AP Psychology Unit 1: Scientific Foundations of Psychology Summary

Historical Figures in Psychology

• Wilhelm Vunt (Wilhelm Wundt): Recognized as the father of psychology; established the first dedicated psychology research laboratory to study senses, reaction time, and emotions.
• Edward Titchener: Student of Vunt who created the theoretical approach of structuralism.
• William James: Taught the first psychology course at Harvard University, wrote the first psychology textbook, and established functionalism.
• G. Stanley Hall: First American to earn a PhD in psychology, opened the first US lab, and served as the first president of the American Psychological Association (APA).
• Mary Whiton Calkins: Notable memory researcher and the first female president of the APA.
• Margaret Floy Washburn: Contributed to animal research; first woman to earn a psychology degree and second female APA president.
• Charles Darwin: Proposed natural selection, shaping the evolutionary psychology perspective.
• Dorothea Dix: Reformed the treatment of the mentally ill and improved conditions in insane asylums.
• Sigmund Freud: Developed psychoanalytic theory (later psychodynamic approach), focusing on the unconscious mind, id, ego, and superego.
• Ivan Pavlov: Studied reflex conditioning, known as classical conditioning, through digestive experiments with dogs.
• John Piaget: Conducted systematic studies on the cognitive development of children.
• Carl Rogers: A founder of humanistic psychology who researched personality.
• B.F. Skinner: Expanded behaviorism through operant conditioning, focusing on positive and negative consequences.
• John B. Watson: Founder of behaviorism; argued for psychology as a scientific study of observable things.

Theoretical Approaches and Modern Perspectives

• Structuralism: Uses introspection (looking inward) to analyze individual structures of consciousness.
• Functionalism: Views mental and behavioral processes as evolved functions working together.
• Gestalt Psychology: Focuses on the whole consciousness and organizational processes of perception and sensation.
• Psychoanalytic/Psychodynamic: Focuses on behaviors influenced by the unconscious mind and free association.
• Behavioralism: The study of observable, learned behaviors via classical and operant conditioning.
• Humanistic: Assumes humans are naturally good and seek self-actualization through free will.
• Sociocultural: Studies the impact of social norms, culture, religion, and gender on mental processes.
• Evolutionary: examines how modern behaviors exist due to natural selection.
• Biological: Explores brain and nervous system structures to understand the link between biological and psychological processes.
• Cognitive: Analyzes how individuals process, remember, and perceive information.

Domains of Psychology

• Basic Research: Seeks to build the knowledge base; includes biological, developmental, cognitive, educational, personality, social, positive, and psychometric domains.
• Applied Research: Focuses on practical problem-solving; includes industrial-organizational, counseling, and clinical psychology.
• Psychiatrists vs. Counselors: Psychiatrists are medical doctors (MDs) who can prescribe drugs and treat disorders; counselors assist with life challenges.

Research Methodology and Design

• Operational Definition: Clear description of procedures to allow for study replication.
• Sampling:   - Population: The total group under study.   - Sample: Selected representational group from the population.   - Random Sample: Every population member has an equal chance of participation.   - Stratified Sample: Population is divided into subcategories before random selection.
• Research Methods:   - Experiments: Observations under controlled conditions to determine cause and effect.   - Correlational Studies: Predicts the relationship between two variables but does not show causation.   - Surveys: Self-reported data vulnerable to the wording effect.   - Naturalistic Observation: Authentic real-world behavior observation.   - Case Studies: Chronological analysis of a subject; cannot be generalized to the larger population.   - Longitudinal Studies: Long-term observation of one group.   - Cross-sectional Studies: Snapshot comparison of different groups at the same time.

Experimental Variables and Statistics

• Independent Variable (IV): The cause; the factor manipulated by the researcher.
• Dependent Variable (DV): The effect; the measured outcome.
• Experimental Controls:   - Random Assignment: Equal chance for participants to be in control or experimental groups.   - Blinding: Single-blind or double-blind studies to minimize researcher bias and the placebo effect.   - Confounding Variables: Factors other than the IV that might impact the DV.
• Statistical Significance: Determined by the p-value; data is significant if $p \leq 0.05$ (less than $5\%$ chance results were due to chance). A p-value of $0.80$ means results are likely due to chance.
• Central Tendency: Mean (average), Median (middle score), and Mode (most frequent score).
• Variability: Range (highest score minus lowest) and Standard Deviation (average distance from the mean).
• Distributions:   - Normal Distribution: Symmetrical bell-shaped curve where mean, median, and mode are at center ($0$).   - Skews: Positive (scores clustered left/low) and Negative (scores clustered right/high).   - Standardized Scores: Z-scores compare scores across distributions; Percentile Rank indicates the percentage of scores at or below a specific value (e.g., median is the $50^{th}$ percentile).
• Correlation Coefficient: Strength of relationship between $-1$ and $+1$. Positive coefficients ($0$ to $1$) show variables moving together; negative coefficients ($0$ to $-1$) show an inverse relationship.

Ethical Guidelines

• Governing Bodies: The American Psychological Association (APA) sets conduct codes; the Institutional Review Board (IRB) approves human studies; the IACUC oversees animal research.
• Ethical Principles: Informed consent, privacy, confidentiality, and protection from unnecessary risk or harm.
• Historical Failures: The Stanford Prison Experiment is cited for failing to prevent physical and psychological harm.