8.2 Prenatal, Infancy, and Early Childhood

Introduction

• Inquiry into human change during prenatal development, infancy, and early childhood.

• Development commences before birth, characterized by rapid changes and vulnerability as individuals begin their developmental journey.

Prenatal Development Stages

• Describes the three stages of prenatal development: germinal, embryonic, and fetal.

Germinal Stage

• Duration: Begins at conception and lasts for two weeks.

• Process:

  • Begins with fertilization where one sperm cell merges with an ovum (egg) to form a zygote.

  • Zygote: A single microscopic cell containing 46 chromosomes.

  • Mitosis: The process by which the zygote divides (2 cells, then 4, then 8, etc.). Each cell retains 46 chromosomes.

  • Multiples: Occurs when the cell division does not follow the typical process leading to monozygotic (identical) twins if the mass of cells splits completely, or dizygotic twins if two eggs are fertilized.

  • Example: Monozygotic twins are the same sex with identical features, while dizygotic twins arise from separate fertilizations.

Embryonic Stage

• Commences about two weeks after conception when the fertilized egg attaches to the uterine wall.

• Duration: Lasts from about the second week to the eighth week post-conception.

• Developmental Milestones:

  • Formation of major body organs and systems, including the nervous system, heart, limbs, eyes, and external genitalia.

Fetal Stage

• Duration: Lasts from about the eighth week until birth.

• Characterized by significant growth:

  • Length increases approximately 20 times.

  • Weight grows from about one ounce to an average of over seven pounds at birth.

  • Neural Development: A lifetime's worth of brain neurons are generated during this stage.

• Milestones during the fetal period:

  • The age of viability occurs around 22 weeks, the point where the fetus can survive if born prematurely.

  • Sensitive periods where the fetus is particularly vulnerable to damage that could affect development.

Infancy

• Characterization of infancy:

  • Common activities include eating, sleeping, crying, and toileting.

• Health Assessment: Conducted using the Apgar scale.

  • Apgar Scale Indicators (1952):

  • Appearance (color)

  • Pulse (heart rate)

  • Grimace (facial expression and reflexes)

  • Activity (muscle tone)

  • Respiration (breathing)

  • Historical context reveals limitations of the scale, particularly regarding its applicability to infants of color (e.g., poor description of dark-skinned infants).

Neural Development

• At birth, approximately 100 billion neurons present.

• Importance of Neural Connections:

  • Rapid formation of synaptic connections occurs in newborns, leading to foundational skills such as movement, language, and memory.

  • Synaptic pruning begins after age three, strengthening frequently used connections while eliminating unused ones.

Cognitive Development

• Overview of major theories from notable developmental psychologists:

  • Jean Piaget

  • Lawrence Kohlberg

  • Lev Vygotsky

Piaget’s Theory of Cognitive Development

• Concept: Children are cognitive explorers who evolve from simple to increasingly abstract thinking.

• Stages of Cognitive Development:

  • Stage One: Sensorimotor (Birth to 2 years)

  • Interaction primarily through senses and motor movements.

  • Major Achievement: Object permanence (understanding that objects continue to exist even when out of sight).

  • Experiment 1: Object permanence tested by hiding a toy and observing the infant's reaction.

  • Stage Two: Preoperational (2 to 7 years)

  • Development of symbolic thinking and language, but struggles with advanced concepts.

  • Example: Egocentrism demonstrated through Piaget's mountain perspective experiment.

  • Experiment 2: Testing egocentrism via telephone conversation, indicating if the child understands another's perspective.

Criticisms of Piaget's Theory

• Focus solely on cognitive changes without addressing emotional and social development.

• Lack of cultural consideration and rigid stage progression.

Psychosocial Development

• Development of personality and temperament established at birth.

• Three Basic Temperament Styles Identified:

  • Easy: Adaptable and positive mood.

  • Difficult: Intense reactions and mood swings.

  • Slow to Warm Up: Cautious in new situations.

• Tripartite blend: Many children exhibit mixed characteristics.

Kohlberg’s Stages of Moral Development

• Examination of moral reasoning in children through a series of stages:

  • Preconventional Stage (birth to age 9)

  • Decisions based on self-interest, weighing potential rewards or punishments.

  • Example: Heinz dilemma's moral reasoning varies with age.

  • Younger children might prioritize personal feelings, while older children place value on the sanctity of life and larger moral implications.

  • Developmental observations reveal a trend of moral reasoning sophistication with age.

Vygotsky’s Sociocultural Theory

• Emphasizes the importance of social and cultural context in cognitive development.

• Learning occurs best through guided participation, where adults model tasks while allowing children to assist and learn.

• Language Acquisition: Language plays a crucial role in cognitive complexity and shapes the way thoughts are structured.

• Example: Discussion of gendered language in different cultures and its effect on perceptions of social roles and stereotypes.

Feral Children

• The absence of social and cultural influences can severely affect development.

• Case Study: Genie Wiley, isolated for 13 years, lacked language acquisition due to extreme neglect.

  • Researchers examined the impact of severe isolation on language and overall development.

  • Ethical considerations and treatment of Genie raised significant concerns about the utilization of scientific experimentation.