100_4.1_Human Development.pdf

Human Development Overview (Lecture 4)

• Key Areas Covered:

  • Fetal development

  • Physical development

  • Cognitive development

  • Social development

  • Puberty, adulthood and aging

Fetal Development Process

• Fertilization:

  • A single sperm cell penetrates the egg, forming a fertilized cell.

• Location of Development:

  • If fertilized egg is stuck in the Fallopian tubes, surgery is needed.

Stages of Prenatal Development

1. Germinal Stage (first 2 weeks)

   • Zygote divides and differentiates into body structures.

2. Embryonic Stage (2-8 weeks)

   • The embryo attaches to the uterine wall, beginning to form the placenta.

3. Fetal Stage (8 weeks to birth)

   • Development of the fetus.

• Placenta Function:

  • Transfers nutrients, oxygen, and antibodies; filters out teratogens; prevents blood transfer between mother and fetus.

Teratogens and Their Effects

• Risks During Pregnancy:

  • German Measles (Rubella): Deafness, heart problems.

  • X-rays and Toxic Chemicals: Lower IQ, attention problems.

  • STDs: Intellectual disability, blindness.

  • Smoking: Miscarriage, premature birth, underweight babies.

  • Alcohol Consumption: Birth defects, fetal alcohol syndrome (FAS).

  • Drugs: Impaired cognitive and language abilities.

Developmental Stages

• Infancy to Childhood:

  • Span: Birth to teenage years.

  • Physical, cognitive, and social growth occurs.

Reflexes in Infants

• Survival Reflexes:

  • Rooting Reflex: Turns head towards touch.

  • Sucking Reflex: Sucks on objects touching the roof of the mouth.

  • Moro Reflex: Startle reaction.

Brain Development

• Brain Cells: Present before birth, developing neural networks.

• Development Timeline:

  • 3 to 6 years: Frontal lobe (rational planning) develops.

  • 6 to puberty: Association areas develop.

Motor Development Sequence

• Sequence of Motor Skills:

  • Rolling over → sitting unsupported → crawling → walking.

  • Sequence is largely unaffected by experience.

Stages of Cognitive Development (Piaget)

1. Sensorimotor Stage (0-2 years):

   • Learning through senses and actions.

   • Key Developments:

     • Object permanence (develops around 8 months).

     • Stranger anxiety (develops around 7-8 months).

2. Preoperational Stage (2-6/7 years):

   • Memory and language develop.

   • Characteristics:

     • Egocentrism, lack of conservation understanding.

3. Concrete Operational Stage (7-11 years):

   • Logical thinking develops.

   • Understanding of conservation, comparison, and categorization.

4. Formal Operational Stage (12 and up):

   • Abstract and systematic reasoning develops.