Chapter 1: History, Theories, and research
strategies
I. Introduction to Developmental Science
● Definition: Developmental science studies human constancy and change throughout the
lifespan, influenced by various disciplines.
● Expansion of the Field: Developmental science grew due to scientific curiosity and the
practical needs of society to address issues at different life stages.
II. Basic Issues in Developmental Psychology
● Continuous vs. Discontinuous Development:
○ Continuous: Development is gradual, where skills improve over time, as seen in
information processing theories.
○ Discontinuous: Development occurs in distinct stages, where each stage has
unique characteristics, such as Piaget’s and Erikson’s stage theories.
● One Course of Development or Many?:
○ Universal Pathways: Some theories argue that everyone follows the same
developmental stages regardless of context.
○ Contextual Pathways: Other theories, like ecological systems theory, suggest
that development varies based on cultural and environmental contexts.
● Nature vs. Nurture:
○ Nature: Focuses on genetic inheritance and biological factors in development.
○ Nurture: Emphasizes the impact of environmental experiences and learning.
○ Theories vary in how much they attribute behavior and development to these
factors.
III. The Lifespan Perspective
● Characteristics of Lifespan Perspective:
○ Lifelong: Development is a continuous process from birth through old age.
○ Multidimensional and Multidirectional: Involves physical, cognitive, and social
domains, each contributing to a person's development in complex ways.
○ Plasticity: Development is flexible, allowing changes in response to different life
experiences, though flexibility tends to decrease with age.
○ Multiple Interacting Influences: Development is shaped by biological, historical,
and cultural contexts.
● Types of Influences:
○ Age-Graded Influences: Predictable influences based on age (e.g., learning to
walk).
, ○ History-Graded Influences: Influences unique to a historical period, like
technological advancements.
○ Non-Normative Influences: Individualized experiences, such as surviving a rare
disease.
IV. Scientific Beginnings
● Darwin’s Influence:
○ Darwin’s theory of evolution inspired the early scientific study of children,
focusing on adaptive behaviors.
● Normative Approach:
○ Developed by Hall and Gesell, this approach involved documenting typical
behaviors across age groups to understand development.
● Mental Testing Movement:
○ Binet and Simon’s intelligence testing sparked discussions about individual
differences, contributing to debates on nature vs. nurture.
V. Mid-Twentieth-Century Theories
● Psychoanalytic Theory:
○ Freud’s Psychosexual Theory: Personality development occurs through five
stages, focusing on conflicts between biological drives and social expectations.
○ Erikson’s Psychosocial Theory: Builds on Freud, proposing eight stages of
psychosocial conflicts that individuals face throughout life.
● Behaviorism and Social Learning Theory:
○ Focus on observable behavior through conditioning and modeling, emphasizing
environmental influence.
○ Key theorists: Watson, Skinner (operant conditioning), and Bandura (social
learning through observation).
● Piaget’s Cognitive-Developmental Theory:
○ Piaget proposed four stages where children actively construct knowedge as they
interact with their environment, from sensorimotor to formal operational stages.
VI. Recent Theoretical Perspectives
● Information Processing:
○ Describes the mind as a symbol-manipulating system, focusing on how
information is processed at different ages.
● Developmental Cognitive Neuroscience:
○ Examines how brain development affects cognitive processes, bridging
psychology and neuroscience.
● Ethology and Evolutionary Developmental Psychology:
○ Ethology focuses on the adaptive value of behaviors, while evolutionary
developmental psychology examines age-related changes that may have been
adaptive historically.
, ● Vygotsky’s Sociocultural Theory:
○ Stresses the importance of social interaction and cultural context in development.
● Ecological Systems Theory:
○ Proposed by Bronfenbrenner, this theory views development within nested
environmental systems, from immediate surroundings to broader societal
influences.
● Attachment Theory
○ Proposed by John Bowlby
VII. Comparing and Evaluating Theories
● Evaluation of Major Theories:
○ Theories are assessed based on their perspectives on the issues of continuity,
context, and nature vs. nurture.
● Cultural Considerations:
○ Contemporary theories increasingly recognize the role of culture in shaping
developmental pathways, suggesting that development cannot be separated from
cultural contexts.
VIII. Research Strategies in Developmental Psychology
● Common Research Methods:
○ Observational Methods:
■ Naturalistic Observation: Studying behaviors in their natural
environments.
■ Structured Observation: Observing behaviors in controlled settings.
○ Self-Reports:
■ Clinical Interviews: Open-ended discussions to gather detailed
information.
■ Structured Interviews/Questionnaires: Allow more standardized data
collection.
○ Case Studies: In-depth studies of individuals to understand unique
developmental experiences.
● Research Designs:
○ Correlational Studies: Examine relationships between variables without
implying causation.
○ Experimental Studies: Manipulate variables to test cause-and-effect
relationships.
○ Developmental Designs:
■ Longitudinal: Follows individuals over time to observe changes.
■ Cross-Sectional: Compares different age groups at a single time.
■ Sequential: Combines longitudinal and cross-sectional methods for a
comprehensive approach.
IX. Ethical Issues in Developmental Research
, ● Participant Rights:
○ Rights include protection from harm, informed consent, confidentiality, knowledge
of results, and access to beneficial treatments.
● Ethical Challenges:
○ Special considerations for vulnerable populations, such as children and
cognitively impaired older adults.
○ Ethical dilemmas include using deception and managing informed consent with
vulnerable participants.
Chapter 2: Genetic and Environmental Foundations
1. Genetic Foundations
● Genes and Inheritance:
○ Chromosomes and DNA:
■ Chromosomes are rod-like structures located in the cell nucleus and
composed of DNA (deoxyribonucleic acid), which encodes genetic
information.
■ Along the chromosome’s length are genes, which are segments of DNA
responsible for protein synthesis, ultimately guiding physical and
behavioral traits.
○ Types of Genes:
■ Protein-coding genes send instructions for making proteins essential for
bodily functions.
■ Regulator genes influence gene expression by modifying how
instructions from protein-coding genes are utilized, adjusting for
environmental impacts on gene behavior.
● Sex Cells and Meiosis:
○ The formation of gametes (sperm and ovum) involves meiosis, a cell division
process that reduces chromosome numbers by half. This ensures that upon
fertilization, the zygote has the complete set of chromosomes.
○ During meiosis, crossing over allows genes to shuffle, increasing genetic
diversity. The combination of genetic material from both parents during
fertilization results in a unique genetic makeup for the offspring.
● Determination of Sex:
○ Sex is determined by sex chromosomes: XX for females and XY for males.
○ Fraternal twins (dizygotic) occur when two separate eggs are fertilized by two
different sperm, while identical twins (monozygotic) form from the division of a
single fertilized egg, resulting in genetically identical siblings.
● Patterns of Gene Interactions: