An infant stops crying when they see their father walk into the room, even if he was hidden behind a door seconds ago.
Object Permanence
A driver stops at a red light in the middle of the desert with no cameras or police around simply because "it is the law."
Conventional Morality (Stage 4: Law and Order)
A child calls a zebra a "horse" because they have only ever seen four-legged animals with manes on a farm.
Assimilation
When a mother returns to the room, her toddler runs to her, gives her a hug, and then happily returns to playing with the blocks.
Secure Attachment
A child’s behavior is analyzed not just by their personality, but by their home life, their school, their parents' workplace, and the national economy.
Ecological Systems Theory
A 10-year-old is obsessed with collecting baseball cards, sorting them by team, batting average, and city.
Concrete Operational Stage
A toddler shares her crackers with a crying peer only because her teacher promised her a "gold star" sticker for doing so.
Preconventional Morality (Stage 2: Individualism and Exchange)
A student uses a "cheat sheet" of formulas for a week, then a list of hints the next week, until they can solve the physics problems entirely on their own.
Scaffolding
A father tells his daughter, "You will study medicine because I am paying for it, and there will be no further discussion."
Authoritarian Parenting
A 40-year-old man feels a sense of "emptiness" because he has focused only on his own wealth and hasn't mentored anyone or contributed to the next generation.
Stagnation (vs. Generativity)
A 4-year-old insists that his stuffed bear is "sad" because it was left home alone during a family vacation.
Animism (within the Preoperational Stage)
A protestor blocks a highway to demand changes to a law they believe violates the fundamental human right to clean water.
Postconventional Morality (Stage 6: Universal Ethical Principles)
A toddler talks out loud to himself while building a block tower, saying "Put the big one on the bottom, now the little one," to help manage the task.
Private Speech (or Self-Directed Speech)
A baby monkey in an isolation chamber ignores a wire mesh "mother" that provides milk, instead clinging to a foam-covered "mother" that provides no food.
Contact Comfort
A critic argues that a specific IQ test is invalid because it uses vocabulary that only children from wealthy, urban neighborhoods would recognize.
Cultural Bias
During a chemistry lab, a 16-year-old creates a list of all possible chemical combinations before starting the experiment to see which might result in a color change.
Hypothetical-Deductive Reasoning (Formal Operational Stage)
A person decides not to report a coworker’s minor theft because they believe maintaining the harmony of the office "family" is more important than the company's handbook.
Ethics of Care (or Gilligan’s Care Perspective)
A teacher notices a student can't solve long division alone but can do it perfectly if the teacher simply underlines the "remainder" step for them.
Zone of Proximal Development (ZPD)
A child is highly distressed when their parent leaves but, upon the parent's return, alternatingly clings to them and hits them in frustration.
Anxious-Ambivalent (Resistant) Attachment
An 80-year-old woman spends her days writing her memoirs, feeling a deep sense of peace that her life, despite its hardships, was well-spent.
Ego Integrity
A researcher observes that infants in a specific remote tribe begin walking at 10 months without any "tummy time" or parental prodding, suggesting a genetic blueprint.
Maturation (or Maturation Theory)
A 15-year-old joins the "Goth" subculture for three months, then switches to being a "Student Athlete," trying to see which peer group feels most authentic.
Identity vs. Role Confusion
An adult finds it nearly impossible to learn the native "clicks" of a Xhosa speaker because they were never exposed to those phonemes during the first few years of life.
Critical Period (in Language Acquisition)
A child grows up to be highly self-reliant and socially capable because their parents set firm curfews but were always willing to negotiate them for special occasions.
Authoritative Parenting
A scientist argues that a child's aggressive behavior isn't learned from TV, but is an evolutionary "short-cut" for survival passed down through their DNA.
Ethology (or Evolutionary Psychology)