AP Psychology Unit 3: Developmental Psychology and Learning Comprehensive Notes

Introduction to Unit Three and Developmental Psychology

Unit Scope: Unit three of AP Psychology covers the expansive fields of Developmental Psychology and Learning. This unit is significant for academic assessment, accounting for $15-25\%$ of the AP exam.
Definition of Developmental Psychology: This field focuses on the study of how humans change over time. While development occurs throughout the lifespan, developmental psychologists concentrate most heavily on childhood, as this is the period where the most rapid and significant changes occur.

Major Debates in Developmental Psychology

Psychologists evaluate human growth through three primary complex debates:

Nature versus Nurture: This debate questions whether development is driven by biology (genes) or environment. The consensus in the field is that the answer is "both." Genes (nature) establish the foundation of an individual, while the environment (nurture) determines how that foundation is shaped and developed.
Stability versus Change: This debate explores whether individuals remain the same person throughout their lives or undergo drastic changes. The conclusion is often "both."
- Stability: Certain traits, such as a temperamental personality (e.g., being consistently shy or outgoing), tend to remain stable throughout life.
- Change: Social attitudes and coping skills frequently undergo significant transformations over time.
Continuity versus Stages: This debate centers on whether human development is a gradual, smooth process (continuity) or occurs through distinct processes and jumps (stages). Psychologists debate which specific traits follow a smooth trajectory versus a step-like progression.

Research Designs in Developmental Psychology

Research in this field is primarily conducted using two specialized designs:

Cross-sectional Study: Psychologists compare different age groups (e.g., comparing a $5$ year old to a $10$ year old) at a single point in time.
- Limitation: Differences observed might be generational (cohort effects) rather than developmental, as the subjects are different individuals.
Longitudinal Study: This design follows the same group of individuals over an extended period.
- Advantages: It is considered the most reliable method for tracking changes over time.
- Disadvantages: It is extremely time-consuming, and participants may lose interest or drop out over time.

Prenatal Development and Environmental Influences

Prenatal Definition: This period refers to the time before a child is born.
Teratogens: These are harmful substances that can damage the development of a fetus. Examples include drugs and alcohol.
Illness: Maternal illnesses during pregnancy, such as the flu or COVID, can negatively impact development.
Additional Factors: Prenatal development is also affected by genetic mutations, hormones, and environmental factors such as the woman's nutrition, exposure to pollution, or high levels of stress.

Infancy and Childhood: Physical and Motor Development

Universal Order: Development generally follows a specific sequence but occurs at different times for every child.
Infant Reflexes: The earliest signs of development are reflexes. One specific example is the rooting reflex, where touching an infant's cheek causes them to turn their head and suck.
Motor Development: Occurs once initial reflexes fade.
- Gross Motor Skills: Larger movements such as crawling and walking.
- Fine Motor Skills: Precise movements such as grasping small objects or drawing.
Perception: Develops as a safety mechanism once children can walk. The Visual Cliff Experiment demonstrated this; infants hesitated to move across a man-made drop-off point, showing early depth perception.
Critical Windows: Certain abilities, including language and social attachment, must develop within specific time windows for optimal results.
Imprinting: In some nonhuman animals, attachment is formed with the first caregiver-like figure they see.

Adolescence and Puberty

Puberty Characteristics: This stage involves a visible growth spurt in both men and women.
Brain Development: The limbic system develops faster during this period, leading to increased emotional intensity, higher risk-taking behaviors, and the formation of a personal identity.
Sexual Maturation:
- Women: Development of breasts, body hair, and the first menstrual period, termed menarche (transcript spelling).
- Men: Deepening of the voice, body hair, and the first ejaculation, termed spermarche (transcript spelling).

Adulthood and Aging

Physical Peak: Humans typically peak in physical ability around the age of $28$ .
Physical Decay: After the peak, abilities decline slowly until death. This includes declines in:
  - Reproductive ability.
  - Mobility and flexibility.
  - Reaction time.
  - Vision and hearing.
Cognitive Gains: While physical abilities decline, individuals often become more knowledgeable through life experience.

Sex, Gender, and Sexual Orientation

Sex: Refers to the biological differences between being a male or female.
Gender: Refers to the socialized norms and expectations society has for males and females.
Gender Socialization: Societal responses to behaviors (e.g., telling someone to "man up" vs. offering comfort) shape the groups of behavior considered "normal" for each gender.
Gender Identity: This is how a person personally identifies (male, female, both, neither, etc.). It can be distinct from their biological sex.
Sexual Orientation: This refers to personal attraction. Categories include:
  - Heterosexual: Attracted to the opposite sex.
  - Bisexual: Attracted to both sexes.
  - Homosexual: Attracted to the same sex.
  - Asexual: Attracted to no one.

Piaget’s Theory of Cognitive Development

Jean Piaget argued that children fit new information into schemas through two processes: accommodation and assimilation. He proposed four distinct stages:

Sensorimotor Stage ( $0-2$ years): Focuses on the development of object permanence, the understanding that objects exist even when they are not visible.
Preoperational Stage ( $2-7$ years): Includes pretend play and the development of theory of mind. Children are egocentrism (unable to see things from others' perspectives) and cannot perform tasks involving conservation or reversibility.
Concrete Operational Stage ( $7-11$ years): Children begin to think logically about concrete events and understand conservation, though they still struggle with systematic thinking.
Formal Operational Stage ( $12$ years and up): Adolescents begin to think abstractly, use hypothetical and deductive reasoning, and solve problems systematically. Piaget noted that not all people reach this level of reasoning.

Vygotsky’s Zone of Proximal Development and Intelligence

Lebvigotzky’s (transcript spelling) Zone of Proximal Development (ZPD): Represented by a series of concentric circles:
  - Inner Circle: Current understanding/tasks a child can do unassisted.
  - Middle Circle (ZPD): Tasks a child can achieve with assistance, known as scaffolding.
  - Outer Circle: Knowledge is currently out of reach for the child.
Intelligence Types:
- Fluid Intelligence: The ability to think on one's feet, solve new problems, and adapt. This tends to decline with age.
- Crystallized Intelligence: The accumulated knowledge and skills built up over time. This generally remains stable or increases with age.
Dementia: A mental disorder involving a significant decline in memory and cognitive ability.

Language Development

Components of Language:
  - Phonemes: The smallest unit of sound that can change a word's meaning. English has approximately $44$ .
  - Morphemes: The smallest unit of meaning (e.g., "unhappy" contains "un" meaning "not" and "happy" meaning the feeling).
  - Semantics: The meaning behind words, phrases, and sentences.
  - Grammar: The system of rules governing language.
  - Syntax: The specific order of words.
Stages of Language Acquisition:
  1. Cooing: Simple vowel sounds (e.g., "oh," "ah").
  2. Babbling: Consonant-vowel combinations (e.g., "ba," "da").
  3. One-word stage: Speaking single, isolated words.
  4. Telegraphic speech: Two-word combinations (e.g., "want cookie").
Overgeneralization: A common error where children apply grammar rules too broadly (e.g., saying "I goed" or "two foots").

Social and Ecological Systems

Bronfenbrenner’s Ecological Systems Theory: Consists of five layers around a person:
  - Microsystem: Direct interactions (e.g., family, peers).
  - Mesosystem: How the microsystem groups interact (e.g., parent-teacher interaction).
  - Exosystem: Indirect influences (e.g., a parent's workplace).
  - Macrosystem: The broader culture.
  - Chronosystem: Changes over time due to life stages and historical events.
Parenting Styles:
  - Authoritarian: Enforce strict rules and allow little flexibility.
  - Authoritative: Set rules but respond to needs and communicate expectations clearly (generally considered most effective).
  - Permissive: Few rules with high levels of freedom.

Attachment and Social Behavior

Harry Harlow's Monkey Study: Proved that "contact comfort" is more important than nourishment for forming attachment, as monkeys preferred a cloth mother over a wire mother with food.
Mary Ainsworth’s Strange Situation: Classified infant attachment into four types:
  - Secure: Explore freely, upset when caregiver leaves, easily comforted upon return.
  - Insecure Avoidant: Indifferent to caregiver's presence or absence.
  - Insecure Anxious: Clingy and remains distressed even after return.
  - Disorganized: Show inconsistent or odd behaviors.
Adolescent Egocentrism: The belief that everyone is watching them and that their experiences are unique.
Social Clock: The culturally determined schedule for when major life milestones (e.g., marriage, children) "should" occur.

Erik Erikson’s Eight Stages of Psychosocial Development

Trust vs. Mistrust: Infants learn if the world is safe or fearful.
Autonomy vs. Shame and Doubt: Toddlers develop independence or doubt their abilities.
Initiative vs. Guilt: Young children try new activities or feel guilty for asserting themselves.
Industry vs. Inferiority: School-age children build competence or feel incapable.
Identity vs. Role Confusion: Teens form a clear identity or remain unsure of their values.
Intimacy vs. Isolation: Young adults form committed relationships or struggle to connect.
Generativity vs. Stagnation: Adults contribute to society or feel unproductive.
Integrity vs. Despair: Older adults reflect on life with satisfaction or regret.

Adverse Childhood Experiences (ACEs): Early traumas that affect relationships and life outcomes.

Classical Conditioning

Classical conditioning involves training automatic, involuntary responses.

Ivan Pavlov’s Dog Experiment:
- Before Conditioning: Food (Unconditioned Stimulus / UCS) triggers salivation (Unconditioned Response / UCR). The bell is a Neutral Stimulus (NS).
- During/After: The bell is paired with food. Eventually, the bell alone triggers salivation. The bell becomes the Conditioned Stimulus (CS) and salivation becomes the Conditioned Response (CR).
Key Principles:
  - Order: The CS must come immediately before the UCS.
  - Extinction: The CR fades if the CS is no longer paired with the UCS.
  - Spontaneous Recovery: The sudden reappearance of an extinct CR.
  - Habituation: Diminished response to a stimulus repeated without meaningful outcome.
  - Generalization: Responding to stimuli similar to the CS.
  - Discrimination: Distinguishing between different stimuli.
  - Taste Aversion: A unique "one-trial learning" association between food and illness based on biological preparedness.

Operant Conditioning

Operant conditioning involves training voluntary behaviors based on consequences.

Thorndyke’s (transcript spelling) Law of Effect: Behaviors with good outcomes are repeated; behaviors with bad outcomes are avoided.
BF Skinner’s Box: Used "shaping" (rewarding incremental steps) to teach a pigeon to peck a disc for food.
Reinforcement and Punishment ( $2 \times 2$ Table):
  - Positive Reinforcement: Adding something good to increase behavior.
  - Negative Reinforcement: Removing something bad to increase behavior.
  - Positive Punishment: Adding something bad to decrease behavior.
  - Negative Punishment: Removing something good to decrease behavior.
Reinforcement Schedules:
  - Fixed Ratio: Reward after a set number of behaviors.
  - Fixed Interval: Reward after a set amount of time.
  - Variable Ratio: Reward after a random number of behaviors (highest performance/steepest slope).
  - Variable Interval: Reward after random amounts of time.
Key Terms:
- Learned Helplessness: Avoiding action after repeated unavoidable failures.
- Superstitious Behavior: Accidental reinforcement of unrelated behaviors.

Cognitive and Social Learning Theories

Albert Bandura’s Social Learning Theory: Demonstrated through the Bobo Doll Experiment. Children watched an adult beat a doll and imitated the behavior without being directly reinforced or punished. Learning can happen strictly through observation.
Mirror Neurons: Neurological components that make imitation possible.
Insight Learning: An "Aha!" moment where a solution is realized instantly. (Example: Chimps stacking boxes to reach bananas).
Latent Learning: Learning that occurs without reinforcement and is not demonstrated until a reward is offered. Tolman showed this with rats developing a cognitive map of a maze even without an initial incentive.