Comprehensive Study Guide: Introductory Psychology

What Is Psychology?

• Definition of Psychology: The scientific study of behavior and mental processes.

• Goals of Psychology:

  • Description: Observing and measuring behavior and mental processes to provide clear, detailed accounts of psychological phenomena.

  • Explanation: Proposing theories—hypothesized statements about the relationships among events—to understand why behaviors or mental processes occur.

  • Prediction: Utilizing theories to derive testable hypotheses about future behaviors under specific conditions.

  • Control: Applying psychological principles for the public good to assist individuals in coping with challenges such as anxiety and depression, rather than manipulating individuals against their will.

• Types of Research:

  • Pure Research: Conducted without concern for immediate real-world applications; driven by curiosity and the pursuit of knowledge for its own sake. It frequently forms the foundation for future practical applications.

  • Applied Research: Conducted to discover solutions to specific personal or social problems.

• Fields of Specialization in Psychology:

  • Clinical Psychologists: The largest subgroup of psychologists; evaluate and treat individuals with psychological disorders through clinical interviews and psychological testing.

  • Counseling Psychologists: Assist clients with adjustment problems (academic, vocational, interpersonal) who typically do not suffer from severe psychological disorders.

  • School Psychologists: Employed by school districts to identify and assist students whose learning is hindered by cognitive, emotional, or behavioral issues.

  • Educational Psychologists: Focus on course planning, instructional design, and systemic learning factors such as motivation, intelligence, and socio-economic background.

  • Developmental Psychologists: Study physical, cognitive, social, and emotional changes occurring across the entire human life span.

  • Personality Psychologists: Identify and measure human traits, thoughts, feelings, and behavioral tendencies.

  • Social Psychologists: Investigate the nature and causes of thoughts, feelings, and behaviors in social contexts.

  • Environmental Psychologists: Examine mutual influences between human behavior and the natural or built environment.

  • Experimental Psychologists: Conduct basic research on fundamental processes such as sensation, perception, learning, memory, motivation, and emotion.

  • Industrial & Organizational Psychologists: Industrial psychologists focus on worker selection and performance; organizational psychologists study human behavior within corporate or institutional settings.

  • Human Factors Psychologists: Design technical systems, user interfaces, and equipment to maximize safety and user-friendliness.

  • Consumer Psychologists: Study shopper behavior to predict, understand, and influence consumer choices.

  • Health Psychologists: Examine the effects of stress and psychological factors on physical health and promote health-maintaining behaviors.

  • Forensic Psychologists: Apply psychological principles to the criminal justice system (e.g., evaluating sanity, consulting on jury selection, evaluating eyewitness testimony).

  • Sport Psychologists: Use cognitive techniques (e.g., positive visualization) to assist athletes in concentration, emotional regulation, and performance optimization.

Historical Foundations of Psychology

• Ancient Roots:

  • Socrates ($460\text{--}399\,\text{BCE}$): Advised "Know thyself" and introduced introspection—a method involving deliberate examination of one's own cognitive processes, thoughts, and emotions.

  • Democritus ($400\,\text{BCE}$): Proposed that behavior is composed of body and mind and raised early questions regarding free will versus environmental determinism.

  • Aristotle ($384\text{--}322\,\text{BCE}$): Authored an early systematic treatise on psychology covering personality, sensation, perception, thought, intelligence, motives, feelings, memory, and emotion. He argued that human behavior is subject to natural laws, formulated early laws of associationism, and asserted that organisms seek pleasure and avoid pain.

  • Gustav Theodor Fechner ($1801\text{--}1887$): Published Elements of Psychophysics ($1860$), demonstrating how physical events (light, sound) evoke psychological sensations that can be measured quantitatively.

  • Wilhelm Wundt ($1832\text{--}1920$): Established the first formal psychological laboratory in Leipzig, Germany, in $1879$, marking the birth of modern experimental psychology.

• Early Schools of Psychology:

  • Structuralism: Founded by Wilhelm Wundt; attempted to break conscious experience down into three basic elements: objective sensations (sight, taste), subjective feelings (emotional responses), and mental images (memories, dreams).

  • Functionalism: Founded by William James ($1842\text{--}1910$), author of the first modern psychology textbook (Principles of Psychology, $1890$). Focused on how mental processes and behaviors function to help organisms adapt to their environments. Heavily influenced by Charles Darwin's theory of evolution, asserting that adaptive behavior patterns are retained as habits.

  • Behaviorism: Founded by John Broadus Watson ($1878\text{--}1958$); posited that psychology must restrict itself strictly to observable, measurable behavior rather than unobservable conscious processes. B. F. Skinner ($1904\text{--}1990$) expanded behaviorism by demonstrating that operant behavior is maintained through reinforcement (a stimulus that follows a response and increases its frequency).

  • Gestalt Psychology: Founded in Germany by Max Wertheimer ($1880\text{--}1943$), Kurt Koffka ($1886\text{--}1941$), and Wolfgang Köhler ($1887\text{--}1967$); translates to "pattern" or "organized whole." Argued that perception cannot be reduced to basic sensory elements because perceptions are integrated wholes that give meaning to individual parts. Emphasized learning via sudden insight rather than mechanical repetition.

  • Psychoanalysis: Founded by Sigmund Freud ($1856\text{--}1939$); both a personality theory and a psychotherapeutic method. Asserts that human behavior is driven by unconscious motives, desires, and conflicts originating in early childhood experiences.

Contemporary Perspectives in Psychology

• Biological Perspective: Investigates relationships between biological structures and processes—such as brain activity, neural transmission, the endocrine system, heredity, and evolution—and behavior/mental processes.

• Cognitive Perspective: Focuses on mental processes involved in acquiring, storing, retrieving, and manipulating information (perception, memory, intelligence, language, problem solving, and decision making).

• Humanistic-Existential Perspective:

  • Humanism: Emphasizes individual self-awareness, personal growth, self-fulfillment, and the human capacity to invent oneself through conscious choice (Carl Rogers, Abraham Maslow).

  • Existentialism: Asserts that human beings are free to choose their ethical conduct and bear personal responsibility for giving meaning to their lives.

• Psychodynamic Perspective: Modern neoanalysts (e.g., Karen Horney, Erik Erikson) retain Freud's focus on internal conflict and defense mechanisms but place greater emphasis on conscious choice, self-direction, and social relationships rather than unconscious sexual impulses.

• Learning Perspectives:

  • Behavioral Approach: Emphasizes environmental determinants and habit acquisition through classical and operant conditioning.

  • Social Cognitive Theory: Combines behavioral principles with cognitive factors, arguing that people learn intentionally through observation, mental representation, and expectation formation.

• Sociocultural Perspective: Examines the impacts of ethnicity, gender, culture, and socioeconomic status on human behavior and mental processes.

• Pioneering Figures and Cultural Diversity:

  • Mary Whiton Calkins ($1863\text{--}1930$): Introduced the paired-associates method for studying memory, discovered primacy and recency effects, and became the first female president of the American Psychological Association ($1905$) after declining a substitute doctoral degree offered by Radcliffe when Harvard University denied her earned degree due to her sex.

  • Mary Salter Ainsworth ($1913\text{--}1999$): Pioneered attachment theory research through cross-cultural observation and the Strange Situation protocol.

  • Elizabeth Loftus: Demonstrated the reconstructive, malleable nature of human memory.

  • Kenneth Bancroft Clark ($1914\text{--}2005$) & Mamie Phipps Clark ($1917\text{--}1983$): Conducted the "Doll Experiment," demonstrating the negative effects of school segregation on the self-esteem of African American children, cited by the U.S. Supreme Court in Brown v. Board of Education ($1954$).

  • Jorge Sanchez: Demonstrated cultural bias in standardized intelligence testing when administered to Mexican American children.

  • Lillian Comas-Diaz: Editor of multicultural mental health journals; advanced culturally competent clinical practice.

  • Richard M. Suinn: Researched mental health, identity development, and acculturation among Asian Americans.

Methods of Research and Ethics

• The Scientific Method:

  1. Formulate a research question.

  2. State a testable hypothesis (a specific prediction regarding behavior or mental processes).

  3. Test the hypothesis using controlled experimental or observational methods.

  4. Draw conclusions based on empirical findings.

  5. Construct, refine, or revise psychological theories.

• Samples and Populations:

  • Population: The complete targeted group of interest to researchers.

  • Sample: A representative segment of the target population selected for empirical study.

  • Random Sample: A sample drawn such that every individual in the target population has an equal opportunity of being chosen.

  • Stratified Sample: A sample structured so that identified subgroups in the population are represented proportionally.

  • Volunteer Bias: Systematic error resulting from differences between individuals who volunteer to participate in research (e.g., higher interest, more free time, more liberal attitudes) and those who do not.

• Research Methods:

  • Case Study: A detailed, in-depth biography of an individual or small group obtained via interviews, records, and psychological tests (e.g., Chris Sizemore / "Three Faces of Eve"). Subject to memory distortion and interviewer bias.

  • Survey: Collecting self-reported data from large samples via questionnaires or interviews (e.g., Alfred Kinsey's $1948$ and $1953$ reports on human sexual behavior). Susceptible to recall errors, social desirability bias, and falsification.

  • Naturalistic Observation: Unobtrusive observation of organisms in their natural habitats without intervention (e.g., Jane Goodall's observations of tool use and kissing in chimpanzees).

  • Correlational Method: Mathematical technique used to determine whether two observed variables are co-related.

  • Correlation Coefficient ($r$): A statistic ranging between $-1.00$ and $+1.00$. Positive correlations indicate variables increase together; negative correlations indicate as one increases, the other decreases. Correlation does not prove causation due to potential selection factors or unmeasured third variables.

  • Experimental Method: A controlled procedure used to demonstrate cause-and-effect relationships by manipulating an independent variable and measuring its impact on a dependent variable.

  • Independent Variable: Condition manipulated by the experimenter.

  • Dependent Variable: Measured outcome presumed to depend on the independent variable.

  • Experimental Group: Participants who receive the treatment.

  • Control Group: Participants who do not receive treatment, while all other conditions are kept constant.

  • Placebo: A bogus, inactive treatment that appears genuine.

  • Blind Studies: Studies where participants are unaware of whether they received the genuine treatment or a placebo.

  • Double-Blind Studies: Studies where neither the participants nor the experimenters measuring outcomes know who received the real treatment or placebo, controlling for participant expectations and experimenter bias.

• Ethics in Research:

  • Human Participants: Overseen by institutional ethics review committees. Requires informed consent (participants agree after receiving an overview of the study and risks), protection from unacceptable harm, preservation of confidentiality, and thorough debriefing if deception is used.

  • Animal Subjects: Permitted only when no alternative exists and potential scientific benefits justify the harm. Governed by strict animal care guidelines.

• Principles of Critical Thinking:

  1. Be skeptical and keep an open mind.

  2. Insist on empirical evidence.

  3. Examine definitions of terms.

  4. Examine the underlying assumptions/premises of arguments.

  5. Be cautious in drawing conclusions from evidence.

  6. Be skeptical of anecdotal evidence.

  7. Consider alternative interpretations of research findings.

  8. Do not oversimplify complex human phenomena.

  9. Do not overgeneralize.

  10. Apply critical thinking to all areas of life.

Biology and Psychology: The Nervous System

• Neurons: Specialized cells of the nervous system that conduct electrochemical impulses. The human body contains over $100\,\text{billion}$ neurons.

  • Glial Cells: Non-neuronal cells that remove dead neurons and waste, nourish and insulate neurons, form myelin, and facilitate neural transmission.

  • Anatomy of a Neuron:

  • Cell Body (Soma): Contains the nucleus; utilizes oxygen and nutrients to generate cellular energy.

  • Dendrites: Root-like fibers extending from the soma that receive incoming messages from adjacent neurons.

  • Axon: Long, thin trunk extending from the soma that conducts impulses away toward terminal buttons.

  • Myelin Sheath: White, fatty insulator encasing many axons, accelerating impulse conduction. Disrupted in multiple sclerosis.

  • Axon Terminals / Terminal Buttons: Bulb-shaped structures at the end of axon branches containing synaptic vesicles.

• Types of Neurons:

  • Afferent (Sensory) Neurons: Transmit sensory messages from bodily receptors to the spinal cord and brain.

  • Efferent (Motor) Neurons: Transmit motor signals from the brain and spinal cord to muscles and glands.

  • Interneurons: Transmit impulses between neurons within the CNS.

• The Neural Impulse:

  • Resting Potential: The baseline electrical charge across the neural membrane when not firing, approximately $-70\,\text{mV}$ (inside is negatively charged relative to outside fluid due to chloride ions, $\text{Cl}^-$).

  • Depolarization & Action Potential: When stimulated to threshold, the neural membrane allows positively charged sodium ions ($\text{Na}^+$) to rush inside. The internal charge shifts to $+30\,\text{mV}$ to $+40\,\text{mV}$ (a total voltage shift of $110\,\text{mV}$), generating the action potential.

  • All-or-None Principle: A neuron fires an impulse of uniform strength whenever its threshold is reached; stronger stimuli increase firing frequency, not individual impulse magnitude.

  • Refractory Period: A brief recovery phase following firing during which the neuron is insensitive to new messages while $\text{Na}^+$ ions are pumped out.

• Synapses and Neurotransmitters:

  • Synapse: The junction consisting of a transmitting axon terminal button, a fluid-filled synaptic cleft, and a receiving dendrite or soma receptor site.

  • Neurotransmitters: Chemical messengers released by synaptic vesicles into the cleft that bind to specifically shaped receptor sites on receiving neurons.

  • Acetylcholine (ACh): Controls muscle contractions; excitatory at voluntary muscles, inhibitory at the heart. Essential for memory formation in the hippocampus (deficient in Alzheimer's disease). Blocked by curare and botulism (causing paralysis/suffocation).

  • Dopamine: Affects voluntary movement, learning, memory, and pleasure perception. Deficiencies cause Parkinson's disease (treated with L-dopa); overutilization/excess receptors implicated in schizophrenia (treated with phenothiazines).

  • Norepinephrine: Excitatory neurotransmitter/hormone produced in brain stem; speeds heart rate, involved in general arousal, learning, memory, and eating. Boosted by cocaine and amphetamines.

  • Serotonin: Regulates emotional arousal, mood, and sleep. Deficiencies linked to depression, eating disorders, alcoholism, and insomnia. LSD interferes with its action.

  • Gamma-Aminobutyric Acid (GABA): Major inhibitory neurotransmitter that calms anxiety; action amplified by alcohol and tranquilizers (e.g., Valium).

  • Endorphins: Endogenous morphines; inhibitory neurotransmitters that lock into pain receptor sites to block pain transmission ("runner's high").

• Divisions of the Nervous System:

  • Central Nervous System (CNS): Composed of the brain and spinal cord.

  • Spinal Cord: A column of nerves as thick as a thumb that carries sensory/motor messages and coordinates spinal reflexes (unlearned, two- or three-neuron arcs).

  • Gray Matter: Non-myelinated neurons/cell bodies involved in reflexes.

  • White Matter: Bundles of long, myelinated axons that carry messages to/from the brain.

  • Peripheral Nervous System (PNS): Connects the CNS to sensory organs, muscles, and glands.

  • Somatic Nervous System: Contains sensory (afferent) and motor (efferent) neurons; controls purposeful body movements and posture.

  • Autonomic Nervous System (ANS): Regulates involuntary body functions (glands, smooth muscles, internal organs).

    • Sympathetic Division: Most active during energy-expending responses ("fight-or-flight"); increases heart rate, accelerates respiration, dilates pupils, inhibits digestion.

    • Parasympathetic Division: Most active during energy-restoring processes; decelerates heart rate, constricts pupils, stimulates digestion.

The Brain and Endocrine System

• Brain Research Methods:

  • Electroencephalograph (EEG): Measures natural electrical activity (brain waves) using scalp electrodes.

  • Computerized Axial Tomography (CAT or CT scan): Passes narrow X-ray beams through the head to generate a 3D structural image.

  • Positron Emission Tomography (PET scan): Traces glucose metabolism in the brain using a radioactive tracer to produce a color-coded image of functional activity.

  • Magnetic Resonance Imaging (MRI): Uses a powerful magnetic field and radio waves to cause brain tissues to emit signals that produce detailed structural images.

  • Functional MRI (fMRI): Measures rapid, real-time shifts in blood flow to observe the brain in action.

• Brain Structures:

  • Hindbrain:

  • Medulla: Regulates vital involuntary functions (heart rate, blood pressure, respiration, coughing, sneezing).

  • Pons: Nerve bundle that transmits movement information; involved in respiration, sleep, arousal, and attention.

  • Cerebellum: Two-hemisphere structure controlling balance, posture, and motor coordination.

  • Midbrain & Reticular Formation:

  • Reticular Formation: Neural network ascending from hindbrain through midbrain to forebrain; regulates sleep, attention, and arousal. Severing causes coma; central nervous system depressants inhibit its activity.

  • Forebrain:

  • Thalamus: Two joined egg-shaped structures; serves as the main relay station for incoming sensory input (except smell) to the cerebral cortex; regulates sleep and attention.

  • Hypothalamus: Weighs $4\,\text{grams}$; regulates body temperature, fluid balance, hunger, thirst, sex, aggression, and the pituitary gland. Contains "start-eating" (lateral) and "stop-eating" (ventromedial) centers.

  • Limbic System: Fully evolved only in mammals; includes the amygdala (aggression, fear, vigilance), hippocampus (memory consolidation/retrieval), and parts of the hypothalamus.

  • Cerebrum: Large forebrain mass divided into two cerebral hemispheres connected by the corpus callosum ($200\,\text{million}$ nerve fibers).

• The Cerebral Cortex:

  • Wrinkled outer gray-matter layer ($1/8\,\text{inch}$ thick) responsible for thinking, language, and complex decision making.

  • Lobes:

  • Frontal Lobe: Contains the motor cortex (controls voluntary muscle movement) and the prefrontal cortex (executive center for planning, decision making, working memory).

  • Parietal Lobe: Contains the somatosensory cortex (processes skin sensations: touch, temperature, pain, movement).

  • Temporal Lobe: Contains the auditory cortex and Wernicke's area.

  • Occipital Lobe: Contains the visual cortex.

  • Language Areas:

  • Broca's Area: Located in the left frontal lobe near the motor cortex controlling speech muscles. Damage causes Broca's aphasia (slow, laborious, telegraphic speech with intact comprehension).

  • Wernicke's Area: Located in the left temporal lobe near the auditory cortex. Responds to auditory input and processes language comprehension. Damage causes Wernicke's aphasia (fluent, grammatical speech that lacks meaning and severely impaired comprehension).

  • Angular Gyrus: Translates visual words into auditory codes for Wernicke's area.

  • Hemispheric Specialization:

  • Left Hemisphere: Language, logic, mathematical computation, step-by-step problem solving.

  • Right Hemisphere: Visual-spatial relations, face recognition, music/art appreciation, emotional expression, metaphors.

  • Split-Brain Surgery: Severing the corpus callosum to treat severe epilepsy (pioneered by Bogen and Gazzaniga); reveals distinct capabilities of each isolated hemisphere.

• The Endocrine System:

  • System of ductless glands that release hormones directly into the bloodstream. Regulated via negative feedback loops.

  • Pituitary Gland: "Master gland" located below the hypothalamus; secretes Growth Hormone (GH), Prolactin (milk production), Vasopressin/Antidiuretic Hormone (ADH) (water conservation), and Oxytocin (labor contractions, milk ejection, social bonding).

  • Pineal Gland: Secretes melatonin (regulates sleep-wake cycles).

  • Thyroid Gland: Secretes thyroxin (regulates metabolism). Deficiency causes hypothyroidism or cretinism (stunted growth, intellectual disability); excess causes hyperthyroidism (excitability, weight loss).

  • Adrenal Glands:

  • Cortex: Regulated by ACTH; secretes corticosteroids (stress resistance, muscle development, sugar release).

  • Medulla: Secretes epinephrine (adrenaline) and norepinephrine (noradrenaline) during sympathetic arousal.

  • Gonads:

  • Testes: Produce testosterone (male sex organs, secondary male sex characteristics, sex drive).

  • Ovaries: Produce estrogen and progesterone (female sex characteristics, menstrual cycle, pregnancy).

• Evolution and Genetics:

  • Natural Selection: Charles Darwin's principle that adaptive genetic variations enable individuals to survive, reproduce, and pass traits to future generations.

  • Genetics: Study of heredity.

  • Chromosomes: $46$ chromosomes in $23$ pairs per cell ($23\text{rd}$ pair = sex chromosomes: $XX$ female, $XY$ male).

  • DNA: Deoxyribonucleic acid; double-helix structure with base pairs Adenine-Thymine ($A\text{-}T$) and Cytosine-Guanine ($C\text{-}G$).

  • Genes: Units of heredity ($20,000\text{--}25,000$ in humans).

  • Genotype: Full genetic code.

  • Phenotype: Actual physical/behavioral expression resulting from genotype-environment interaction.

  • Down Syndrome: Caused by an extra chromosome on the $21\text{st}$ pair (Trisomy $21$).

  • Kinship Studies:

  • Monozygotic (MZ) twins share $100\%$ genes; Dizygotic (DZ) twins share $50\%$ genes.

  • Heritability of intelligence is estimated between $40\%$ and $60\%$.

Sensation and Perception

• Foundations:

  • Sensation: Automatic stimulation of sensory receptors and transmission of sensory information to the CNS.

  • Perception: Active cognitive process of organizing and interpreting sensations into an inner representation of the world.

  • Absolute Threshold: Minimum stimulus intensity required to produce a sensation $50\%$ of the time.

  • Subliminal Stimulation: Sensory stimuli below the absolute threshold.

  • Difference Threshold & Just Noticeable Difference ($jnd$): Minimum difference in intensity required to tell two stimuli apart $50\%$ of the time.

  • Weber's Constant: Fixed fraction of stimulus intensity required to perceive a difference:

  • Light: $1/60$ (~$2\%$)

  • Lifted Weight: $1/53$ (~$2\%$)

  • Pitch: $1/333$ (~$0.3\%$)

  • Taste (saltiness): $20\%$

  • Signal-Detection Theory: Asserts that perception involves physical stimulus intensity, background noise, biological capacity, and psychological factors (training, motivation, attention).

  • Sensory Adaptation:

  • Sensitization (Positive Adaptation): Becoming more sensitive to low-intensity stimuli.

  • Desensitization (Negative Adaptation): Becoming less sensitive to constant stimuli.

• Vision:

  • Light Spectrum: Visible light ranges from $400\,\text{nm}$ (violet) to $700\,\text{nm}$ (red).

  • Anatomy of the Eye:

  • Cornea: Transparent outer surface.

  • Iris & Pupil: Iris is the colored muscle regulating pupil size (dilates in dark/sympathetic arousal).

  • Lens: Changes thickness (accommodation) to focus images on the retina. Presbyopia is age-related lens brittleness.

  • Retina: Photosensitive inner surface containing photoreceptors:

    • Rods: $125\,\text{million}$; black-and-white vision, sensitive in dim light.

    • Cones: $6.4\,\text{million}$; color vision and sharpness; concentrated in the fovea.

    • Bipolar & Ganglion Cells: Axons of ganglion cells converge to form the optic nerve.

    • Blind Spot: Area of retina where optic nerve exits (devoid of photoreceptors).

• Color Vision:

  • Dimensions: Hue (wavelength), Value (brightness), Saturation (purity).

  • Trichromatic Theory (Young-Helmholtz): Three types of cones sensitive to red, green, or blue light.

  • Opponent-Process Theory (Hering): Three opponent pairs of color receptors (red-green, blue-yellow, light-dark). Explains afterimages.

  • Color Blindness: Monochromats (totally color-blind, see black/white); Dichromats (partially color-blind to red-green or blue-yellow).

• Visual Perception:

  • Gestalt Laws: Figure-ground, Closure, Proximity, Similarity, Continuity, Common Fate.

  • Top-Down vs. Bottom-Up Processing: Top-down uses pre-existing knowledge/expectations; bottom-up assembles sensory details.

  • Depth Perception:

    • Monocular Cues: Perspective, relative size, clearness, overlapping, shadowing, texture gradient, motion parallax.

    • Binocular Cues: Retinal disparity (image differences between eyes), Convergence (inward turning of eyes).

  • Perceptual Constancies: Size, shape, color, and brightness constancy.

  • Visual Illusions: Hering-Helmholtz illusion, Müller-Lyer illusion.

  • Hearing (Audition):

• Sound Waves: Vibrations of medium; frequency measured in Hertz ($\text{Hz}$, cycles per second; human range $20\text{--}20,000\,\text{Hz}$); loudness measured in decibels ($\text{dB}$). $0\,\text{dB}$ = threshold of hearing; $>85\text{--}90\,\text{dB}$ = risk of hearing loss.

• Anatomy of the Ear:

  • Outer Ear: Funnels sound to the eardrum (tympanic membrane).

  • Middle Ear: Contains three ossicles (malleus/hammer, incus/anvil, stapes/stirrup) that amplify vibrations to the oval window.

  • Inner Ear: Cochlea (bony snail shell containing basilar membrane and organ of Corti with $16,000$ hair cells). Auditory nerve conducts impulses to temporal lobes.

• Pitch Perception Theories:

  • Place Theory: Pitch is determined by the specific location vibrating on the basilar membrane ($>4,000\,\text{Hz}$).

  • Frequency Theory: Frequency of neural firing matches sound wave frequency ($20\text{--}1,000\,\text{Hz}$).

  • Volley Principle: Alternating neural firing accounts for intermediate frequencies ($1,000\text{--}4,000\,\text{Hz}$).

• Deafness: Conductive (middle ear damage) vs. Sensorineural (inner ear / hair cell / auditory nerve damage).

  • The Other Senses:

• Smell (Olfaction): Chemical sense; airborne molecules activate receptors in the olfactory membrane $\rightarrow$ olfactory nerve.

• Taste (Gustation): Chemical sense; $10,000$ taste buds contain taste cells. Five primary tastes: sweet, sour, salty, bitter, umami (savory). Flavor = taste + odor + texture + temperature.

• Skin Senses: Touch, pressure, temperature (warmth/cold receptors), and pain (nociceptors, prostaglandins, gate theory of pain).

• Kinesthesis: Sense informing us of position and motion of body parts via joint and muscle receptors.

• Vestibular Sense: Sense of balance/equilibrium monitored by semicircular canals in the inner ear.

  • Extrasensory Perception (ESP): Precognition, psychokinesis, telepathy, clairvoyance. Unsubstantiated scientifically due to the file-drawer problem and lack of replicability.

Consciousness, Sleep, and Altered States

• Nature of Consciousness: Refers to sensory awareness, selective attention, direct inner awareness, personal unity (self), and the waking state.

• Sleep and Dreams:

  • Circadian Rhythm: 24-hour cycle regulated by the suprachiasmatic nucleus (SCN) of the hypothalamus and melatonin from the pineal gland.

  • Stages of Sleep:

  • Waking: Beta waves (high frequency, low amplitude).

  • Relaxed: Alpha waves ($8\text{--}13\,\text{Hz}$).

  • NREM Stage 1: Theta waves ($6\text{--}8\,\text{Hz}$), hypnagogic state.

  • NREM Stage 2: Sleep spindles ($12\text{--}16\,\text{Hz}$) and K-complexes.

  • NREM Stages 3 & 4: Deep sleep; Delta waves ($0.5\text{--}3\,\text{Hz}$).

  • REM Sleep: Rapid Eye Movement; paradoxical sleep (brain waves resemble Stage 1 awake state, but muscle paralysis occurs); $80\%$ of dreams occur here.

• Functions of Sleep: Physical rejuvenation, stress recovery, memory consolidation, brain development.

• Dreams:

  • Continuity Hypothesis: Dreams reflect daily memories ("residue of the day").

  • Freudian Theory: Expression of unconscious desires and wish fulfillment.

  • Activation-Synthesis Model: Brain's synthesis of random neural firing in the pons/reticular formation.

• Sleep Disorders:

  • Insomnia: Persistent difficulty falling or staying asleep.

  • Narcolepsy: Sudden, irresistible "sleep attacks" accompanied by sleep paralysis.

  • Sleep Apnea: Temporary cessation of breathing during sleep due to airway obstruction.

  • Deep-Sleep Disorders: Occur in Stage 3/4; include sleep terrors, bedwetting, and sleepwalking (somnambulism).

  • Altered States of Consciousness:

• Hypnosis: Suggestible trance state; explained by role theory (acting out expectations) and response set theory.

• Meditation: Transcendental Meditation (TM; mantra-based, produces relaxation response), Mindfulness Meditation (MM; non-judgmental present focus).

• Biofeedback Training (BFT): Systematic feedback of bodily functions (EMG, EEG) enabling voluntary control over autonomic processes.

  • Substance Use Disorders:

• Characterized by loss of control over usage, social impairment, risky use, tolerance (need for higher doses), and abstinence syndrome (withdrawal symptoms).

• Depressants: Slow CNS activity. Includes alcohol (GABA agonist, lowers inhibitions), opiates/opioids (morphine, heroin, fentanyl, methadone; endorphin agonists, relieve pain), and barbiturates.

• Stimulants: Increase CNS activity. Includes amphetamines (Ritalin/Adderall for ADHD), cocaine (blocks dopamine, norepinephrine, serotonin reuptake), and nicotine (stimulates epinephrine, acetylcholine).

• Hallucinogenics: Produce hallucinations. Includes marijuana (THC), LSD, mescaline, PCP.

Learning

• Definitions:

  • Behavioral: A relatively permanent change in behavior resulting from practice or experience.

  • Cognitive: The process by which organisms make relatively permanent changes in how they represent the environment.

• Classical Conditioning (Ivan Pavlov):

  • Unconditioned Stimulus (UCS): Stimulus eliciting an unlearned response (e.g., meat powder).

  • Unconditioned Response (UCR): Unlearned response to a UCS (e.g., salivation to meat).

  • Conditioned Stimulus (CS): Previously neutral stimulus that elicits a CR after pairing with UCS (e.g., tone).

  • Conditioned Response (CR): Learned response to a CS (e.g., salivation to tone).

  • Extinction: Loss of CS's ability to elicit CR after repeated presentation without UCS.

  • Spontaneous Recovery: Recurrence of an extinguished CR after passage of time.

  • Generalization: Evoking CR by stimuli similar to the CS.

  • Discrimination: Responding differently to similar stimuli based on whether they predict the UCS.

  • Higher-Order Conditioning: Pairing a neutral stimulus with an established CS to create a new CS.

  • Applications: Taste aversion (single-trial learning, long CS-UCS delay, adaptive), "Little Albert" experiment (conditioned fear of white rat; Watson & Rayner), Counterconditioning (Mary Cover Jones; pairing feared rabbit with cookies for Peter), Flooding, Systematic Desensitization.

• Operant Conditioning (Edward L. Thorndike & B. F. Skinner):

  • Law of Effect (Thorndike): Responses stamped in by rewards, stamped out by punishments.

  • Operant Behavior: Voluntary behavior that operates on or manipulates the environment.

  • Reinforcement:

  • Positive Reinforcer: Increases response frequency when presented.

  • Negative Reinforcer: Increases response frequency when removed.

  • Primary Reinforcers: Unlearned (e.g., food, water, pain relief).

  • Secondary (Conditioned) Reinforcers: Acquired through association with primary reinforcers (e.g., money, grades).

  • Punishments: Decreases response frequency. Positive punishment (apply aversive stimulus) vs. Negative punishment (remove pleasant stimulus / time-out).

  • Schedules of Reinforcement:

  • Fixed-Interval (FI): Reinforcement after a fixed time (produces fixed-interval scallops).

  • Variable-Interval (VI): Reinforcement after variable time intervals (steady response rate).

  • Fixed-Ratio (FR): Reinforcement after a fixed number of responses (high response rate).

  • Variable-Ratio (VR): Reinforcement after variable numbers of responses (highest, most resistant to extinction; e.g., slot machines).

  • Applications: Shaping (successive approximations), Behavior modification, Programmed learning, Token economies.

• Cognitive Factors in Learning:

  • Latent Learning (Tolman): Learning that remains unexpressed until motivation/reinforcement is present; involves forming cognitive maps.

  • Contingency Theory (Rescorla): Learning occurs when the CS provides predictive information about the UCS.

  • Observational Learning (Bandura): Acquisition of skills by observing models; vicarious reinforcement; mirror neurons.

Memory

• Kinds of Memory:

  • Explicit (Declarative) Memory: Memory for specific information.

  • Episodic Memory: Autobiographical events ("I remember…").

  • Semantic Memory: General knowledge and facts ("I know…").

  • Implicit (Nondeclarative/Procedural) Memory: Memory for skills and habits ("I do…"); demonstrated through actions and priming.

  • Retrospective vs. Prospective Memory: Recalling past information vs. remembering to perform actions in the future (event-based or time-based).

• Processes of Memory:

  • Encoding: Transforming sensory input into psychological formats (visual, acoustic, or semantic codes).

  • Storage: Maintaining information over time via maintenance rehearsal (rote repetition) or elaborative rehearsal (relating new info to known info).

  • Retrieval: Locating stored info and returning it to consciousness using retrieval cues.

• Stages of Memory (Atkinson-Shiffrin Model):

  • Sensory Memory: Sensory registers hold impressions briefly (Iconic memory $<1\,\text{s}$, Echoic memory several seconds).

  • Short-Term Memory (STM / Working Memory): Holds info up to a minute without rehearsal; capacity is $7 \pm 2$ chunks (George Miller); subject to serial-position effect (primacy and recency effects), displacement, and interference.

  • Long-Term Memory (LTM): Relatively permanent storage with unlimited capacity; organized hierarchically; subject to the tip-of-the-tongue (TOT) phenomenon, context-dependent memory, and state-dependent memory.

• Forgetting and Biology of Memory:

  • Memory Tasks: Recognition, Recall, Relearning (method of savings; Ebbinghaus's forgetting curve shows rapid initial loss then leveling off).

  • Interference Theory: Retroactive interference (new learning interferes with old) vs. Proactive interference (old learning interferes with new).

  • Amnesia:

  • Infantile Amnesia: Inability to recall events before age 3 (due to immature hippocampus, incomplete myelination, lack of language).

  • Anterograde Amnesia: Inability to form new long-term memories following trauma (e.g., patient H.M.).

  • Retrograde Amnesia: Inability to recall events preceding trauma.

  • Biology: Memory traces/engrams, long-term potentiation (LTP), neurotransmitters (ACh, serotonin, glutamate), hippocampus (consolidation), prefrontal cortex (executive function/working memory).

Thinking, Language, and Intelligence

• Thinking and Problem Solving:

  • Concepts: Mental categories used to group objects/events; organized into hierarchies; taught via prototypes and exemplars.

  • Problem Solving: Requires understanding the problem.

  • Algorithms: Systematic procedures guaranteed to find a solution (e.g., formulas, systematic random search).

  • Heuristics: Rules of thumb that simplify problem solving (e.g., means-end analysis, analogy heuristic).

  • Factors Influencing Problem Solving: Expertise (parallel processing), mental sets (persisting with previous strategies), insight (sudden reorganization / Aha! experience), incubation, and functional fixedness (viewing objects only in terms of their familiar function).

• Decision Making and Heuristics:

  • Representativeness Heuristic: Judging sample likelihood based on how well it matches population prototypes.

  • Availability Heuristic: Estimating frequency based on how easily examples come to mind.

  • Anchoring and Adjustment Heuristic: Using initial estimates as anchors and adjusting insufficiently.

  • Framing Effect: Influence of wording/context on decisions.

  • Motivated Reasoning: Evaluating evidence in ways that confirm pre-existing beliefs.

• Language:

  • Properties: Semanticity (sounds/signs have meaning), Infinite Creativity (producing novel sentences), Displacement (communicating about other times/places).

  • Language Development: Prelinguistic (crying, cooing, babbling) $\rightarrow$ Holophrases ($11\text{--}13\,\text{months}$) $\rightarrow$ Telegraphic speech ($2\,\text{years}$) $\rightarrow$ Overregularization (applying regular grammar rules to irregular words).

  • Theories: Learning theory (imitation/reinforcement) vs. Nativist theory (Noam Chomsky; Language Acquisition Device [LAD], universal grammar).

• Intelligence:

  • Definition: General mental capability to reason, plan, solve problems, think abstractly, and learn from experience.

  • Theories:

  • Charles Spearman: General factor ($g$) and specific factors ($s$).

  • Louis Thurstone: 8 Primary Mental Abilities.

  • Howard Gardner: Multiple Intelligences (language, math, spatial, kinesthetic, musical, interpersonal, intrapersonal, naturalist, existential).

  • Robert Sternberg: Triarchic Theory (Analytical, Creative, Practical).

  • Emotional Intelligence (Mayer, Salovey): Self-insight, empathy, emotion regulation.

  • Creativity: Ability to generate novel/useful solutions; relies on divergent thinking (generating multiple possibilities) rather than convergent thinking (narrowing to one best answer).

  • Measurement:

  • Stanford-Binet Intelligence Scale (SBIS): Yielded Mental Age (MA); Stern formula: $\text{IQ} = \frac{\text{MA}}{\text{CA}} \times 100$.

  • Wechsler Scales: WAIS, WISC; yield verbal, performance, and deviation IQs ($\text{mean} = 100$, $\text{S.D.} = 15$).

  • Nature vs. Nurture: Heritability estimated at $40\text{--}60\%$; Flynn Effect shows generational IQ gains due to environmental factors.

Motivation and Emotion

• Motivation:

  • Concepts: Motives, Needs (physiological/psychological), Drives, Incentives.

  • Theories:

  • Evolutionary Perspective: Species-specific instincts and fixed action patterns.

  • Drive-Reduction Theory: Primary/acquired drives; homeostasis (maintaining steady states).

  • Search for Stimulation: Stimulus motives (exploring, manipulating).

  • Humanistic Theory: Maslow's hierarchy of needs (physiological, safety, love/belonging, esteem, self-actualization).

  • Cognitive Perspective: Seeking cognitive consistency; cognitive-dissonance theory.

• Hunger and Eating Disorders:

  • Hunger Mechanisms: Mouth (chewing/swallowing satiety), stomach contractions/pangs, blood sugar/glucose levels, hypothalamus (Ventromedial Nucleus [VMN] = stop-eating center $\rightarrow$ damage causes hyperphagia; Lateral Hypothalamus = start-eating center $ ightarrow$ damage causes aphagia).

  • Obesity: $BMI \ge 30$; biological factors (genetics, adaptive thermogenesis, fat-to-muscle ratio) and psychological/environmental factors.

  • Eating Disorders: Anorexia nervosa (extreme fear of weight gain, distorted body image, severe weight loss), Bulimia nervosa (binge eating and purging), female athlete triad.

• Sexual Motivation and Orientation:

  • Hormones: Testosterone activates sex drive in both males and females.

  • Sexual Response Cycle (Masters & Johnson): Excitement, Plateau, Orgasm, Resolution. Characterized by vasocongestion and myotonia. Males experience a refractory period.

  • Sexual Orientation: Direction of erotic attraction (homosexual, heterosexual, bisexual, pansexual); influenced by prenatal sex hormones and genetics.

  • Gender Identity: Psychological sense of being female, male, or trans.

• Achievement Motivation: Drive to accomplish tasks and meet standards. Evaluated via the Thematic Apperception Test (TAT). Extrinsic (performance goals) vs. Intrinsic (learning goals) motives.

• Emotion:

  • Components: Physiological arousal, cognitive appraisal, behavioral tendencies.

  • Expression: Universal facial expressions for 6 basic emotions (anger, disgust, fear, happiness, sadness, surprise; Paul Ekman).

  • Facial-Feedback Hypothesis: Facial expressions can directly influence emotional feelings.

  • Theories of Emotion:

  • James-Lange Theory: External stimuli trigger specific bodily responses, which produce emotional experiences.

  • Cannon-Bard Theory: External stimuli simultaneously trigger bodily responses and emotional experiences.

  • Cognitive Appraisal Theory (Schachter-Singer): General physiological arousal + cognitive appraisal of situation $\rightarrow$ emotional label.

Voyage Through the Life Span

• Prenatal Development:

  • Germinal Stage: Conception to $2\,\text{weeks}$; zygote divides and implants in uterine wall.

  • Embryonic Stage: $2\text{--}8\,\text{weeks}$; major organ systems differentiate; head grows faster than body (cephalocaudal); sex differentiation occurs at $7\,\text{weeks}$ if testosterone is present; protected by amniotic sac, nourished via placenta and umbilical cord.

  • Fetal Stage: $3\,\text{months}$ to birth; organ systems mature, movements detected, gains weight.

• Childhood:

  • Reflexes: Rooting, sucking, withdrawal, Moro (startle), palmar (grasp), Babinski (toe fanning).

  • Motor Development: Invariant maturation sequence (rolling over, sitting, crawling, walking).

  • Perceptual Development: Visually track light, color vision at $3\,\text{months}$, visual cliff depth perception at $6\text{--}8\,\text{months}$, preference for human faces (Fantz).

  • Cognitive Development (Piaget):

  • Sensorimotor Stage ($0\text{--}2\,\text{years}$): Sensory/motor coordination; development of object permanence ($8\text{--}12\,\text{months}$).

  • Preoperational Stage ($2\text{--}7\,\text{years}$): Use of words/symbols; egocentrism, animism, artificialism, one-dimensional thinking, lack of conservation, objective responsibility.

  • Concrete Operational Stage ($7\text{--}12\,\text{years}$): Adult logic with tangible objects; decentration, conservation, reversibility, subjective moral judgment.

  • Sociocultural Theory (Vygotsky): Transmission of cognitive skills through social interaction; Zone of Proximal Development (ZPD) and scaffolding.

  • Moral Development (Kohlberg):

  • Preconventional: Stage 1 (Obedience/punishment), Stage 2 (Naive hedonistic/satisfying needs).

  • Conventional: Stage 3 (Good-boy/girl orientation), Stage 4 (Law-and-order).

  • Postconventional: Stage 5 (Contractual/legalistic), Stage 6 (Universal ethical principles).

  • Social and Emotional Development:

  • Erikson's Psychosocial Stages: Trust vs. Mistrust ($0\text{--}1$), Autonomy vs. Shame/Doubt ($1\text{--}3$), Initiative vs. Guilt ($3\text{--}5$), Industry vs. Inferiority ($6\text{--}12$).

  • Attachment (Ainsworth): Secure, Avoidant, Ambivalent/Resistant; contact comfort (Harlow); imprinting (Lorenz).

  • Parenting Styles (Baumrind): Authoritative (strict + warm), Authoritarian (strict + cold), Permissive (warm + lax), Uninvolved (cold + lax).

• Adolescence and Adulthood:

  • Adolescence: Puberty, growth spurt, menarche, brain development (prefrontal cortex immaturity), imaginary audience, personal fable, ego identity versus role diffusion (Erikson).

  • Emerging Adulthood ($18\text{--}25\,\text{years}$): Identity exploration, instability, self-focus, feeling in-between, possibilities (Arnett).

  • Adulthood: Physical peak in $20\text{s}$; menopause in $40\text{s}\text{--}50\text{s}$; crystallized intelligence increases while fluid intelligence declines; generativity versus stagnation (middle adulthood); ego integrity versus despair (late adulthood); selective optimization with compensation.

Personality: Theory and Measurement

• Psychodynamic Perspective:

  • Freud's Structures: Id (pleasure principle, unconscious), Ego (reality principle, conscious self), Superego (moral principle, conscience).

• Psychosexual Stages: Oral, Anal (anal-retentive vs. anal-expulsive), Phallic (Oedipus/Electra complex, identification), Latency, Genital.

• Neo-Freudians: Carl Jung (analytical psychology, collective unconscious, archetypes), Alfred Adler (individual psychology, inferiority complex, creative self), Karen Horney (social relationships, basic anxiety), Erik Erikson (psychosocial development, ego identity).

  • Trait Perspective:

• Hippocrates: Four humors (yellow bile/choleric, blood/sanguine, phlegm/phlegmatic, black bile/melancholic).

• Hans Eysenck: Two dimensions: Introversion-Extraversion and Emotional Stability-Instability (Neuroticism).

• Five-Factor Model ("Big Five"): Extraversion, Agreeableness, Conscientiousness, Neuroticism, Openness to Experience.

  • Learning-Theory Perspectives:

• Behaviorism: Personality shaped by situational variables and reinforcement history.

• Social Cognitive Theory (Bandura): Personality formed by interaction of person variables (expectancies, self-efficacy, subjective values) and situational variables; observational learning; gender-schema theory.

  • Humanistic-Existential Perspective:

• Maslow: Need for self-actualization.

• Rogers: Self theory; self-concept, frames of reference, unconditional positive regard vs. conditional positive regard, conditions of worth, self-ideals.

  • Sociocultural Perspective:

• Individualism vs. Collectivism: Individualists define self via personal traits/goals; Collectivists define self via group membership/relationships.

• Acculturation: Assimilation, separation, biculturalism.

  • Measurement of Personality:

• Objective Tests: Standardized questionnaires with limited response options (e.g., Minnesota Multiphasic Personality Inventory [MMPI-2]).

• Projective Tests: Ambiguous stimuli onto which test-takers project personality (e.g., Rorschach Inkblot Test, Thematic Apperception Test [TAT]).

Psychological Disorders

• Criteria for Abnormal Behavior: Unusualness, faulty perception/interpretation of reality, severe personal distress, self-defeating behavior, dangerousness, social unacceptability.

• Perspectives: Demonological model, Medical model, Diathesis-stress model, Biopsychosocial model.

• Classification: Diagnostic and Statistical Manual of Mental Disorders (DSM-5).

• Specific Psychological Disorders:

  • Anxiety Disorders: Specific phobic disorders (acrophobia, claustrophobia, agoraphobia), Social anxiety disorder, Panic disorder (abrupt panic attacks), Generalized anxiety disorder (persistent free-floating anxiety).

  • Obsessive-Compulsive and Related Disorders: OCD (obsessions = thoughts, compulsions = behaviors), Hoarding disorder, Body dysmorphic disorder.

  • Trauma- and Stressor-Related Disorders: Posttraumatic Stress Disorder (PTSD; intrusive memories, flashbacks, lasts $>1\,\text{month}$), Acute stress disorder (occurs within a month of trauma).

  • Dissociative Disorders: Dissociative Identity Disorder (DID; multiple personalities), Dissociative Amnesia (sudden memory loss), Depersonalization-Derealization Disorder (feeling detached from self/reality).

  • Somatic Symptom and Related Disorders: Illness anxiety disorder (unfounded belief of having serious disease), Conversion disorder (loss of physical function without medical cause; la belle indifférence).

  • Mood Disorders: Bipolar disorder (mood swings between manic and depressive phases), Major depressive disorder (deep depression, psychomotor retardation, learned helplessness, internal/stable/global attributional styles).

  • Schizophrenia: Psychotic disorder involving loss of reality contact. Positive symptoms (hallucinations, delusions of grandeur/persecution/reference), Negative symptoms (flat affect, mutism, avolition), Catatonia (waxy flexibility). Caused by dopamine overutilization, prefrontal cortex deficits, enlarged ventricles, and genetic vulnerability.

• Personality Disorders: Inflexible, maladaptive behavior patterns. Includes Paranoid, Schizoid, Schizotypal, Antisocial (lack of guilt/empathy, frequent conflict with law), Borderline (instability in relationships, self-image, mood), and Avoidant personality disorders.

Methods of Therapy

• History: Asylums (Bedlam), Humanitarian reform (Philippe Pinel, William Tuke, Dorothea Dix), Mental hospitals, Community mental health movement.

• Psychotherapy Approaches:

  • Psychodynamic Therapies: Traditional psychoanalysis (free association, resistance, transference, dream analysis, wish fulfillment, catharsis, insight) vs. Modern psychodynamic (ego analysis, directive, face-to-face).

  • Humanistic Therapies: Client-centered therapy (Rogers; nondirective, unconditional positive regard, empathy, genuineness) vs. Gestalt therapy (Perls; directive, integration of conflicting personality parts).

  • Behavior Therapy / Modification: Systematic desensitization (Wolpe; fear hierarchy, deep muscle relaxation), Virtual therapy, Modeling, Aversive conditioning, Operant conditioning (shaping, successive approximations, token economy, social skills training, biofeedback training).

  • Cognitive Therapies: Beck's cognitive therapy (challenging cognitive errors/distortions), Ellis's Rational Emotive Behavior Therapy (REBT; confronting irrational beliefs), Cognitive Behavioral Therapy (CBT).

  • Group Therapies: Advantages (economical, peer support, social skills practice); Couple therapy; Family therapy (systems approach, identified patient); Self-help/support groups (AA 12-step program).

  • Evidence-Based Practices: Therapies validated through randomized controlled experiments.

• Biological Therapies:

  • Drug Therapy: Antianxiety drugs (benzodiazepines/Valium; CNS depressants, risk of rebound anxiety), Antipsychotic drugs (phenothiazines/Thorazine, clozapine; block dopamine), Antidepressants (SSRIs, SNRIs; increase serotonin/norepinephrine), Mood stabilizers (lithium carbonate for bipolar disorder).

  • Electroconvulsive Therapy (ECT): Electric shock inducing convulsions; used as a last resort for severe major depression.

  • Psychosurgery: Prefrontal lobotomy (severing prefrontal lobe pathways; discontinued due to severe side effects), Gamma knife surgery.

Social Psychology

• Attitudes and Persuasion:

  • Attitudes: Enduring cognitive, emotional, and behavioral tendencies.

  • A-B Problem: Attitudes do not always predict behavior; prediction improved by specificity, attitude strength, vested interest, and accessibility.

  • Persuasion: Elaboration Likelihood Model (Central route = logic/evidence vs. Peripheral route = emotional cues, attractiveness, rewards); two-sided arguments, fear appeals, foot-in-the-door technique.

  • Cognitive Dissonance: Leon Festinger's theory; people are motivated to reduce discomfort caused by conflicting cognitions/behaviors (effort justification, attitude-discrepant behavior).

• Prejudice and Discrimination:

  • Prejudice: Negative evaluation of a group.

  • Discrimination: Negative behavior toward a group.

  • Stereotyping: Erroneous assumption that all group members share identical traits.

  • Sources: Dissimilarity, social conflict, social learning, information processing, in-group/out-group categorization.

• Attraction and Love:

  • Attraction: Influenced by physical appearance, gender differences in mate selection, the attraction-similarity hypothesis, propinquity, and reciprocity.

  • Triangular Model of Love (Sternberg): Love consists of Intimacy, Passion, and Commitment. Consummate love contains all three.

• Social Perception and Attribution:

  • Primacy & Recency Effects: Impact of first vs. recent impressions.

  • Attribution Theory: Dispositional (internal) vs. Situational (external) attributions; fundamental attribution error (attributing others' behavior to internal traits); actor-observer effect (attributing others' actions to internal traits but our own to situation); self-serving bias (attributing successes to internal factors and failures to external factors).

• Social Influence:

  • Obedience to Authority: Stanley Milgram studies; $65\%$ of participants delivered maximum $450\text{-volt}$ XXX shocks due to socialization, perception of legitimate authority, foot-in-the-door, and buffers.

  • Conformity: Solomon Asch studies; $75\%$ of participants conformed to erroneous group line-length judgments at least once due to social norms and desire for approval.

• Aggression and Group Behavior:

  • Aggression: Influenced by genetics, testosterone, frustration, learning/modeling.

  • Group Behavior:

  • Social Facilitation: Performance on simple tasks is enhanced in groups due to arousal/evaluation apprehension.

  • Social Loafing: Reduced effort in groups due to diffusion of responsibility.

  • Group Decision Making: Social decision schemes (majority-wins, truth-wins, two-thirds, first-shift).

  • Group Polarization & Risky Shift: Taking more extreme positions in groups.

  • Groupthink: Flawed group decision making caused by pressure to conform, dynamic leadership, and perceived invulnerability.

  • Deindividuation: State of reduced self-awareness and lowered concern for social evaluation in mobs.

  • Altruism & Bystander Effect: Unselfish helping behavior inhibited in crowds due to diffusion of responsibility.

Appendix: Statistics in Psychology

• Descriptive Statistics: Summarizes raw data.

  • Frequency Distribution: Ordered data set showing score frequencies (represented via frequency histograms or frequency polygons).

  • Measures of Central Tendency:

  • Mean ($\bar{X}$): Arithmetic average ($\bar{X} = \frac{\sum X}{N}$). Sensitive to extreme scores.

  • Median: Middle score (beneath which $50\%$ of scores fall).

  • Mode: Most frequently occurring score (distributions with two modes are bimodal).

  • Measures of Variability:

  • Range: Highest score minus lowest score.

  • Standard Deviation ($\text{S.D.}$): Measure of score spread around the mean ($\text{S.D.} = \sqrt{\frac{\sum d^2}{N}}$, where $d = X - \bar{X}$).

• The Normal Curve: An idealized, symmetrical, bell-shaped distribution where mean, median, and mode coincide at the center. Approximately $68.26\%$ of cases fall within $\pm 1\,\text{S.D.}$ of the mean, and $95.44\%$ fall within $\pm 2\,\text{S.D.}$

• Correlation Coefficient: Statistic ($r$) ranging between $-1.00$ and $+1.00$ describing direction and strength of relationship between two variables.

• Inferential Statistics: Mathematical procedures used to determine whether findings from samples can be generalized to target populations.

  • Statistically Significant Differences: Differences between sample groups that are unlikely to be due to chance fluctuation ($p < 0.05$ or $p < 0.01$). Dependent on difference between group means, sample size, and variability.