Child Development in the First Two Years

Body Changes in the First Two Years

• Average birth weight: 3.4 kg
• Average birth length: 20 inches
• Babies lose 5-7% of their birth weight in the first few days of life
• Doctors and nurses measure height, weight, and head circumference to monitor growth
• Abnormal growth may signal physical or psychological problems
• Headsparing is a biological mechanism protecting the brain during malnutrition; the brain is the last part of the body to be affected
• Brain weight comprises 75% of adult size in the first two years
• Height and weight reach around 50% of adult size in the first two years

Brain Development

• A neuron is a nerve cell, found in billions in the central nervous system
• The cortex is the outer layer of the brain
• Axons are fibers extending from neurons, transmitting electrochemical impulses between neurons and to dendrites

Child Brain Development

• At birth, babies have 200 billion brain cells (neurons)
• The brain grows at 1.7 grams per day during the first year
• 60% of infants' food energy goes towards brain growth.
• Brain communication across different parts develops rapidly in the first two years.
• By age 2, the brain is about 75% of its adult weight and has 100 trillion cell connections (synapses), which is the maximum in a lifetime.
• DHA and choline are crucial for brain development
• Calcium and Vitamin D are important for bone and teeth

Neurons and Synapses

• Dendrites are fibers extending from a neuron, receiving transmitted electrochemical impulses from other neurons
• A synapse is the intersection between one neuron's axon and the dendrites of another neuron
• Neurotransmitters are brain chemicals carrying information from one neuron to another

Dendritic Spreading

• Dendritic spreading occurs in the initial years of life and is depicted in images showing a clear progression in pattern over time

Synaptic Density

• Synaptic density in the brain increases considerably during infancy and reaches a peak in adolescence.
  • The frontal cortex region, used for reasoning and self-regulation, has a slower development pattern than visual cortex and auditory cortex

Sudden Infant Death Syndrome (SIDS)

• SIDS occurs when babies die unexpectedly from unknown causes in early childhood.
• Risk factors for SIDS include:
  • Low birth weight
  • Heavy bedding
  • Teenage parenthood
  • Maternal smoking
• Putting babies to sleep on their backs can lessen the risk but does not completely eliminate the risk

Adequate Nutrition

• Breastfeeding is vital for infant health and reduces disease risk. Malnutrition increases the risk of diseases.
• Breastfed babies are less prone to allergies, asthma, obesity, and heart disease.
• Breast milk composition changes as the baby grows to accommodate its nutritional needs

Piaget's Sensorimotor Intelligence

• Sensorimotor intelligence is Piaget's concept of how infants process information via senses and motor skills during the first period of development
• Assimilation is Piaget's term for adapting to new experiences by fitting them into existing ideas
• Accommodation is Piaget's term for adapting old ideas to incorporate new experiences
• Object permanence is the understanding that objects exist even when they are out of sight

Stages of Sensorimotor Development

• Primary circular reactions (birth to 1 month): Reflexive behaviors like sucking, looking, and listening are repeated
• Secondary circular reactions (1-4 months): Responses are directed towards objects and involve coordination of reflexes
• Secondary Circular Reactions, Stage 3 (4-8 months): Infants engage in sights and use them to increase their experiences, recognizing connections with others.
• Secondary Circular Reactions, Stage 4 (8-12 months): Purposefully acting on objects to make connections and encourage certain reactions
• Tertiary circular reactions (12-18 months): Experimentation with objects and actions
• Stage Six (18-24 months): Exploring multiple combinations to achieve goals

Information-Processing Theory

• Information processing is a perspective mirroring computer functioning by analyzing how thought mechanisms work in different developmental stages
• Detailing the steps of a thought process provides insights into cognitive mechanisms.
• Information processing research refutes some of Piaget's theories

Sensorimotor Development- Object Permanence

• Understanding that objects continue to exist even when out of sight, developed around 6 months

Visual Cliff

• The visual cliff is an experimental apparatus demonstrating depth perception in babies.

Early Memory

• Classic theories believed infants couldn't form memories in the first year; newer theories show they can if conditions are favorable, especially mirroring real-life situations and high motivation

Language Learning

• Child-directed speech (baby talk) is a high-pitched/simplified communication style
• Babbling (repetition of sounds) develops between 6–9 months
• Naming explosion is a period of rapid vocabulary development involving new words, particularly nouns, which starts around 18 months

Holophrases

• Holophrases are single words used to express complete thoughts

Acquiring Grammar

• Grammar covers the usage of words to produce meaning, including sequence, prefixes, suffixes, intonation, and more

Hypotheses About Language Development

• Infants have to be taught language, and their spontaneous babbling is reinforced
• Parents and caregivers are important teachers of language
• Repetition reinforces word learning, especially when associated with positive experiences

Language Learning is Innate

• The Language Acquisition Device (LAD) is a mental structure aiding language acquisition, encompassing many aspects, including vocabulary, grammar, and intonation

Social Impulse Towards Communication

• Infants communicate in different ways because humans are social beings that depend on each other

Motor Skills

• Early movements are reflexes, not yet skills, reacting involuntarily to stimuli

Motor Development

• Different developmental milestones in motor skills (sitting unsupported, standing alone, walking, running, jumping), demonstrating the progression.