesn't prove that babbling is necessary for language development. Around the same age, babies start using a kind of gestural language, demanding, or asking for things using gestures or combinations of gestures and sounds. For instance, a 10-month-old baby might stretch and reach for a favorite toy while making whining or whimpering sounds. Interestingly, infants use gestures this way whether they're exposed to spoken language or sign language. They also start participating in gestural games like "patty cake," "soooo big," and "wave bye-bye" around this age. **Word Recognition** Research indicates that babies start storing individual words in their memories around 6 months of age. By 9 or 10 months, most babies understand the meanings of 20 to 30 words, a skill known as receptive language. Over the next few months, the number of words they understand increases significantly. In a study where mothers were asked about their babies' understanding of various words, it was reported that 10-month-olds understood an average of about 30 words, while 13-month-olds understood nearly 100 words. **Research Report** **Setting the Stage for Language Acquisition and Word Learning** Just as there are developmental milestones in motor development, there are also stages in speech perception and language development. Researchers have found that newborns have a neural predisposition for language acquisition, which undergoes two transitional stages: a "reorganization of communication sounds" and a "reorganization in infants' use of phonetic detail". Newborns show an innate bias for speech and can distinguish between human speech sounds and non-speech sounds. By 2½ months, infants prefer listening to complex speech sounds over equally complex non-speech sounds. At 4 to 6 months, infants are sensitive to all essential speech sounds, indicating readiness to learn any human language. However, a perceptual transition occurs by 10 to 12 months, where infants, like adults, can no longer distinguish subtle language sounds beyond their dominant language. This loss of sensitivity to universal speech sounds is related to perceptual filtering and can be recovered under experimental conditions. A study comparing bilingual and monolingual infants found that both groups responded similarly to French and English words at 6 to 8 months. However, by 10 to 12 months, bilingual infants could distinguish phonetic sounds in two languages, while monolingual infants could only distinguish sounds in one language. These studies suggest a shift in perceptual sensitivity away from universal speech sounds from birth to 12 months, facilitating language acquisition and word development. Stager and Werker (1997) conducted an experiment to understand the developmental stages of infants in terms of speech and language comprehension. They found that **14-month-old infants** could associate words with objects but were unable to detect subtle differences in speech sounds. On the other hand, **8-month-old infants** could discern fine differences in speech sounds but were not yet able to associate words with objects. This suggests that at 8 months, infants are still learning the basic sounds of their language, and by 14 months, having mastered these sounds, they begin to learn word-object associations. This ability, which emerges at 14 months, is a crucial step towards the rapid language and vocabulary acquisition that typically happens around 18 months of age. From birth, infants are sensitive to subtle differences in speech sounds and are equipped to categorize words into two groups: grammatical and lexical. A variety of sound cues enable infants to make this distinction. Grammatical words, which are mainly structural (like articles, prepositions, and auxiliaries), typically have a short vowel duration and a simple syllable structure. Examples include "its", "the", "in", and "you". This ability to differentiate word categories is an inherent skill in infants. Lexical words, which include nouns, verbs, adjectives, and adverbs, carry significant meaning. They are usually longer, have full vowels, and possess a more complex syllable structure. Examples of lexical words are "mommy", "new", "bounced", and "great". This contrasts with grammatical words, which are shorter and have simpler syllable structures. Shi and Werker (2001) found that infants as young as 6 months old show a clear preference for lexical words, which are words with significant meaning like nouns, verbs, adjectives, and adverbs. This innate preference might explain why infants learn and understand lexical words before they grasp grammatical words. The natural inclination towards lexical words helps infants focus on meaningful words, preparing them for language acquisition. This inherent ability to distinguish between lexical and grammatical words is a crucial initial step in understanding the structure of human languages. The process of how infants distinguish individual words from continuous speech is a complex task. Linguists suggest that children manage this through inherent biases or constraints (Archibald & Joanisse, 2013; Räsänen, 2012). For instance, children might naturally assume that words refer to either objects or actions, but not both. This built-in bias aids in the process of word learning. Infants learn to identify words by understanding a language's patterns of word stress. They can distinguish between stressed and unstressed syllables as early as 7 months old, using this as a cue to identify words. For instance, in English, first-syllable stress (like in "market") is more common than second-syllable stress (like in "balloon"). So, when English-learning infants hear a stressed syllable, they may assume a new word is starting, helping them identify many individual words. Furthermore, the onset of meaningful gestures, the shift of babbling towards the sounds of the heard language, imitative gestural games, and the initial comprehension of individual words all indicate a series of developmental changes that typically converge around 9 or 10 months of age. This suggests that the child is beginning to understand the process of communication and is attempting to communicate with adults. **The First Words** In language learning, comprehension often precedes production. This is evident in infants who, by 9-10 months, understand more words than they can speak. The emergence of expressive language, the ability to produce and respond to meaningful words, typically occurs around 12-13 months. A baby's first word, eagerly anticipated by parents, can be easy to overlook. Linguists define a word as any sound or set of sounds consistently used to refer to something. Thus, if a child uses "ba" consistently to refer to her bottle, it's considered a word, even if it's not a recognized word in English. Children's earliest words are often used in specific contexts and require many repetitions for learning. In the initial six months of word usage, a child may learn as few as 30 words, each associated with specific situations. At this stage, children may not fully understand that words are symbolic and represent objects or events. Before using two words together in speech, very young children often combine a single word with a gesture to convey a "two-word meaning". For instance, a child pointing to his father's shoe and saying "Daddy" is conveying "Daddy's shoe". These combinations of word and gesture, known as holophrases, are frequently used by children between 12 and 18 months of age. Between 16 and 24 months, children typically experience a "naming explosion", a period of rapid word acquisition. This phase follows an initial slow period of word learning. During the naming explosion, children quickly learn new words, often with minimal repetition, and apply these words in various contexts. According to a study, the average vocabulary of a 16-month-old is about 50 words, which expands to approximately 320 words by the age of 24 months. During the early phase of rapid vocabulary growth, children primarily learn names for things or people, with action words appearing later. By age 2, about two-thirds of the words children know are nouns, and only 8.5% are verbs. Infants may not consistently associate words with actions until about 18 months. However, the prevalence of nouns over verbs in natural speech is a significant factor in language acquisition. Infants exposed to unfamiliar languages can distinguish between object names and other words based on their frequency in speech. This suggests a built-in strategy in infants to learn the most frequent words first, typically nouns, before focusing on others. **The First Sentences** Research indicates that children start forming sentences when they have a vocabulary of about 100 to 200 words, typically between 18 and 24 months of age. These initial sentences are short, usually two or three words, and simple. This pattern, termed "telegraphic speech" by researcher Roger Brown, often includes nouns and verbs but lacks grammatical markers or inflections. For instance, early English learners usually don't use the "-s" for plurals or "-ed" for past tense. Even at the earliest stages, children form sentences based on certain rules, focusing on specific words, and arranging them in particular orders to convey various meanings. For instance, they often use two-noun sentences like "Mommy sock" or "sweater chair". The meaning of such sentences, like "Mommy sock" could be "This is Mommy's sock" or "Mommy is putting a sock on my foot", depends on the context in which they are used. **Individual Differences in Language Development** The sequences of development of language, which are shown in Table 5.3, are accurate on the average, but the speed with which children acquire language skill varies widely. One factor influencing this rate is the number of languages to which a child has daily exposure. (See Development in the Real World.) **Table 5.3 Language Development in the First Two Years** **Age** **Milestone** --------------- ---------------------------------------------------------------------------------------------------------------------------- 2--3 months Makes cooing sounds when alone; responds with smiles and cooing when talked to 4--5 months Makes various vowel and consonant sounds with cooing 6 months Babbles; utters phonemes of all languages 8--9 months Focuses on the phonemes, rhythm, and intonation of language spoken in the home; has receptive vocabulary of 20 to 30 words 12 months Expressive language emerges; says single words 12--18 months Uses word-gesture combinations combined with variations in intonation (holophrases) 16--24 months Displays rapid vocabulary growth (naming explosion) 18--20 months Uses two-word sentences (telegraphic speech); has expressive vocabulary of 100 to 200 words **Development in the Real World** **One Language or Two?** About 18% of Canadians are bilingual in English and French, and due to immigration trends, one in five Canadians speaks one of 200 other languages. Bilingualism offers social and economic benefits, but also presents cognitive advantages and challenges. On the upside, bilingual children, as per a study by Nicoladis and Genesee, start speaking in the parent's dominant language with the respective parent around the age of 2. Unlike monolingual children, bilingual children can use two terms for the same object. Bilingualism is associated with better metalinguistic ability, improved working memory tasks performance, and greater attention focus on language tasks, aiding in the initial stages of reading. On the downside, inconsistent exposure to a second language can lead to uncertain language patterns and competence levels. Bilingual children's proficiency is influenced by their exposure to different languages from various sources. To develop functional competence in both languages, they need regular and abundant exposure to both languages. Early exposure to two languages leads to higher language competence and mastery. Bilingual children with equal fluency in two languages face few learning problems in school. However, most bilingual children do not achieve equal fluency in both languages, which can slow their thinking in the less fluent language and put them at an educational disadvantage if schooled in that language. Therefore, parents considering bilingualism should ensure they can support their children's fluency in both languages. The critical period for language acquisition starts early and extends to late adolescence (\~17 years), after which it gradually declines. Bilingualism in adulthood offers significant benefits, including a protective effect against Alzheimer's disease onset, as found by Canadian researchers. Therefore, bilingual parents need to weigh the pros and cons of bilingualism to make an informed decision about the linguistic environment for their children. **Differences in Rate** Children's language development varies, with some starting to use words at 8 months and others at 18 months. Some may not form two-word sentences until they're 3 years or older. Most late-talking children catch up, with 97% reaching average language development by age 6. Those who don't catch up often have poor receptive language development and may lag in cognitive development. If a child significantly lags in understanding and speaking language, professional help is recommended. Research indicates that about 13% of Canadian toddlers are late talkers. Factors associated with this include a family history of late talking or diagnosed speech-language delay and being male. These findings suggest a biological predisposition for delayed speech. Infants who have language-based social interactions, such as being read to from an early age, daily book interaction, interactive play, and primary care in child-care centres, are less likely to be late talkers. **Language Development Across Cultures** Studies across various language communities, including Turkish, Serbo-Croatian, Hungarian, Hebrew, Japanese, Kaluli, German, and Italian, have found commonalities in language development. Globally, babies coo before they babble, understand language before speaking, and start using their first words around 12 months. Holophrases typically precede telegraphic speech, which begins around 18 months. However, the specific word order in early sentences varies across languages. Some languages commonly use a noun/verb sequence, while others use a verb/noun sequence. The learning order of specific inflections also varies. For instance, Japanese children start using pragmatic markers, which indicate feeling or context, very early. The word "yo" is used at the end of a sentence when the speaker faces resistance from the listener, and "ne" is used when the speaker expects agreement. These markers are used much earlier than other types of inflections in other languages. In some languages, there is no simple two-word sentence stage without inflections. For instance, Turkish-speaking children use the full set of noun and verb inflections by age 2, skipping the stage of using uninflected words. While their language use is simple, it is rarely ungrammatical from an adult\'s perspective. **List of Key Terms** **Cooing:** making repetitive vowel sounds, particularly the uuu sound. **Babbling**: the repetitive vocalizing of consonant--vowel combinations by an infant. **deferred imitation:** imitation that occurs in the absence of the model who first demonstrated it. **expressive language**: the ability to use sounds, signs, or symbols to communicate meaning. **grammatical words**: words that pertain to the rules of language and proper sentence construction, such as articles, prepositions, and auxiliaries. **Holophrases**: combinations of gestures and single words that convey more meaning than just the word alone. **infant-directed speech (IDS)**: the simplified, higher-pitched speech that adults use with infants and young children. **Inflections**: grammatical markers attached to words to indicate tense, gender, number, and the like, such as the use of the ending -ed to mark the past tense of a verb in English. **Intelligence**: the ability to take in information and use it to adapt to the environment. **Interactionists**: theorists who argue that language development is a subprocess of general cognitive development and is influenced by both internal and external factors. **means--end behaviour**: purposeful behaviour carried out in pursuit of a specific goal. **language acquisition device (LAD)**: an innate language processor, theorized by Chomsky, that contains the basic grammatical structure of all human language. **lexical words**: words with a high level of meaning, such as nouns, verbs, adjectives, and adverbs. **naming explosion**: the period when toddlers experience rapid vocabulary growth, typically beginning between 16 and 24 months. **object concept**: an infant's understanding of the nature of objects and how they behave. **object individuation**: the process by which an infant differentiates and recognizes distinct objects based on her mental images of objects in the environment. **object permanence**: the understanding that objects continue to exist when they can't be seen. **primary circular reactions**: Piaget's phrase to describe a baby's simple repetitive actions in substage 2 of the sensorimotor stage; the actions are organized around the baby's own body. **receptive language**: comprehension of spoken language. **schematic learning:** organization of experiences into expectancies, called schemas, which enable infants to distinguish between familiar and unfamiliar stimuli. **secondary circular reactions:** Piaget's phrase to describe the repetitive actions in substage 3 of the sensorimotor period; the actions are oriented around external objects. **sensorimotor stage**: Piaget's first stage of development, in which infants use information from their senses and motor actions to learn about the world. **telegraphic speech**: simple two- or three-word sentences that usually include a noun and a verb. **tertiary circular reactions**: deliberate experimentation with variations of previous actions that occurs in substage 5 of the sensorimotor period. **violation-of-expectancy**: a research strategy in which researchers move an object in one way after having taught an infant to expect it to move in another.