Comprehensive Guide to AP Psychology Unit 3: Developmental & Learning Sciences

Major Themes in Developmental Psychology

Developmental Theories & Debates

Developmental Psychology examines physiological, cognitive, and social changes across the lifespan. It is framed by three major continuously debated issues:

1. Nature vs. Nurture: How does our genetic inheritance (nature) interact with our experiences (nurture) to feel our development?

   • Current View: Interactionist—genes predispose us to certain traits, but the environment determines how they are expressed (epigenetics).

2. Continuity vs. Stages (Discontinuity):

   • Continuity: Development is a gradual, continuous process (like riding an escalator). Researchers who emphasize learning and experience often see development this way.
   • Stages: Development occurs in distinct steps or stages (like climbing a ladder). Theories by Piaget (cognitive), Kohlberg (moral), and Erikson (psychosocial) are stage theories.

3. Stability vs. Change: Do our early personality traits persist through life, or do we become different persons as we age?

   • Findings: Temperament tends to be stable; social attitudes are more likely to change.

Research Methods in Development

Physical Development Across the Lifespan

Prenatal Development

Development begins at conception and progresses through three clear stages:

1. Zygote (0–2 weeks): Fertilized egg; rapid cell division; enters a 2-week period of rapid cell division and develops into an embryo.
2. Embryo (2–8 weeks): The developing human organism from about 2 weeks after fertilization through the second month. Organs begin to form.
3. Fetus (9 weeks–birth): The developing human organism from 9 weeks after conception to birth.

Teratogens are agents (chemicals, viruses) that can reach the embryo or fetus during prenatal development and cause harm.

• Fetal Alcohol Syndrome (FAS): Physical and cognitive abnormalities in children caused by a pregnant woman's heavy drinking.

Infant & Child Development

Reflexes: Infants are born with innate, survival-based reflexes.

• Rooting: Turning head when cheek is touched to find a nipple.
• Moro (Startle): Throwing arms out when startled.
• Babinski: Fanning toes when the sole of the foot is stroked.

Brain Development:

• Maturation: Biological growth processes that enable orderly changes in behavior, relatively uninfluenced by experience.
• Pruning: The process where unused neural connections decay and disappear, while used connections are strengthened ("use it or lose it").
• Critical Period: An optimal period early in the life of an organism when exposure to certain stimuli or experiences produces normal development (e.g., for language or vision).

Adolescence

• Puberty: The period of sexual maturation, during which a person becomes capable of reproducing.
• Primary Sex Characteristics: Body structures (ovaries, testes, and external genitalia) that make sexual reproduction possible.
• Secondary Sex Characteristics: Non-reproductive sexual traits (breasts, hips, male voice quality, body hair).
• Brain Development: The Limbic System (emotions) develops faster than the Frontal Lobes (judgment/control), often explaining risky adolescent behavior.

Adulthood & Aging

• Early Adulthood: Peak physical performance.
• Middle Adulthood:
  • Menopause: Cessation of menstruation in women.
• Late Adulthood:
  • Sensory abilities (vision, smell, hearing) decline.
  • Telomeres (tips of chromosomes) wear down, accelerating aging.

Cognitive Development

Jean Piaget’s Stage Theory

Piaget believed children actively construct their understanding of the world through:

• Schemas: Concepts or frameworks that organize and interpret information.
• Assimilation: Interpreting new experiences in terms of existing schemas (e.g., calling a zebra a "horse").
• Accommodation: Adapting current schemas to incorporate new information (e.g., realizing a zebra is different from a horse).

1. Sensorimotor Stage (Birth–2 Years)

• Experiencing the world through senses and actions.
• Key Milestone: Object Permanence (awareness that things continue to exist even when not perceived), typically develops around 8 months.

2. Preoperational Stage (2–7 Years)

• Representing things with words and images (symbolic thinking) but lacking logical reasoning.
• Egocentrism: Difficulty taking another’s point of view.
• Animism: Belief that inanimate objects have feelings.
• Theory of Mind: People's ideas about their own and others' mental states (starts developing here).

3. Concrete Operational Stage (7–11 Years)

• Thinking logically about concrete events.
• Conservation: Understanding that mass, volume, and number remain the same despite changes in forms (e.g., pouring liquid into a tall, thin glass does not change the amount).
• Reversibility: The ability to mentally reverse an operation.

4. Formal Operational Stage (12+ Years)

• Abstract reasoning and hypothetical thinking.

Vygotsky’s Sociocultural Theory

Unlike Piaget, Lev Vygotsky emphasized how culture and social interaction guide cognitive development.

• Zone of Proximal Development (ZPD): The gap between what a child can do alone and what they can do with help.
• Scaffolding: Temporary support that is tailored to a learner’s needs and abilities and aimed at helping the learner master the next task in a given learning process.

Cognitive Changes in Adulthood

• Fluid Intelligence: Our ability to reason speedily and abstractly; tends to decrease during late adulthood.
• Crystallized Intelligence: Our accumulated knowledge and verbal skills; tends to increase with age.

Social & Emotional Development

Attachment Theory

Attachment is an emotional tie with another person.

1. Harry Harlow’s Monkeys: Demonstrated that attachment is based on contact comfort (warmth/softness) rather than nourishment. Infant monkeys preferred the cloth mother over the wire mother with food.

2. Konrad Lorenz & Imprinting: The process by which certain animals form strong attachments during an early-life critical period (e.g., ducks following the first moving object).

3. Mary Ainsworth’s Strange Situation: A procedure to study attachment styles by observing infants' reactions to the mother leaving and returning.

   • Secure Attachment: Distress when mother leaves, seeking contact when she returns. Associated with sensitive, responsive parenting.
   • Insecure-Avoidant: Little distress when mom leaves, ignores her upon return.
   • Insecure-Anxious/Ambivalent: Intense distress when leaving, resists contact or is angry upon return.

Parenting Styles (Diana Baumrind)

Erikson’s Psychosocial Stages

Erik Erikson proposed that each stage of life has its own psychosocial task, a crisis that needs resolution.

1. Trust vs. Mistrust (Infancy): Needs met comfortably = trust.
2. Autonomy vs. Shame/Doubt (Toddler): Exercise will/do things for self.
3. Initiative vs. Guilt (Preschool): Initiate tasks and carry out plans.
4. Industry vs. Inferiority (School Age): Joy in applying oneself to tasks.
5. Identity vs. Role Confusion (Adolescence): Refining a sense of self. Key crisis for teenagers.
6. Intimacy vs. Isolation (Young Adult): Forming close relationships.
7. Generativity vs. Stagnation (Middle Adult): Contributing to the world/family.
8. Integrity vs. Despair (Late Adult): Reflection on life.

Moral Development

Lawrence Kohlberg’s Levels of Moral Thinking

Kohlberg assessed moral reasoning by posing hypothetical moral dilemmas (e.g., the Heinz Dilemma).

1. Preconventional Morality (Before age 9): Self-interest; obey rules to avoid punishment or gain concrete rewards.
2. Conventional Morality (Early adolescence): Uphold laws and rules to gain social approval or maintain social order.
3. Postconventional Morality (Adolescence and beyond): Actions reflect belief in basic rights and self-defined ethical principles.

Carol Gilligan’s Critique: Criticized Kohlberg for studying only boys. She argued women focus more on caring and relationships ethics rather than abstract justice.

Learning Theories: Classical Conditioning

Learning is a relatively permanent change in an organism's behavior due to experience.

Pavlov & The Basics

Classical Conditioning is a type of learning where an organism comes to associate stimuli. (Ivan Pavlov).

• Unconditioned Stimulus (US): A stimulus that naturally triggers a response (e.g., Food).
• Unconditioned Response (UR): An unlearned, natural response to the US (e.g., Salivation).
• Neutral Stimulus (NS): A stimulus that elicits no response before conditioning (e.g., Bell).
• Conditioned Stimulus (CS): An originally neutral stimulus that, after association with a US, triggers a response (e.g., Bell becomes CS).
• Conditioned Response (CR): The learned response to a previously neutral CS (e.g., Salivation to the bell).

Key Principles

• Acquisition: The initial stage where the link is established (NS + US).
• Extinction: The diminishing of a CR; occurs when the US does not follow the CS.
• Spontaneous Recovery: The reappearance, after a pause, of an extinguished CR.
• Generalization: The tendency to respond to stimuli similar to the CS (e.g., fearing all furry white objects, not just the rat—seen in the Little Albert Experiment by Watson).
• Discrimination: The learned ability to distinguish between a CS and other irrelevant stimuli.

Biological Constraints

• Taste Aversion (Garcia Effect): John Garcia showed that rats could learn to avoid a taste (CS) if it induced nausea (UR) hours later. This defies the idea that conditioning requires immediate timing, showing biological predisposition to associate taste with sickness for survival.

Learning Theories: Operant Conditioning

Operant Conditioning creates an association between behavior and consequence (reward or punishment). Associated with B.F. Skinner and Edward Thorndike (Law of Effect).

Reinforcement vs. Punishment

Reinforcement INCREASES behavior.

• Positive Reinforcement: Adding a desirable stimulus (e.g., giving a dog a treat).
• Negative Reinforcement: Removing an aversive stimulus (e.g., fastening a seatbelt to stop the annoying beeping).

Punishment DECREASES behavior.

• Positive Punishment: Adding an aversive stimulus (e.g., spanking, giving a speeding ticket).
• Negative Punishment: Removing a desirable stimulus (e.g., taking away the phone, time-out).

Schedules of Reinforcement

How often is the behavior reinforced? This affects how fast learning happens and how resistant it is to extinction.

1. Fixed-Ratio (FR): Reinforces a response only after a specified number of responses (e.g., Buy 10 coffees, get 1 free). High response rate.
2. Variable-Ratio (VR): Reinforces a response after an unpredictable number of responses (e.g., Slot machines). Most resistant to extinction.
3. Fixed-Interval (FI): Reinforces a response only after a specified time has elapsed (e.g., Paycheck every 2 weeks). Choppy response pattern (scalloped).
4. Variable-Interval (VI): Reinforces a response at unpredictable time intervals (e.g., Fishing, checking email). Slow, steady responding.

Social & Cognitive Factors in Learning

Observational Learning

Learning by observing others (Social Learning Theory).

• Albert Bandura & The Bobo Doll Experiment: Children observed adults hitting a doll and mimicked the aggression.
• Modeling: The process of observing and imitating a specific behavior.
• Mirror Neurons: Frontal lobe neurons that fire when performing certain actions or when observing another doing so. The brain's mirroring of another's action may enable imitation and empathy.
• Prosocial Behavior: Positive, constructive, helpful behavior (opposite of antisocial behavior).

Cognitive Learning

• Latent Learning (Tolman): Learning that occurs but is not apparent until there is an incentive to demonstrate it (e.g., rats creating a "cognitive map" of a maze without reward).
• Insight Learning (Köhler): A sudden realization of a problem's solution (the "Aha!" moment), practiced by chimps reaching for bananas.
• Learned Helplessness (Seligman): The hopelessness and passive resignation an animal or human learns when unable to avoid repeated aversive events.
• Locus of Control (Rotter):
  • Internal: You control your own fate.
  • External: Chance or outside forces determine your fate.

Common Mistakes & Pitfalls

1. Negative Reinforcement vs. Punishment: This is the #1 mistake. Remember: Reinforcement always makes a behavior happen MORE. Punishment makes it happen LESS. Negative Reinforcement is "relief" (taking away pain), not inflicting pain.
2. Imprinting vs. Attachment: Imprinting happens mainly in birds and is irreversible during a critical period. Humans form attachment, which is flexible and develops over months.
3. Fluid vs. Crystallized Intelligence: Don't swap them. Fluid flows (speed, abstract) and dries up with age. Crystallized is like a crystal (solid, accumulated knowledge) that grows.
4. Authoritative vs. Authoritarian: "Authoritarian" is like a libraryan (quiet, strict, rules). "Authoritative" is supportive (give and take).
5. Role Confusion: Often confused with "Identity Crisis". In Erikson's stage, if you don't find your Identity, you fall into Role Confusion (not knowing where you fit in society).
6. Ratio vs. Interval: Ratio = Number (counting responses). Interval = Time (watching the clock). If the reward depends on you doing it a bunch of times, it's Ratio. If it depends on waiting five minutes, it's Interval.