Lifespan Development: Foundations and Prenatal Development

Chapter 1: Introduction to Lifespan Development

Overview of Lifespan Development

Lifespan development is the scientific study of growth, change, and stability throughout the human life span. It encompasses physical, cognitive, and psychosocial domains, examining how individuals evolve from conception to old age.

• Physical Development: Involves changes in the body, brain, nervous system, food intake, and sleep patterns.

• Cognitive Development: Encompasses learning, memory, problem-solving, and intelligence.

• Personality & Social Development: Focuses on traits, social interaction, and relationships.

Influences on Development

• History-Graded Influences: Events unique to a particular historical era (e.g., COVID-19 pandemic).

• Age-Graded Influences: Biological and environmental influences similar for individuals in a particular age group (e.g., puberty, retirement).

• Sociocultural-Graded Influences: Social and cultural factors such as ethnicity, social class, and subcultural membership.

• Non-Normative Life Events: Unusual occurrences that have a major impact on an individual's life (e.g., rare accidents).

Piaget’s Cognitive Processes

• Schema: A mental framework for organizing information.

• Assimilation: Incorporating new experiences into existing schemas.

• Accommodation: Modifying existing schemas to fit new information.

Maslow’s Hierarchy of Needs

• Physiological → safety → social → esteem → self-actualization.

Bronfenbrenner’s Ecological Systems Theory

• Microsystem: Immediate environment (family, school).

• Exosystem: Indirect environment (parent’s workplace).

• Macrosystem: Cultural context.

• Chronosystem: Time-based dimension (life transitions).

Research Methods in Developmental Psychology

• Correlational Studies: Examine relationships between variables.

• Naturalistic Observation: Observing behavior in natural settings.

• Case Studies: In-depth analysis of individuals or groups.

• Surveys and Experiments: Collecting data through questionnaires or controlled studies.

Chapter 2: The Start of Life (Prenatal Development)

Genetics and Heredity

Genetics is the study of heredity and the variation of inherited characteristics. Human beings have approximately 25,000–30,000 genes, which are segments of DNA that code for proteins and determine traits.

• Genotype: The genetic makeup of an individual.

• Phenotype: The observable characteristics resulting from the interaction of genotype and environment.

Genetic Disorders

• Down Syndrome: Caused by an extra 21st chromosome.

• Sickle Cell Anemia: A disorder affecting hemoglobin in red blood cells.

• Duchenne Muscular Dystrophy: A genetic disorder characterized by progressive muscle degeneration.

Genetic Counseling and Prenatal Testing

• Genetic Counseling: Involves family history analysis, genetic testing, and risk assessment for inherited disorders.

• Prenatal Testing: Includes ultrasound imaging and amniocentesis to detect developmental abnormalities.

Stages of Prenatal Development

• Germinal Stage (0–2 weeks): Zygote divides and implants in the uterine wall.

• Embryonic Stage (2–8 weeks): Major organs and structures begin to form.

• Fetal Stage (8 weeks–birth): Continued growth and development of the body and brain.

Risks to Prenatal Development

• Teratogens: Environmental agents (e.g., drugs, alcohol, poor health) that can cause harm to the developing fetus.

• Infertility: Difficulty in conceiving children; affects approximately 6% of married women aged 15–44 in the U.S.

• Abortion: Approximately 73 million abortions occur worldwide each year.

Chapter 4: Physical Development in Infancy

Neural and Brain Development

• Neurons: Nerve cells that transmit information. Structure: dendrites → cell body → axon → myelin sheath (increases speed of transmission).

• Multiple Sclerosis (MS): A disease where myelin is damaged, slowing neural transmission.

• Neurotransmitters: Chemical messengers such as dopamine and serotonin.

Synaptic Connections and Brain Plasticity

• Synaptic Connections: Increase with experience; more connections lead to better processing and learning.

• Plasticity: The brain's ability to adapt and form new connections, especially in early life.

Brain Hemispheres and Cerebral Cortex

• Left Hemisphere: Associated with reading, writing, and math.

• Right Hemisphere: Associated with spatial abilities and facial recognition.

• Corpus Callosum: Connects the two hemispheres, allowing communication between them.

• Cerebral Cortex: Divided into lobes with specialized functions:

  • Frontal: Thinking, language, morality, and planning.

  • Parietal: Sensation and spatial processing.

  • Occipital: Vision.

  • Temporal: Hearing.

  • Cerebellum: Balance and coordination.

  • Hypothalamus: Eating and other regulatory functions.

Infant Mortality Risks

• SUID: Sudden Unexpected Infant Death, often due to suffocation.

• SIDS: Sudden Infant Death Syndrome, responsible for approximately 1,250 infant deaths annually in the U.S.