AP Psychology
review & study guide

Interaction of heredity and environment

• Behavior and mental processes emerge from the interplay between inherited traits and life experiences.
• Heredity, often called "nature," encompasses genetic influences that shape physical, behavioral, and mental attributes.
• Environmental influences, known as "nurture," involve external conditions like family upbringing and educational opportunities.
• The theory of evolution highlights that behaviors and mental habits have been shaped through natural selection to enhance survival and reproduction.
• Certain applications of evolutionary ideas, such as eugenics, have been controversial due to their discriminatory implications.
• To understand genetic impacts on behavior, scientists use studies of twins, families, and adopted individuals.

Nervous system

• The central nervous system (CNS) comprises the brain and spinal cord, which coordinate all bodily functions.
• The peripheral nervous system (PNS) connects the CNS to limbs and organs, transmitting signals throughout the body.
• The autonomic nervous system, a branch of the PNS, controls unconscious activities and is further divided into sympathetic (activating) and parasympathetic (calming) systems.
• The somatic nervous system, another PNS branch, manages voluntary muscle movements.

The neuron and neural firing

• The nervous system relies on neurons, which send information, and glial cells, which give structure, insulation, waste removal, and communication support.
• A reflex arc in the spinal cord shows how the CNS and PNS coordinate quick, automatic responses to stimuli.
• Reflexes involve sensory neurons (carry incoming signals), interneurons (connect and process within the spinal cord), and motor neurons (send instructions to muscles/glands).

Nerve signaling

• All-or-nothing principle: a neuron fires fully or not at all.
• Depolarization: the inside of the neuron becomes less negative, triggering firing.
• Refractory period: a short recovery phase before the neuron can fire again.
• Resting potential: the stable state when a neuron is not firing.
• Threshold: the level of stimulation needed for firing to begin.
• Reuptake: neurotransmitters are reabsorbed after being released.
• Disruptions in these processes can play a role in conditions such as multiple sclerosis or myasthenia gravis.

Neurotransmitters

• Neurotransmitters carry signals that can be excitatory (increase chances of firing) or inhibitory (decrease chances of firing).
• Dopamine: linked to movement, motivation, and reward pathways.
• Serotonin: affects mood, sleep, and appetite.
• Norepinephrine: influences alertness and arousal.
• Glutamate: major excitatory transmitter involved in learning and memory.
• GABA: major inhibitory transmitter, linked to calming neural activity.
• Endorphins: reduce pain and create pleasure.
• Substance P: transmits pain signals.
• Acetylcholine: involved in muscle action, learning, and memory.

Hormones with neurotransmitter-like roles

• Adrenaline: boosts energy and readiness for action.
• Leptin: signals fullness and helps regulate appetite.
• Ghrelin: stimulates hunger.
• Melatonin: regulates sleep cycles.
• Oxytocin: linked to bonding, trust, and affection.

How drugs alter neurotransmission

• Agonists: increase or mimic neuron firing.
• Antagonists: block or reduce neuron firing.
• Reuptake inhibitors: prevent neurotransmitters from being reabsorbed, increasing their effect.

Drug categories and effects

• Stimulants (e.g., caffeine, cocaine): heighten neural activity and alertness.
• Depressants (e.g., alcohol): lower neural activity and slow body functions.
• Hallucinogens (e.g., marijuana): distort thinking, sensory experiences, and perception.
• Opioids (e.g., heroin): relieve pain and can produce euphoria.

Addiction and tolerance

• Continued use can lead to tolerance, meaning more of the drug is needed for the same effect.
• Long-term use may cause addiction, where stopping can trigger intense withdrawal symptoms.

Brain

• Brain stem: involuntary functions.
• Reticular activating system (RAS): voluntary movements, eye movements, and influences learning, cognition, and emotional responses.
• Reward center: motivation and pleasurable sensations.
• Cerebellum: coordinates muscle movements, balance, and procedural learning.
• Cerebral cortex
  • Divided into two hemispheres
  • Comprises of
    • Limbic system: includes the thalamus, hypothalamus, pituitary gland, hippocampus, and amygdala.
    • Corpus callosum: connects the two hemispheres, allowing communication.
    • Lobes:
      • Occipital lobes: visual information, located at the back of the brain.
      • Temporal lobes: auditory processing and language, located on the sides.
      • Parietal lobes: sensory integration and touch processing via the somatosensory cortex, located near the upper rear.
      • Frontal lobes: language, higher cognitive processes, executive functioning, and voluntary movement through the motor cortex at the back of the frontal lobes.
• Split brain research
  • Severing the corpus callosum (split-brain surgery) reveals hemisphere specialization.
  • Utilized the brain's contralateral organization by presenting stimuli to one visual field to test hemisphere functions.
• Language areas (left hemisphere)
  • Broca's area (speech production).
  • Wernicke's area (comprehension).
  • Damage to these language areas causes aphasia.
• Brain plasticity
  • Brain's capability to reorganize neural pathways, create new connections, or assume functions of damaged areas
  • Enables adaptation throughout development and after injury.
• Methods to study the brain
  • EEG and fMRI scans, case studies, and surgical procedures like lesioning

Sleep

• Consciousness varies in levels of awareness, including thoughts, feelings, and behaviors.
• Sleep and wakefulness represent different consciousness states.
• The sleep/wake cycle follows a roughly 24-hour circadian rhythm (which can be disrupted by jet lag and shift work)
• Sleep stages identified by EEG
  • NREM sleep consists of stages 1 through 3. Decreases in duration across the sleep cycle. Hypnogogic sensations occur when entering stage 1.
  • REM sleep resembles wakefulness but involves muscle relaxation. Dreaming usually happens in REM sleep. Frequency increases through the night. Deprivation leads to REM rebound.
• Activation-synthesis theory: dreams result from the brain's attempt to make sense of neural activity.
• Consolidation theory: dreams aid in memory organization and processing during sleep.
• Reasons for sleep: consolidate memories and restore depleted bodily and mental resources.
• Sleep disorders
  • Insomnia: difficulty initiating or maintaining sleep.
  • Narcolepsy: uncontrollable sleep attacks.
  • REM sleep behavior disorder: acting out dreams.
  • Sleep apnea: breathing interruptions during sleep.
  • Somnambulism: sleepwalking.

General process

• Sensation: detecting stimuli that meet threshold and converting them to brain signals.
• Absolute threshold: stimulus detected more than 50% of the time.
• Just-noticeable difference: smallest detectable change; follows Weber's law (difference proportional to original).
• Sensory adaptation: reduced sensitivity over time.
• Sensory interaction: senses influence each other; synesthesia: cross-sensory experiences.

Vision

• Retina: captures light signals; blind spot from optic nerve exit.
• Lens: focuses via accommodation; errors cause near-/farsightedness.
• Rods (periphery): see shape/motion in low light, adapt to light changes.

Color vision

• Trichromatic theory: blue, green, red cones (short/medium/long wavelengths).
• Opponent-process: ganglion cells in red/green, blue/yellow, black/white pairs explains afterimages.
• Color vision deficiency: from cone/ganglion defects, leads to dichromatism/monochromatism.
• Occipital lobe damage: prosopagnosia (face blindness), blindsight.

Hearing

• Sound: wavelength (pitch) + amplitude (loudness).
• Pitch: place theory, volley theory, frequency theory.
• Sound localization: identify source location.
• Hearing loss: conduction and sensorineural.

Smell & taste

• Smell: bypasses thalamus; pheromones: chemical signals.
• Taste: sweet, sour, salty, bitter, umami, oleogustus.
• Taste sensitivity: varies (super, medium, non-tasters).
• Smell + taste: combine for flavor.

Touch

• Skin receptors + brain: process touch.
• Heat: both warm + cold receptors activated.

Pain

• Processed in: body + brain.
• Gate control theory: pain signal regulation.
• Phantom limb: sensation/pain in missing limb.

Balance & movement

• Vestibular sense (balance): semicircular canals + brain.
• Kinesthesis: awareness of body position/movement without sight.

• Developmental psychology studies growth and change over the lifespan, focusing on both chronological stages and broader thematic issues:
  • Stability vs. change: traits may persist or evolve throughout life.
  • Nature vs. nurture: interaction of genetic inheritance and environmental factors shapes development.
  • Continuous vs. discontinuous development: growth can be gradual or occur in distinct stages.
• Research methods include cross-sectional studies (comparing different age groups at one time) and longitudinal studies (following the same individuals over time).
• Prenatal development is influenced by teratogens (environmental agents causing harm), maternal illnesses, genetic mutations, hormonal shifts, and other environmental factors.
• In infancy and childhood, development of fine and gross motor skills is critical for gaining independence.
• Reflexes such as the rooting reflex help indicate normal neurological and physical development in infants.
• Experiments using the visual cliff demonstrate that infants possess early depth perception abilities.
• Sensitive or critical periods in infancy and childhood, especially regarding language acquisition, are crucial for development; imprinting in some animals serves as a survival mechanism by forming early attachment.
• Adolescence is marked by puberty, involving the adolescent growth spurt and development of primary and secondary sex characteristics, including menarche in young people with ovaries and spermarche in young people with testes.
• Adulthood is characterized by stabilization and eventual decline in physical and sensory functions, including reductions in reproductive capability (menopause), mobility, flexibility, reaction speed, and sensory acuity for vision and hearing.
• Sex and gender critically shape socialization patterns and influence multiple dimensions of development in individuals.

• Piaget's theory explains that children build mental frameworks called schemas through processes of assimilation (adding new information to existing schemas) and accommodation (modifying schemas to fit new information).
• Sensorimotor stage (infancy to toddlerhood): featuring the development of object permanence.
• Preoperational stage (toddlerhood to early childhood), children use symbols and engage in pretend play but show limitations such as lack of conservation, difficulty with reversibility, egocentrism, and animism. They also begin to develop a theory of mind.
• Concrete operational stage (early to late childhood): brings the ability to think logically and realistically about concrete events. Children overcome earlier errors like egocentrism but struggle with abstract or systematic thinking.
• Formal operational stage (late childhood through adulthood): capacity for abstract, hypothetical, and systematic thought. However, not all individuals reach this stage.
• Vygotsky emphasized social learning where children acquire knowledge through interactions and support (scaffolding) from others, with optimal learning happening within the zone of proximal development (tasks just beyond current ability but attainable with help).
• Adult cognitive abilities change over time: crystallized intelligence (accumulated knowledge and skills) remains stable, while fluid intelligence (problem-solving and processing speed) generally decreases.
• Adults may also experience cognitive impairments such as dementia.

Communication and language development

• Language is a mutually understood system using arbitrary symbols combined into phonemes (sounds), morphemes (units of meaning), and semantics (meaning), governed by rules of grammar and syntax to create endless expressions.
• Across cultures, language development involves the use of nonverbal gestures like pointing before progressing through stages: cooing, babbling, one-word utterances, and telegraphic speech (simple two-word phrases).
• Language learners often make errors such as overgeneralizing rules.

Social, cognitive, and neurological factors in learning

• Social learning theory posits that people can acquire new behaviors by observing others without needing to experience direct consequences (vicarious conditioning).
• Individuals are more likely to imitate behaviors demonstrated by models who resemble them.
• Insight learning happens when solutions to problems appear suddenly without trial, error, or reinforcement.
• Latent learning refers to knowledge gained without reinforcement that remains hidden until needed, often shown through the use of mental representations like cognitive maps.

• Ecological systems theory: development shaped by microsystem (direct contacts), mesosystem (links between microsystems), exosystem (indirect factors), macrosystem (cultural context), chronosystem (life stage).
• Parenting styles: authoritarian, authoritative, permissive; effects differ across cultures.
• Attachment styles: secure, insecure (avoidant, anxious, disorganized); shaped by temperament and culture.
• Separation anxiety: distress when away from caregiver or around strangers.
• Attachment research: monkey studies show preferring comfort over food.
• Peer development: early play types (parallel, pretend); adolescence shows more peer reliance, egocentrism (imaginary audience, personal fable).
• Adult development: social clock defines adulthood timing; some cultures have "emerging adulthood."
• Psychosocial stages: trust/mistrust, autonomy/shame-doubt, initiative/guilt, industry/inferiority, identity/role confusion, intimacy/isolation, generativity/stagnation, integrity/despair.
• Adverse childhood experiences (ACEs): affect lifelong relationships; cultural differences in definition and impact.
• Identity formation: achievement, diffusion, foreclosure, moratorium; includes racial, ethnic, gender, sexual, religious, occupational, and family identity, exploring "possible selves."

Classical conditioning

• Behavioral perspective: emerged from learning theories focused on conditioning, emphasizing observable behavior over internal thought.
• Classical conditioning: learning occurs by associating two stimuli so one triggers a response originally caused by the other (acquisition).
• UCS (unconditioned stimulus) becomes UCR (unconditioned response). After pairing with a CS (conditioned stimulus), the response becomes a CR (conditioned response).
• Correct sequence of presenting CS and UCS is critical for learning.
• Extinction: CR disappears when CS isn't paired with UCS; spontaneous recovery: CR reappears after pairing resumes.
• Stimulus generalization: response spreads to similar stimuli
• Stimulus discrimination: response specific to the trained stimulus.
• Higher-order conditioning: a CS becomes a UCS to create new associations.
• Emotional reactions can be classically conditioned. Counterconditioning uses this principle to treat certain mental disorders.
• Taste aversion research: demonstrates one-trial learning and biological predispositions to learn some associations faster than others.
• Habituation: reduced response to repeated or prolonged exposure to a stimulus.

Operant conditioning

• Operant conditioning: behavior shaped by consequences
• Law of Effect: reinforced behaviors increase, punished behaviors decrease.
• Reinforcement/punishment can be positive (adding) or negative (removing).
• Reinforcers can be primary (biological value) or secondary (learned value).
• Discrimination: behavior occurs only in specific contexts
• Generalization: behavior spreads to similar contexts.
• Shaping: rewarding steps toward a target behavior
• Instinctive drift: some behaviors resist shaping due to biological tendencies.
• Superstitious behavior: unrelated actions reinforced by chance.
• Learned helplessness: belief that outcomes cannot be controlled, reducing effort.
• Reinforcement schedules affect learning strength:
  • Continuous: reinforcement after every correct response.
  • Partial: reinforcement based on time (fixed or variable interval) or number of responses (fixed or variable ratio). Patterns produce distinct graph shapes.

Health psychology

• Health psychology explores how biological, behavioral, and social factors combine to affect health, illness, and overall wellness.
• Stress contributes to increased vulnerability to disorders and diseases by impacting physiological systems like blood pressure, immune function, and causing headaches.
• Stressors may act as motivating challenges (eustress) or harmful pressures (distress), ranging from traumatic events to everyday hassles.
• Adverse childhood experiences (ACEs) are significant stress sources with lasting effects throughout one's life.
• General adaptation syndrome (GAS) outlines stress response in three phases:
  • Alarm reaction: immediate fight-flight-freeze activation upon encountering stress.
  • Resistance: body actively copes with stress while maintaining heightened alertness.
  • Exhaustion: occurs when resources deplete, increasing risk for illness.
• Tend-and-befriend theory suggests some individuals, especially women, respond to stress by nurturing themselves or others and seeking social bonds.
• Problem-focused coping involves actively addressing and solving the source of stress.
• Emotion-focused coping manages the emotional impact of stress using methods such as meditation, deep breathing, or medication.

Positive psychology

• Positive psychology investigates factors that enhance well-being, resilience, and emotional health.
• Expressing gratitude increases a person's sense of happiness and subjective well-being.
• Using one's unique signature strengths or virtues correlates with higher happiness levels and well-being.
• Character strengths are grouped into six virtues: wisdom, courage, humanity, justice, temperance, and transcendence.
• Posttraumatic growth refers to the positive psychological changes and personal development that can follow experiencing trauma or severe stress.

• Psychological disorders are identified by dysfunction in daily functioning, personal distress, and deviation from societal norms.

• Diagnosing disorders carries both benefits and drawbacks influenced by the disorder's nature, individual circumstances, and factors like culture, stigma, and discrimination.

• DSM (created by APA) and ICD (created by WHO) serve as standard classification guides, regularly updated with new insights.

• Psychologists often use an eclectic approach, combining multiple perspectives to understand and treat disorders.

• Behavioral perspective sees disorders as learned maladaptive responses to stimuli.

• Psychodynamic perspective attributes disorders to unconscious conflicts rooted in childhood experiences.

• Humanistic perspective links disorders to inadequate social support and failure to reach personal potential.

• Cognitive perspective focuses on dysfunctional thoughts, beliefs, and emotions as causes.

• Evolutionary perspective views disorders as behaviors that may decrease survival chances.

• Sociocultural perspective emphasizes the role of harmful social and cultural dynamics.

• Biological perspective considers physiological or genetic problems as underlying causes.

• Biopsychosocial model integrates biological, psychological, and social elements to explain disorders.

• Diathesis-stress model suggests disorders arise from genetic predispositions triggered by stressful life events.

Neurodevelopmental disorders

• Signs: Begins during developmental stages, focusing on whether behaviors align with age or maturity.
• Examples: Attention-deficit/hyperactivity disorder (ADHD) and autism spectrum disorder (ASD).
• Possible causes include environmental factors, physiological issues, and genetic influences.

Schizophrenic spectrum disorders

• Symptoms/signs: Disturbances in delusions, hallucinations, disorganized thinking or speech, abnormal motor behavior, and negative symptoms.
• Delusions are false beliefs, such as feeling persecuted or believing one has grand importance, and represent positive symptoms.
• Hallucinations are sensory experiences without external stimuli and can affect any sense.
• Disorganized speech includes nonsensical word combinations, known as "word salad," and indicates a positive symptom.
• Disorganized motor behavior may include catatonia, which manifests as either excessive excitement (positive) or immobility/stupor (negative).
• Negative symptoms reflect absent normal behaviors, such as lack of emotional expression (flat affect) or movement.
• Possible contributors are genetic predispositions, biological factors like prenatal viral infections, or neurotransmitter imbalances such as dopamine dysregulation.

Depressive disorders

• Symptoms/signs: Persistent sad, empty, or irritable moods accompanied by physical and mental changes impacting daily functioning.
• Examples include major depressive disorder and persistent depressive disorder.
• Possible causes span biological, genetic, social, cultural, behavioral, and cognitive origins.

Bipolar disorders

• Symptoms/signs: Alternating periods of mania/hypomania with periods of depression or stable mood, with cycling that varies in duration.
• Bipolar I disorder includes manic episodes (and may or may not include major depression).
• Bipolar II disorder involves hypomanic (less severe mania) episodes alternating with major depressive episodes.
• Possible contributors include biological, genetic, social, cultural, behavioral, and cognitive factors.

Anxiety disorders

• Symptoms/signs: Excessive fear or anxiety and related behavioral disturbances.
• Specific phobia is an intense fear of a particular object or situation, such as heights (acrophobia) or spiders (arachnophobia).
• Agoraphobia is fear of open/enclosed spaces or specific situations where escape is difficult.
• Panic disorder (PD) is marked by sudden panic attacks with intense fear and physical symptoms, sometimes culture-bound like ataque de nervios.
• Social anxiety disorder involves fear of being judged or watched. Taijin kyofusho is a culture-specific variant.
• Generalized anxiety disorder (GAD) involves persistent, nonspecific anxiety or fear.
• Possible contributors include learned associations, maladaptive thoughts/emotions, and biological or genetic factors.

Obsessive-compulsive and related disorders

• Symptoms/signs: Unwanted obsessions (intrusive thoughts) and compulsions (repetitive behaviors to reduce distress).
• Key disorders include obsessive-compulsive disorder (OCD) and hoarding disorder.
• Possible contributors include learned associations, unhealthy thinking/emotional patterns, and biological/genetic influences.

Dissociative disorders

• Symptoms/signs: Disruptions in consciousness, memory, identity, emotion, perception, body representation, motor control, or behavior.
• Some disorders include dissociative amnesia (with or without fugue) and dissociative identity disorder.
• Often involve trauma or extreme stress experience.

Trauma- and stressor-related disorders

• Arise after exposure to traumatic or highly stressful events, leading to psychological distress.
• Symptoms/signs: Flashbacks, mood or cognitive shifts (such as emotional detachment), heightened arousal or reactivity (such as hostility, insomnia, hypervigilance, and severe anxiety), and avoidant behavior.

Feeding and eating disorders

• Symptoms/signs: Problematic eating behaviors or food intake that harm physical health or mental functioning.
• Anorexia nervosa involves self-imposed food intake restriction whereas bulimia nervosa involves intake of large amounts of food with loss of control.
• Possible causes include biological and genetic predispositions, as well as social, cultural pressures, behavioral patterns, and cognitive factors.

Personality disorders

• Symptoms/signs: Chronic and inflexible patterns of inner experience and behavior that deviate from cultural norms, start in adolescence or early adulthood, and cause distress or impairment.
• Grouped into three clusters:
  • Cluster A (odd or eccentric): paranoid, schizoid, and schizotypal personality disorders.
  • Cluster B (dramatic, emotional, or erratic): antisocial, histrionic, narcissistic, and borderline personality disorders.
  • Cluster C (anxious or fearful): avoidant, dependent, and obsessive-compulsive personality disorders.
• Possible causes include biological, genetic, social, cultural, behavioral, and cognitive influences.

• Psychotherapy is generally effective, supported by meta-analytic research.
• Therapists must practice cultural humility and build a strong therapeutic alliance with clients.
• The adoption of psychotropic medications led to deinstitutionalization starting in the late 20th century.
• Modern treatment prefers decentralized approaches combining medication with psychological therapies.
• Ethical treatment guided by APA principles includes nonmaleficence (do no harm), fidelity, integrity, and respect for clients' rights and dignity.
• Psychodynamic therapy uses free association and dream interpretation to explore the unconscious mind.
• Cognitive therapy focuses on restructuring negative thoughts about self, world, and future (cognitive triad) and employs techniques like fear hierarchies.
• Cognitive-behavioral therapies (e.g., dialectical behavior therapy, rational-emotive behavior therapy) integrate cognitive and behavioral methods to treat disorders.
• Humanistic therapy, especially person-centered therapy, emphasizes active listening and unconditional positive regard.
• Applied behavior analysis uses conditioning principles, including exposure therapies (systematic desensitization), aversion therapy, token economies, and biofeedback to manage anxiety and depression.
• Group therapy involves multiple clients simultaneously, benefiting from social support and group dynamics, differing from one-on-one therapy.
• Hypnosis effectively treats pain and anxiety but is not reliable for memory retrieval or age regression.
• Psychoactive medications (such as antidepressants, antianxiety drugs, lithium, antipsychotics) influence neurotransmitters to treat biochemical causes of disorders but may cause side effects like tardive dyskinesia.
• Surgical or invasive interventions include psychosurgery (such as lobotomies), transcranial magnetic stimulation (TMS), and electroconvulsive therapy (ECT).