Human Development
Why
The goal of developmental Psychology: Understand human struggles/triumphs
Divide into 3 major categories: physical, cognitive, and socioemotional.
Physical growth of children: Maturation
Side.. Note…
text
“Physical changes continue, but not necessarily in a positive or growth direction. Some people, for example, experience vision loss as they age”
Changes in memory, problem solving, decision making, language, and intelligence all fall under the umbrella of cognitive development.
Socioemotional development refers to social behaviors, emotions, and changes people experience
3 Major themes: three major themes: nature and nurture, stages and continuity, and stability and change.
Nature/Nurture
degree to which heredity (nature) and environment (nurture) influence behavior and development
Stages or Continuity?
Critical period of development, experiences can lead to new behavior patterns and “irreversible changes”
Stability and Change
degree to which characteristics change across the life span. For example, how stable is personality over time and across situations?
The 3 Designs…
longitudinal—single group at different points in time; cross-sectional—groups of people at different ages at a single point in time; cross-sequential—groups of people at different ages at different points in time
the cross-sectional method, we can examine people of different ages at a given point in time.
However, this approach doesn’t tell us whether differences across age groups result from actual developmental changes or from common experiences within groups, a phenomenon known as the cohort effect
by using the longitudinal method, which follows one group of individuals over a period of time.
The cross-sequential method, also used by developmental psychologists, is a mixture of the longitudinal and cross-sectional methods.
Chromo
A sperm united with an egg to form a zygote
A chromosome contains one molecule of deoxyribonucleic acid (DNA)
Identical or monozygotic twins develop when one egg is fertilized by one sperm and then splits, forming two separate zygotes with identical sets of 46 chromosomes.
dizygotic twins, on the other hand, result when two eggs are fertilized by two different sperm, leading to two distinct zygotes.
The field that examines the processes involved in the development of phenotypes is known as epigenetics,
(XXY as opposed to the typical XY). Common features include tall stature, breast development, infertility, and underdeveloped sexual organs and secondary sex characteristics
is the schema [SKEE-muh], a collection of ideas that serves as a building block of understanding.
innate need to maintain cognitive equilibrium,
Sensorimotor Stage (Birth–2 years)
Definition: Infants learn about the world through sensory input and motor activity.
Key Milestone: Object permanence — understanding that objects and people still exist even when out of sight.
Example: A baby who has achieved object permanence will search for a hidden toy.
Preoperational Stage (Ages 2–7)
Definition: Children use language and symbolic thinking to explore their world.
Key Features:
Egocentrism: Difficulty seeing the world from others’ perspectives.
Theory of Mind: Developing understanding that others have their own thoughts and feelings.
Lack of operations: Cannot yet perform logical reasoning like reversibility.
Errors in conservation: Misunderstanding that volume or mass stays the same when appearance changes.
Concrete Operational Stage (Ages 7–11)
Definition: Children begin using logical thinking but only for concrete (real, observable) situations.
Key Features:
Understand conservation and reversibility.
Less egocentric.
Struggle with abstract or hypothetical questions.
Formal Operational Stage (Begins around age 11+)
Definition: Ability to think abstractly, hypothetically, and logically in complex ways develops.
Example: Can reason through imagined scenarios and consider multiple outcomes.
Additional Notes
Conservation Tasks (Figure 8.3): Used to test if children understand that properties like volume/mass remain constant despite changes in form.
"Little Scientist" Insight: Even babies may use basic logical reasoning (like process of elimination) earlier than Piaget originally proposed.
What is the Third Eye Task?
Children are asked:
"If you could have a third eye anywhere on your body, where would you put it and why?"
Younger children (typically in the Concrete Operational Stage) tend to answer literally—placing the eye on their forehead because “that’s where eyes go.”
Older children or those in the Formal Operational Stage (age 11+) often give more imaginative, problem-solving answers, like putting the eye on their hand “so I can see around corners,” showing abstract thinking and innovation.
Dis
Erikson’s theory of development addresses this important issue of identity formation
puberty to the twenties is the stage of ego identity versus role confusion,
they may enter this stage with distrust toward others, and feelings of shame, guilt, and inadequacy