Chapter6Infancy

Physical Growth

• Infants grow rapidly in their first year.
• The average baby triples their birth weight by the first year.
• During the second year of life, growth slows down.
• Infants experience two growth patterns: cephalocaudal and proximodistal.
• Cephalocaudal pattern means growth starts from the head and moves down.
• Proximodistal growth pattern starts at the center of the body and moves toward extremities.

Brain Development

• The brain develops extensively during pregnancy and infancy.
• Neurons are present in a brain at birth.
• Neurons process information.
• Myelin sheath insulates nerve cells and makes information processing faster.
• Experience enhances brain development.
• Sleep is essential for brain development.

Language Development

• Crying is present at birth and signals distress.
• Cooing starts around 1-2 months.
• Babbling occurs in the middle of the first year.
• Gestures begin around 8 to 12 months.
• Infants recognize sounds in all languages from birth to 6 months.
• Between 6 months and 1 year, infants focus on specific sounds in their own native language.
• Infants say their first words around 10 to 15 months.
• At 13 months, infants understand around 50 words (receptive language).
• At 18 months, infants can speak around 50 words.
• Between 18 months and 2 years, infants experience a vocabulary spurt and speak around 200 words.
• Biology, vocal apparatus, brain, and language acquisition device (LAD) contribute to language development.
• Aphasia is a loss of ability to use words due to brain damage.
• Broca's area, located in the left frontal lobe, controls muscle movements for speech production.
• Wernicke's area, located in the left hemisphere, plays a role in language comprehension.

Language Development Models

• Behavioral theories are based on the nurturing aspect of development.
• Behavioral theories suggest that language learning is similar to any other learning during childhood.
• According to behavioral theories, language is learned through reinforcement or corrections from adults.

Social and Emotional Development

• Infants are emotional beings.
• They are sensitive to emotional states of others.
• Emotions are feelings or affects that can be positive or negative.
• Emotions are influenced by perceptions.
• Functionalists believe emotions are linked with individual goals.
• Primary emotions are present in humans and animals and appear within the first 6 months.
• Self-conscious emotions require cognition, empathy, jealousy, and embarrassment appear around 1.5 years old.
• Pride, shame, and guilt emerge around 2.5 years old.
• Crying is an infant’s first way of communication.
• There are three types of crying: basic, anger, and pain.
• Quick response to a crying infant is important for developing a strong bond and security.

Imitation

• Immediate imitation is when infants mimic actions right away.
• Delayed imitation is when infants mimic actions after a few hours or days.
• Infants imitate language they hear.
• Language-rich environment promotes imitation.

Physical Development in Infancy

• Infants double their birth weight by 5 months
• Infants need a diet high in fat for brain development
• Poverty negatively impacts infant cognitive development
• Early intervention programs can help infants overcome the negative effects of poverty

Cognitive Development in Infancy

• Language development is a key component of cognitive development
• Toddlers develop language in a predictable pattern: from one-word utterances to two-, three-, and four-word utterances
• Semantics are the set of rules for the meaning of words and phrases
• Pragmatics is the intentional use of language to achieve specific outcomes
• Infants learn language through interaction and modeling
• Biology influences language development, including the evolution of the vocal apparatus and the role of the brain
• Infants are born with a language acquisition device, a biological ability to learn language
• A critical period exists for language learning

Language Development in Infancy

• Crying is present at birth and signals distress
• Cooing begins around 1 to 2 months
• Babbling begins at the middle of the first year
• Gestures begin around 8 to 12 months
• From birth to 6 months, infants recognize most sound changes in any language
• After 6 months, infants learn their own language and gradually lose the ability to recognize sound changes in other languages
• The first words occur between 10 to 15 months
• Infants understand about 50 words at 13 months but are unable to say them until about 18 months
• Children develop a vocabulary spurt from 18 months to 2 years
• From 18 months to 2 years, toddlers use short and precise two-word utterances (telegraphic speech)
• Broca's area is responsible for speech production, while Wernicke's area is responsible for language comprehension
• Noam Chomsky believes humans are biologically prewired to learn language
• There is a critical period for learning language, as demonstrated by the story of Genie, who suffered severe language deprivation

### Infant Growth and Development

• Infants typically grow 3/8 inch (1 centimeter) per month and gain 3 to 5 ounces (85 to 140 grams) per week during their first year of life.
• Most babies triple their birth weight by their first birthday.
• Average North American newborns are 20 inches tall and weigh 7.5 pounds.
• Average 2-year-olds weigh 26 to 32 pounds and are 32 to 35 inches tall (almost half their adult height).
• Growth slows considerably in the second year.

Growth Patterns

• Cephalocaudal pattern: Growth from head down, resulting in "top-heavy" appearance in infants.
• Proximodistal pattern: Growth from the center of the body outwards, starting with the trunk, then arms, and finally hands and fingers.

Brain Development

• The brain develops extensively in utero and during infancy.
• Neurons (nerve cells) are present at birth, responsible for information processing.
• Myelin sheath, a fatty layer that insulates nerve cells, plays a crucial role in speeding up information processing.
• Shaken baby syndrome is a serious risk causing brain swelling and hemorrhaging.
• Experience stimulates brain development, shaping connections among neurons.
• Adequate sleep is critical for promoting brain development during infancy.

Language Development

• Children learn language from competent adults using feedback and reinforcement.
• Conversational patterns are vital for language development:
  • Early babbling helps infants explore sounds and speech patterns.
  • Adults often engage in "talking" with babies, modeling conversation and responding to their babbling.
• Psycholinguistic theory proposes that language acquisition is an innate, biological process possibly driven by a specific brain area.
• Noam Chomsky's Language Acquisition Device (LAD) theory suggests a universal brain module for language learning, allowing children to learn any language.
• Sociolinguistic models emphasize the interplay of nature and nurture, suggesting the brain's language processing areas develop during gestation with environmental sounds as input, but require extensive language experience after birth for full functionality.

Infant Social and Emotional Development

• Infants use crying to communicate their needs, and prompt responses build trust.
• Reflexive smile occurs in the first month after birth, usually during sleep.
• Social smile appears around 2 to 3 months, responding to external stimuli, primarily faces.
• Fear, particularly stranger anxiety, develops around 6 months and intensifies between 9 to 12 months.
• Separation protest, distress upon being separated from a caregiver, peaks at about 15 months.
• Social referencing: Infants use emotional cues from caregivers to interpret social situations.
• Self-soothing is important for transitioning from dependence on caregivers to independence.
• Transitional objects, such as teddy bears or blankets, help infants with this transition.
• Emotional regulation indicates a child's ability to manage emotions.
• Temperament refers to a child's behavioral style and emotional responses:
  • Easy child: Positive mood, easily adaptable.
  • Difficult child: Negative, cries frequently, adapts slowly.
  • Slow-to-warm-up child: Low activity level, less adaptable, subdued mood.
• Goodness of fit: A match between a child's temperament and environmental demands is essential for well-being.
• Trust is crucial for emotional security in infancy.
• Erikson's trust vs. mistrust stage (birth to one year) highlights the importance of a secure and comfortable experience for infants.
• Scaffolding refers to providing appropriate support for a child to learn new skills in a supportive environment.

Childcare and Parenting

• Parental leave policies vary, often lacking paid leave throughout infancy.
• High-quality childcare is characterized by:
  • Small group sizes
  • Low adult-child ratios
  • Teachers with specialized training
  • Sensitive caregiver interactions
• Quality care and limited childcare hours are associated with positive outcomes for children.
• Effective parenting involves:
  • Making good parenting decisions
  • Spending quality time interacting with children
  • Teaching self-soothing strategies
  • Monitoring development
  • Finding appropriate childcare

### Other Important Information

• Swaddling and massage can soothe crying infants.
• Reciprocal socialization refers to the back-and-forth interaction and influence between parents and children.
• Labeling children based on temperament should be avoided.

Test your knowledge on key aspects of infant development, including physical growth patterns, brain development, and language milestones. Understand how these processes unfold during the first years of life and their significance for future growth.