Comprehensive Study Guide for AP Psychology Exam Notes on AP Psychology
INTRODUCTION
Psychology is defined as the scientific study of thought and behavior. Psychologists dedicate their study to understanding how the brain creates thoughts, feelings, and actions, and the ways in which internal and external environments affect them. There are four primary goals of psychology: to describe behavior, translate that description to explain behavior, predict future behavior, and ultimately influence behavior.
APPROACHES TO PSYCHOLOGY
The study of psychology is divided into several major approaches. The Biological approach focuses on the relationship between the body and the mind. The Behavioral approach is concerned mainly with a person's observable responses to stimuli. The Cognitive approach is concerned with memory, perception, thought, and other mental processes. The Humanistic approach focuses on a person's capacity for self-fulfillment and growth. Finally, the Psychodynamic approach is concerned with the influences of unconscious desires and motives.
RESEARCH STUDIES
Studies in psychology test hypotheses, which are testable explanations of observed events. For a study to be scientifically sound, it must possess both reliability and validity. Reliability means the study produces consistent results when replicated. Validity means the study accurately measures what it claims to measure. There are three types of validity: Construct validity ensures the study measures the effect that it is trying to measure; Internal validity shows that only the experimental factor caused an effect; and External validity refers to the study results applying to other situations.
TYPES OF STUDIES
A Correlational study expresses the relationship between two variables but does not imply causation. In contrast, an Experiment involves the manipulation of an independent variable in order to understand its effect on a dependent variable, which allows researchers to identify cause-and-effect relationships. Sampling is the process of choosing subjects to study. A Sample is a group of subjects selected for study, representing a subset of a population. The Population is the larger group of people about whom the researcher wants to make conclusions, so a sample should be representative of that population. Random assignment is the random placement of subjects into experimental or control groups. The Control group is the group not subject to experimental manipulation. Variables are things that can vary among subjects. The Independent variable is manipulated by the researcher to produce a change in the Dependent variable, which is measured by the researcher. A Confounding variable is any possible variable, other than the independent variable, that may cause the observed effect.
STATISTICS
Statistical analysis describes data and quantifies relationships between variables. A Frequency distribution is an arrangement of data points based on how frequently they occur. A Normal distribution is a frequency distribution with a symmetrical bell-shaped curve. Central tendency describes measures of the center of the frequency distribution. There are three types: the Mean is the arithmetic average of data points; the Median is the middle data point; and the Mode is the most frequent data point. Variability describes how the data are dispersed or spread around the mean. The Range is the distance between the highest and lowest data point. The Standard deviation (SD) is the average distance of a data point from the mean. A small SD means the scores are relatively close to the mean score, while a large SD means the scores have a wider range around the mean. Statistical significance means that the differences observed are too big to have occurred by chance. Two types of errors occur in significance testing: a Type I error is a false positive where one perceives an effect that is not there, and a Type II error is a false negative where one fails to perceive an effect that is there.
THE NERVOUS SYSTEM
The nervous system receives and transmits information. The Central nervous system (CNS) consists of the brain and spinal cord. The brain is split into right and left hemispheres, which exhibit contralateral control, meaning each hemisphere controls the opposite side of the body, and lateralization, meaning the left and right hemispheres have different functions. The three major parts of the brain are the hindbrain, midbrain, and forebrain. The Hindbrain is the top part of the spinal cord and includes the medulla, which controls basic biological functions such as breathing, swallowing, and balance; the pons, which controls facial expressions, sleep, and dreaming; and the cerebellum, which controls fine motor movements. The Midbrain coordinates basic movements with sensory information. The Forebrain is large in humans and includes the cerebral cortex and subcortical structures. These subcortical structures include the Basal ganglia, which regulates muscle contractions and movements; the Thalamus, which incorporates and relays sensory information to the cortex; the Hypothalamus, which controls motivated behavior such as eating, drinking, and sex; the Hippocampus, which helps process and receive long-term and spatial memory; and the Amygdala, which controls emotion and evaluation of stimuli.
THE CEREBRAL CORTEX
The Cerebral cortex receives sensory information and transmits motor information. The corpus callosum is a nerve tract beneath the cortex that connects the two hemispheres and allows them to communicate. The cerebral cortex consists of four lobes: the Occipital lobe processes vision; the Temporal lobe processes sound; the Parietal lobe integrates sensory systems and is involved in attention; and the Frontal lobe controls speech, learning, thinking, decision-making, and abstract thought. The Peripheral nervous system includes all nerves that spread through the body from the brain and spinal cord. This system has two divisions: the Somatic division controls voluntary muscle movements and sense organs, and the Automatic division controls involuntary actions and internal organs. The Automatic division is further divided into the Sympathetic nervous system, which gets the body ready for emergency action, and the Parasympathetic nervous system, which becomes active during states of relaxation.
NEURONS AND INFORMATION EXCHANGE
Neurons, or nerve cells, are the basic unit of the nervous system. Each neuron has three main parts: the Soma (cell body) stores energy for the cell; the Dendrite receives messages from other neurons and conducts them toward the soma; and the Axon sends messages to other neurons. The Axon ends in terminal branches (axon terminals) that contain neurotransmitters and is insulated by the Myelin sheath so signals can travel quickly. A Glial cell creates myelin, supports and guides neurons, and helps repair them. Neurons communicate by receiving and transmitting nerve impulses. The axon terminals of the presynaptic neuron are stimulated and contain synaptic vesicles, which empty neurotransmitters into the synapse, the small gap between neurons where information is exchanged. Neurotransmitters are chemicals that stimulate neurons: Excitatory neurotransmitters make neurons more likely to fire, while Inhibitory neurotransmitters make neurons less likely to fire. The Excitation threshold is the voltage difference of necessary to destabilize a neuron, causing an action potential to occur. The Action potential, or nerve impulse, is the brief change in electrical charge that destabilizes a neuron and stimulates the axon terminals to restart the process.
ENDOCRINE SYSTEM
The endocrine system is made up of hormone-secreting glands and affects communication inside the body. Hormones are chemicals that help regulate bodily functions. Glands produce these hormones and dump them into the blood-stream, through which they travel through the body. Hormones act more slowly than neurotransmitters, but their effects tend to be longer-lasting.
SENSATION AND VISION
The eye contains several critical parts: the Cornea is the protective covering where light first enters; the Lens refracts light rays to focus a flipped, inverted image onto the retina; and the Retina is a thin structure at the back of the eye containing receptor cells. These receptors include Rods, which are in the periphery and respond to black and white, functioning better in low light with more sensitivity to motion but less acuity, and Cones, which are centered in the fovea, respond to color, and provide better daytime vision and visual acuity. The Optic nerve carries visual information to the lateral geniculate nucleus of the thalamus. The Blind spot is the place where the optic nerve exits the eye and contains no receptor cells. Light waves are electromagnetic waves with Intensity, which is the amount of energy per unit of time (brightness), and Wavelength, which is the distance between two wave crests (color). There are two theories of color vision: the Trichromatic theory (Young-Helmholtz) suggests three types of cones detect red, green, and blue light, though it does not explain negative afterimages. A Negative afterimage occurs if you stare at one color and then look at white space, seeing the complementary hue. The Opponent-process theory (Hering) suggests receptor cells are arranged in pairs: red/green, blue/yellow, and black/white, where one color is stimulated while the other is inhibited.
AUDITION AND OTHER SENSES
The ear is composed of the Outer ear (pinna), which collects sound and directs it through the canal; the Tympanic membrane (eardrum), which vibrates when hit by sound; the Oval window, which separates the middle and inner ear and sends vibrations to the cochlea; and the Cochlea, a fluid-filled membrane where pressure changes stimulate Hair cells, which are auditory receptor cells that initiate nerve impulses. Sound waves are vibrations categorized by Amplitude (height of a wave/loudness) and Frequency (length of a wave/pitch). Pitch is sensed via Place theory, where hair cells respond based on location in the cochlea, and Frequency theory, where hair cells fire at different rates. Chemical senses include Smell (olfaction), where inhaled molecules excite receptors in the olfactory epithelium and the olfactory bulb gathers messages for the brain, and Taste, where taste buds on the tongue are sensitive to salty, sour, bitter, and sweet. Mechanical senses include Skin senses for pressure, pain, warmth, and cold; Vestibular senses in the semicircular canal for body orientation, balance, and head location; and the Kinesthetic sense for information about limbs from muscles, tendons, and joints.
PERCEPTION
Perception is the process of understanding and interpreting sensations. It is measured via the Absolute threshold, the least amount of stimulus observable, and the Difference threshold, the smallest change needed to perceive a just noticeable difference (jnd). Weber's law states that the size of the difference threshold is proportional to the stimulus's intensity. Perceptual cues include Perceptual constancy (size, shape, brightness) and Visual depth perception. Monocular cues, which do not require two eyes, include Interposition (closer objects are in front), Size (larger objects are closer), Linear position (smaller retinal images for distant objects), and Texture gradients (greater detail if closer). Binocular cues use two eyes, specifically Binocular or retinal disparity, which increases as an object gets farther. Motion cues like Motion parallax describe how close images change position on the retina more quickly than distant ones. Gestalt rules for grouping include Proximity (near objects belong together), Similarity (resembling objects belong together), Continuity (objects forming a line), Closure (objects making something recognized), and Common fate (objects moving in the same direction). Processing includes Bottom-up (feature analysis), starting with elements to create context, and Top-down, using schemata (mental representations of experiences) to recognize elements. Attention processes include the Cocktail party effect, where one switches attention if their name is heard, and the Stroop effect, where automatic processes like reading interfere with naming colors.
LEARNING
Learning is defined as changes in behavior arising from experience. Simple learning includes Habituation, where responses to stimuli lessen as they become familiar, and Classical conditioning (Pavlov), the creation of involuntary responses. In classical conditioning, the Unconditioned stimulus (UCS) triggers a natural Unconditioned response (UCR). A Conditioned stimulus (CS) is paired with the UCS until it produces a Conditioned response (CR), which is a learned response often identical to the UCR. Pavlov's experiment showed that a bell (CS) initially produced no response, food (UCS) produced salivation (UCR), but pairing food and the bell eventually led to the bell (CS) producing salivation (CR). Principles include Extinction (CR disappears without UCS), Spontaneous recovery (CR reappears), Generalization (CR occurs to similar stimuli), and Discrimination (CR only to a specific CS). Operant or instrumental conditioning (Skinner) involves learning based on consequences. An Operant is an instrumental response (like a rat pressing a lever), and a Reinforcer increases the likelihood of a behavior. Positive reinforcement adds something pleasant, while Negative reinforcement removes something unpleasant. A Punisher decreases behavior. Learned helplessness occurs when a subject believes unpleasant stimuli are inevitable and stops trying to change things. Operant principles include Shaping (reinforcing successive steps), Chaining (reinforcing a series of behaviors), and Extinction (response stops when reinforcement stops). Reinforcement schedules can be continuous or partial. Partial schedules include Fixed-interval (fixed time, response starts slow then increases), Variable-interval (average time, low response rate), Fixed-ratio (fixed number of responses, high rate), and Variable-ratio (average number of responses, very high rate).
MEMORY
Memory involves Encoding (acquiring information), Storage (holding it), and Retrieval (getting it back). Encoding strategies according to Craik and Lockhart include Shallow (surface features) and Deep (structural relationships and meaning). Retrieval happens via Recall (supplying info to a cue) or Recognition (deciding if info was encountered before). There are three memory systems. Sensory memory has a large capacity but very short duration (split seconds). Short-term memory (STM) or working memory has a small capacity of items and an un-rehearsed duration of . Chunking and Rehearsal increase STM capacity and duration. Long-term memory (LTM) is permanent with unlimited capacity and includes Implicit (skills), Explicit (facts/events), Semantic (general meanings), and Episodic (personal events). Forgetting results from Decay (disuse) or Displacement (items pushed out of STM). The Primacy effect (remembering early info due to rehearsal) and Recency effect (remembering last info still in STM) are observed in recall tasks. Memory is reconstructive, using schemas (organized knowledge structures) to guide comprehension. Interference in LTM occurs via Proactive interference (early learning disrupts later) or Retroactive interference (later learning disrupts earlier). Amnesia types include Anterograde (cannot form new memories) and Retrograde (cannot remember events prior to injury).
LANGUAGE, THINKING, AND INTELLIGENCE
Language uses Phonemes (smallest sound units), Morphemes (smallest units with meaning), and Syntax (word arrangement). Syntax has Surface structure (word organization) and Deep structure (meaning). Acquisition involves Babbling and Telegraphic speech (short phrases). Aphasias include Broca's (production failure) and Wernicke's (comprehension failure). Thinking involves Mental representations that are Analogical (sharing qualities with the thing represented) or Symbolic (no shared qualities). Problem solving utilizes Algorithms (step-by-step) or Heuristics (rules of thumb), such as Availability (based on frequency in mind) or Representativeness (similarity to a prototype). Intelligence theories include Spearman’s g factor, Sternberg’s three types (analytic, practical, experiential), and Gardner’s seven types (linguistic, logical, musical, spatial, kinesthetic, interpersonal, intrapersonal). Intelligence is measured via IQ tests: . Tests include the Stanford-Binet and Weschler adult scale. Testing requires standardization (uniform procedures) and norms (comparative scores).
DEVELOPMENT
Development includes learning (nurture) and maturation (nature). Infants have automatic reflexes like rooting and sucking. Adolescence involves frontal lobe myelination for self-control, and aging often brings declines in STM and attention. Social development includes Attachment, illustrated by Harlow's monkey studies (preference for soft surrogates) and Ainsworth's three styles: Secure, Resistant, and Avoidant. Socialization involves parenting styles: Autocratic (strict), Authoritative-reciprocal (firm but fair, most effective), and Permissive (few rules). Erickson defined eight psychosocial stages from Trust vs. Mistrust to Ego integrity vs. Despair. Cognitive development (Piaget) involves Assimilation (adding to schemas) and Accommodation (changing schemas). Piaget's stages are Sensory-motor (object permanence), Preoperational (symbolic, conservation), Concrete operations (logic, empathy), and Formal operations (abstract reasoning). Kohlberg’s moral stages are Preconventional (gain/punishment), Conventional (loyalty to standards), and Postconventional (universal justice).
MOTIVATION, EMOTION, AND STRESS
Motivation involves acting to satisfy a goal. Biological reasons include Homeostasis and physiological drives. Social motivation is Intrinsic (act is rewarding) or Extrinsic (outside rewards). Theories include Drive-reduction, Opponent-process (maintaining homeostasis), and Maslow's hierarchy (bodily needs to self-actualization). Emotion theories include James-Lange (perceiving bodily response), Cannon-Bard (simultaneous emotion and bodily response), and Schacter-Singer (arousal plus cognitive interpretation). Stress involves stressors (events) and stress reactions. Selye’s General adaptation syndrome includes alarm, resistance, and exhaustion. Personalities include Type A (hostile, competitive, high heart disease risk) and Type B (easygoing).
CONSCIOUSNESS AND SLEEP
Consciousness levels include Conscious, Preconscious (could be attended to), Subconscious (exists and affects us without awareness), Nonconscious (mind-controlled body processes), and Unconscious. Drugs like Agonists (mimic neurotransmitters) and Antagonists (block them) alter consciousness. Stimulants speed up the nervous system, Depressants slow it down, Opioids relieve pain, and Hallucinogens change reality perception. Hypnosis opens people to suggestion. Sleep is a state of consciousness with NREM cycles (Stage 1-4) lasting and REM cycles (dreams, paralysis) lasting . REM is vital for memory consolidation.
PERSONALITY
Personality is characterized by behaviors, attitudes, and emotions. The trait approach includes Eysenck’s three factors (Extraversion, Neuroticism, Psychoticism) and the Big Five (extroversion, neuroticism, openness, agreeableness, conscientiousness). Behavioral-cognitive approaches emphasize reinforcement and modeling. Freud’s Psychodynamic theory involves the Id (pleasure principle), Ego (reality principle), and Superego (conscience). Defense mechanisms like Repression, Displacement, Reaction formation, Rationalization, and Projection protect the ego from anxiety. Humanistic theories include Maslow’s hierarchy/self-actualization and Rogers’s self-concept (I and me). Assessments include self-reported tests like the MMPI and CPI, and projective techniques like the Rorschach (inkblots) and TAT (stories).
SOCIAL PSYCHOLOGY
Social cognition includes Social comparison (Asch’s task) and Attitudes, which can lead to Cognitive dissonance when inconsistent. Attribution can be Situational (environment) or Dispositional (internal). The Fundamental attribution error tends to attribute behavior to disposition, while the Self-serving bias takes internal credit for success and externalizes failure. Zimbardo’s prison study showed how roles change behavior. Interactions are often Exchange relationships or Love (romantic vs. companionate). Group dynamics include Polarization, Social facilitation (performance boost with audience), Bystander effect (diffusion of responsibility), Conformity, and Compliance (Milgram’s obedience study, where subjects delivered supposed shocks).
ABNORMAL PSYCHOLOGY
Abnormality is defined by culture, personal distress, functional living, danger, or legal responsibility. The Rosenhan sanity study showed the difficulty of diagnosing abnormality. Disorders in the DSM-IV include Anxiety disorders (Phobias, Agoraphobia, Social phobia, GAD, Panic disorder, and OCD with its obsessions and compulsions), Mood disorders (Major depression, Bipolar/manic depression, and Seasonal affective disorder), Dissociative disorders (Amnesia, identity), Somatoform disorders (Hypochondriasis, conversion), Schizophrenia (Positive symptoms like hallucinations/delusions and Negative symptoms like social withdrawal; types include Catatonic, Disorganized, and Paranoid), and Personality disorders (Antisocial, Narcissistic).
TREATMENT OF PSYCHOPATHOLOGY
Five main psychological therapies treat pathology. Classical psychoanalysis (Freud) uses Free association, Transference, Resistance, and Dream analysis to resolve unconscious conflicts. Psychodynamic therapy explores cultural/interpersonal factors. Humanistic therapies include Person-centered therapy (Rogers), which offers Unconditional positive regard, Authenticity, and Empathy, and Existential therapy focusing on free choice. Behavior therapies use Exposure techniques (Extinction, Systematic desensitization with an anxiety hierarchy), Aversion therapy, and Operant conditioning (Token economy, Contingency management). Cognitive therapies include Ellis’s Rational-emotive therapy and Beck’s Cognitive therapy. Biological treatments include psychopharmacology (Antidepressants like SSRIs/Prozac or MAO inhibitors/Nardil; Anxiolytics like Benzodiazepines/Valium; and Antipsychotics like Clozapine), Electroconvulsive therapy (ECT) for depression, and Surgery (prefrontal lobotomy).