BOE ALL UNITS

Hindsight Bias – The tendency to believe, after learning an outcome, that one would have foreseen it ("I-knew-it-all-along" phenomenon).

Operational Definition – A statement of the exact procedures used to define research variables (e.g., intelligence = score on an IQ test).

Case Study – An in-depth analysis of an individual or group to reveal universal principles.

Naturalistic Observation – Observing and recording behavior in naturally occurring situations without trying to manipulate or control the situation.

Survey – A method for collecting self-reported attitudes or behaviors of people, usually by questioning a representative, random sample.

Experiment – A research method where an investigator manipulates one or more variables to observe the effect on some behavior or mental process.

Control Group – In an experiment, the group that is not exposed to the treatment and serves as a comparison.

Experimental Group – The group in an experiment that receives the variable being tested.

Population – All the cases in a group being studied, from which samples may be drawn.

Random Sample – A sample that fairly represents a population because each member has an equal chance of inclusion.

Representative Sample – A sample that accurately reflects the characteristics of the population as a whole.

Convenience Sample – A group chosen based on ease of access rather than randomness or representativeness.

Random Assignment – Assigning participants to experimental and control groups by chance, minimizing preexisting differences.

Double-Blind Procedure – An experimental procedure in which both the participants and research staff are blind to who received the treatment or placebo.

Placebo – A substance with no known medical effect used as a control in testing new drugs.

Independent Variable – The factor that is manipulated; the variable whose effect is being studied.

Dependent Variable – The outcome factor; the variable that may change in response to manipulations of the independent variable.

Statistical Significance – A statistical statement of how likely it is that an obtained result occurred by chance.

Effect Size – A quantitative measure of the magnitude of a phenomenon (e.g., difference between groups).

Standard Deviation – A computed measure of how much scores vary around the mean score.

Quantitative Measures – Data that is measured and expressed numerically (e.g., test scores, reaction time).

Qualitative Measures – Descriptive data (e.g., interview responses, observations).

Meta-Analysis – A statistical technique that combines the results of multiple studies to reach a conclusion.
Aggression – Any physical or verbal behavior intended to hurt or destroy, whether done reactively out of hostility or proactively as a calculated means to an end.

Altruism – Unselfish regard for the welfare of others, often leading to helping behaviors with no expectation of reward.

Bystander Effect – The tendency for any given bystander to be less likely to help if other people are present.

Social Loafing – The tendency for people in a group to exert less effort when pooling their efforts toward a common goal.

Reciprocity Norm – An expectation that people will help those who have helped them.

Conflict – A perceived incompatibility of actions, goals, or ideas.

Social Trap – A situation where conflicting parties, by each pursuing their self-interest, become caught in mutually destructive behavior (e.g., overfishing).

Ingroup vs. Outgroup Phenomenon – The tendency to favor one's own group (ingroup) and view others (outgroup) as different or inferior.

Out-group Homogeneity Bias – The perception that members of the outgroup are more similar to each other than they really are, while seeing the ingroup as diverse.

Fundamental Attribution Error – The tendency to overestimate the influence of personal traits and underestimate situational factors when analyzing others' behavior.

Diffusion of Responsibility – The phenomenon where individuals are less likely to help when others are present, assuming someone else will act.

Deindividuation – The loss of self-awareness and self-restraint in group situations that foster arousal and anonymity (e.g., mobs, riots).

Social Responsibility Norm – An expectation that people will help those who depend on them (e.g., children, elderly).

Stanford Prison Experiment – A study by Philip Zimbardo that revealed how quickly people adopt roles of power or submission in a simulated prison setting, often leading to abusive behavior.

Groupthink – When the desire for harmony in a decision-making group overrides a realistic appraisal of alternatives (e.g., ignoring dissent to maintain group unity).

Social Facilitation – Improved performance on simple or well-learned tasks in the presence of others.

Asch Experiment – Solomon Asch’s study showing that people will conform to group pressure even when they know the group is wrong (e.g., line-length judgments).

Milgram Study – Stanley Milgram’s obedience study where participants were willing to administer what they thought were painful electric shocks to others when instructed by an authority figure.

Foot-in-the-door Technique – A persuasion strategy in which a small request is followed by a larger one, increasing the chances of compliance.

Obedience – Compliance with a direct order or command from an authority figure.

Conformity – Adjusting one’s behavior or thinking to match a group standard.
Neurons – Nerve cells; the basic building blocks of the nervous system that transmit information via electrical and chemical signals.

Axon – The long fiber that carries neural impulses away from the neuron’s cell body to other neurons, muscles, or glands.

Soma – The cell body of a neuron; contains the nucleus and is responsible for the neuron's health and metabolism.

Dendrites – Branching extensions of a neuron that receive messages and conduct them toward the cell body.

Action Potential – A brief electrical charge that travels down an axon; how neurons communicate.

Myelin Sheath – A fatty layer that insulates axons and speeds up neural impulses. Damage can lead to disorders like multiple sclerosis.

Reuptake – The process by which neurotransmitters are taken back into the synaptic vesicles after being released into the synapse.

Endorphins – Natural, opiate-like neurotransmitters linked to pain control and pleasure.

Endocrine System – A slow-acting chemical communication system; a set of glands that secrete hormones into the bloodstream.

Pituitary Gland – The master gland of the endocrine system; under the influence of the hypothalamus, it regulates growth and controls other endocrine glands.

Glutamate – A major excitatory neurotransmitter involved in memory. Too much can cause overstimulation (e.g., seizures).

Dopamine – A neurotransmitter associated with movement, attention, learning, and the brain’s pleasure and reward system.

Acetylcholine (ACh) – A neurotransmitter involved in muscle action, learning, and memory. A deficiency is linked to Alzheimer’s disease.

Norepinephrine – A neurotransmitter involved in arousal and alertness. Undersupply can depress mood.

GABA (Gamma-Aminobutyric Acid) – A major inhibitory neurotransmitter. Undersupply linked to seizures, tremors, and insomnia.

Serotonin – A neurotransmitter that affects mood, hunger, sleep, and arousal. Undersupply linked to depression.
Cerebral Cortex – The outer layer of the brain, responsible for higher-level thinking, planning, and sensory processing.

Corpus Callosum – A large band of neural fibers connecting the two brain hemispheres and carrying messages between them.

Thalamus – The brain’s sensory control center, located on top of the brainstem; it directs messages to the sensory receiving areas in the cortex.

Hypothalamus – A neural structure lying below the thalamus; directs maintenance activities (e.g., eating, temperature) and helps govern the endocrine system via the pituitary gland.

Reticular Formation – A nerve network in the brainstem that plays an important role in controlling arousal and consciousness.

Medulla – The base of the brainstem; controls heartbeat and breathing.

Cerebellum – The "little brain" at the rear of the brainstem; processes sensory input and coordinates movement and balance.

Hippocampus – A neural center located in the limbic system; helps process explicit (conscious) memories for storage.

Amygdala – Two lima-bean-sized clusters in the limbic system linked to emotion, especially fear and aggression.

Central Nervous System (CNS) – Consists of the brain and spinal cord.

Peripheral Nervous System (PNS) – Connects the central nervous system to the rest of the body via nerves; includes the somatic and autonomic systems.
Sensation – The process by which our sensory receptors and nervous system receive and represent stimulus energies from our environment.

Perception – The process of organizing and interpreting sensory information, enabling us to recognize meaningful objects and events.

Bottom-Up Processing – Analysis that begins with the sensory receptors and works up to the brain’s integration of sensory information (data-driven).

Top-Down Processing – Information processing guided by higher-level mental processes, as when we construct perceptions based on experience and expectations.

Absolute Threshold – The minimum stimulation needed to detect a particular stimulus 50% of the time.

Just Noticeable Difference (Difference Threshold) – The minimum difference between two stimuli required for detection 50% of the time.

Signal Detection Theory – A theory predicting how and when we detect the presence of a faint stimulus (signal) amid background noise. Detection depends on experience, expectations, motivation, and alertness.

Cocktail Party Effect – The ability to focus on one voice among a crowd while ignoring others; a form of selective attention.

Selective Attention – The focusing of conscious awareness on a particular stimulus, like focusing on one conversation in a noisy room.
Circadian Rhythm – The biological clock; regular bodily rhythms (like temperature and wakefulness) that occur on a 24-hour cycle.

Sleep Apnea – A sleep disorder characterized by temporary cessations of breathing during sleep and repeated momentary awakenings.

Night Terrors – A sleep disorder mostly in children; characterized by high arousal and an appearance of being terrified, occurring during deep sleep (NREM-3).

Insomnia – Recurring problems in falling or staying asleep.

Narcolepsy – A sleep disorder characterized by uncontrollable sleep attacks, often entering REM sleep suddenly.

Somnambulism – Sleepwalking; occurs during deep NREM-3 sleep and is usually harmless and unremembered.

Delta Waves – The large, slow brain waves associated with deep sleep (NREM-3).

Sleep Spindles – Bursts of rapid, rhythmic brain-wave activity that occur during Stage 2 sleep.

Alpha Waves – The relatively slow brain waves of a relaxed, awake state.

REM Sleep – Rapid Eye Movement sleep; a recurring sleep stage during which vivid dreams commonly occur. The body is internally active but externally calm (paradoxical sleep).

Information Processing Theory – A theory suggesting that dreams help us sort out and process the day’s events and consolidate memories.

Physiological Functioning Theory – Proposes that REM sleep may help develop and preserve neural pathways.

Activation-Synthesis Theory – The theory that dreams are the brain’s attempt to synthesize random neural activity.

REM Rebound – The tendency for REM sleep to increase following REM sleep deprivation.
Shaping – A procedure in operant conditioning in which reinforcers guide behavior toward closer approximations of the desired behavior.

Partial/Intermittent Reinforcement – Reinforcing a response only part of the time; results in slower acquisition but much greater resistance to extinction.

Continuous Reinforcement – Reinforcing the desired response every time it occurs; leads to fast learning but also fast extinction.

Positive Reinforcement – Increasing behaviors by presenting positive stimuli, such as rewards. (e.g., giving candy for a correct answer)

Negative Reinforcement – Increasing behaviors by removing or reducing negative stimuli. (e.g., taking painkillers to end pain)

Operant Conditioning – A type of learning in which behavior is strengthened if followed by reinforcement or diminished if followed by punishment.

Little Albert Experiment – A classical conditioning experiment by John B. Watson where a baby was conditioned to fear a white rat by associating it with a loud noise.

B.F. Skinner – A behaviorist who developed the theory of operant conditioning using reinforcement and punishment (Skinner box experiments with pigeons/rats).

Classical Conditioning – A learning process that occurs when two stimuli are repeatedly paired; a response that is at first elicited by the second stimulus is eventually elicited by the first alone (Pavlov’s dogs).

Ivan Pavlov – A Russian physiologist known for discovering classical conditioning through experiments with dogs and salivation.

Bobo Doll Experiment – Albert Bandura's study showing that children who observed an adult acting aggressively toward a Bobo doll were more likely to imitate the aggression.

Observational Learning – Learning by observing others (also called social learning).

Modeling – The process of observing and imitating a specific behavior.

Habituation – An organism’s decreasing response to a stimulus with repeated exposure to it.

Cognitive Map – A mental representation of the layout of one's environment (e.g., a rat remembering the path in a maze).
James-Lange Theory – The theory that emotions result from our awareness of our bodily responses to emotion-arousing stimuli (e.g., “We feel afraid because we tremble”).

Cannon-Bard Theory – The theory that an emotion-arousing stimulus simultaneously triggers (1) physiological responses and (2) the subjective experience of emotion.

Schachter-Singer Theory (Two-Factor Theory) – To experience emotion, one must (1) be physically aroused and (2) cognitively label the arousal (e.g., “I’m trembling and there’s a snake, so I must be afraid”).

Yerkes-Dodson Law – The principle that performance increases with arousal only up to a point, beyond which performance decreases.

General Adaptation Syndrome (GAS) – Hans Selye’s concept of the body’s adaptive response to stress in three phases:

Mnemonic Device – Memory aids, especially those that use vivid imagery and organizational devices (e.g., PEMDAS, ROY G. BIV).

Chunking – Organizing items into familiar, manageable units (e.g., 14921776 as 1492–1776).

Serial Positioning Effect – The tendency to recall best the first and last items in a list (primacy and recency effects).

Proactive Interference – When older learning interferes with the recall of new information (e.g., old password blocks recall of new one).

Retroactive Interference – When new learning interferes with the recall of old information.

Retrograde Amnesia – Inability to retrieve information from one’s past.

Anterograde Amnesia – An inability to form new memories after an injury.

Working/Short-Term Memory – A newer understanding of short-term memory that focuses on active processing of incoming information and retrieval from long-term memory.

Long-Term Memory – The relatively permanent and limitless storehouse of the memory system.

Encoding / Storage / Retrieval –

Recall – Retrieving information learned earlier (e.g., fill-in-the-blank).

Recognition – Identifying previously learned information (e.g., multiple choice).

Gambler’s Fallacy – The mistaken belief that if something happens more frequently than normal, it will happen less frequently in the future (and vice versa), despite randomness.

Sunk-Cost Fallacy – The idea that one should continue an endeavor once an investment in money, effort, or time has been made—even if it no longer makes sense.

Misinformation Effect – Incorporating misleading information into one’s memory of an event, often as a result of suggestive questioning.
Jean Piaget – A developmental psychologist known for his theory of cognitive development in children, identifying four major stages.

Schemas – Concepts or frameworks that organize and interpret information (mental molds into which we pour experiences).

Assimilation – Interpreting new experiences in terms of existing schemas (e.g., calling all four-legged animals “dogs”).

Accommodation – Adapting current schemas to incorporate new information (e.g., learning that a cow is not a dog).
Sensorimotor Stage (birth–2 yrs) – Babies take in the world through senses and actions.

Object Permanence – Understanding that objects exist even when they cannot be seen.

Preoperational Stage (2–6/7 yrs) – Child learns language but does not comprehend mental operations of logic.

Conservation – The understanding that mass, volume, and number remain the same despite changes in form (e.g., pouring water into a taller glass).

Reversibility – Understanding that objects can be changed and then returned back to their original form (develops during concrete operations).

Concrete Operational Stage (7–11 yrs) – Children gain the mental operations that enable them to think logically about concrete events.

Formal Operational Stage (12+ yrs) – People begin to think logically about abstract concepts and hypothetical situations.
Attachment vs. Imprinting –

Nature vs. Nurture – The longstanding debate over the relative contributions of biology (genes) and experience (environment) to human development.

Phonemes – The smallest distinctive sound units in a language (e.g., "ch," "a," "t" in “chat”).

Morphemes – The smallest units of meaning in a language (e.g., “un-”, “-ed”, or standalone words like “dog”).

DSM-5 (Diagnostic and Statistical Manual of Mental Disorders, 5th Edition) – The American Psychiatric Association’s widely used system for classifying psychological disorders.

Characteristics of a Disorder – To be diagnosed as a disorder, behavior typically must be deviant, distressful, and dysfunctional.

Generalized Anxiety Disorder (GAD) – A disorder characterized by excessive and uncontrollable worry about many things for six months or more.

Phobia – An anxiety disorder marked by a persistent, irrational fear and avoidance of a specific object, activity, or situation.

Obsessive-Compulsive Disorder (OCD) – Characterized by unwanted repetitive thoughts (obsessions) and/or actions (compulsions).

Post-Traumatic Stress Disorder (PTSD) – A disorder characterized by haunting memories, nightmares, social withdrawal, and anxiety after a traumatic experience.

Major Depressive Disorder – A mood disorder in which a person experiences two or more weeks of significantly depressed mood, feelings of worthlessness, and loss of interest in activities.

Bipolar Disorder – A mood disorder in which a person alternates between hopelessness of depression and the overexcited state of mania.

Schizophrenia – A disorder marked by delusions, hallucinations, disorganized speech, and/or diminished emotional expression.

Delusions – False beliefs, often of persecution or grandeur, that may accompany psychotic disorders.

Hallucinations – Sensory experiences without sensory input (most commonly auditory in schizophrenia).

Dissociative Identity Disorder (DID) – A rare dissociative disorder in which a person exhibits two or more distinct and alternating personalities (formerly multiple personality disorder).

Anorexia Nervosa – An eating disorder in which a person maintains a starvation diet despite being significantly underweight.

Bulimia Nervosa – An eating disorder marked by binge eating followed by purging (vomiting, laxatives, fasting, or excessive exercise).

Exposure Therapy / Systematic Desensitization – A type of behavioral therapy that gradually exposes people to what they fear while teaching them relaxation techniques.

Aversion Therapy – A behavioral therapy that pairs an unwanted behavior with an unpleasant stimulus (e.g., nausea-inducing drug with alcohol).

Biomedical Therapy – The use of medications or medical procedures (e.g., electroconvulsive therapy) to treat psychological disorders.