Chapters 1-4

Wilhelm Wundt (p. 3): Known as the “father of psychology,” he established the first psychology laboratory in Germany in 1879 and focused on studying consciousness through introspection.

G. Stanley Hall (p. 3): A student of Wundt who established the first psychology lab in the U.S. and founded the American Psychological Association (APA), serving as its first president.

William James (p. 4): A philosopher-psychologist who founded functionalism and wrote The Principles of Psychology, one of the first psychology textbooks.

Mary Whiton Calkins (p. 4): A pioneering memory researcher and the first woman president of the APA; she was denied a Harvard degree despite completing all the requirements.

Margaret Floy Washburn (p. 5): The first woman to earn a Ph.D. in psychology; known for her work in animal behavior and motor theory development.

Sigmund Freud (p. 5): The founder of psychoanalysis, a theory of personality and therapy focusing on unconscious motives and childhood experiences.

John B. Watson (p. 6): Founder of behaviorism; famously conducted the “Little Albert” experiment demonstrating conditioned emotional responses.

B. F. Skinner (p. 6): A leading behaviorist who developed the theory of operant conditioning using reinforcement and punishment to shape behavior.

Carl Rogers (p. 6): A humanistic psychologist who emphasized the importance of unconditional positive regard, empathy, and the client-centered approach to therapy.

Ivan Pavlov (p. 9): A Russian physiologist known for discovering classical conditioning through his experiments with dogs and salivation.

Jean Piaget (p. 9): A developmental psychologist known for his theory of cognitive development in children.

Charles Darwin (p. 10): Naturalist who developed the theory of evolution by natural selection; his ideas inspired evolutionary psychology.

Dorothea Dix (p. 14): A reformer who advocated for the humane treatment of the mentally ill and helped establish mental hospitals in the U.S.

Hindsight Bias (p. 31): The tendency to believe, after learning an outcome, that one would have foreseen it ("I-knew-it-all-along" phenomenon).

Critical Thinking (p. 35): Thinking that does not blindly accept arguments and conclusions; it examines assumptions, evaluates evidence, and assesses conclusions.

Theory (p. 38): An explanation using an integrated set of principles that organizes observations and predicts behaviors or events.

Hypothesis (p. 38): A testable prediction, often implied by a theory.

Operational Definition (p. 39): A carefully worded statement of the exact procedures (operations) used in a research study.

Replication (p. 39): Repeating the essence of a research study, usually with different participants in different situations, to see if the findings extend to other circumstances.

Case Study (p. 40): A descriptive technique in which one individual or group is studied in depth to reveal universal principles.

Naturalistic Observation (p. 40): Observing and recording behavior in naturally occurring situations without trying to manipulate or control the situation.

Survey (p. 42): A technique for ascertaining the self-reported attitudes or behaviors of a particular group, usually by questioning a representative sample.

Sampling Bias (p. 43): A flawed sampling process that produces an unrepresentative sample.

Population (p. 43): All those in a group being studied, from which samples may be drawn.

Random Sample (p. 43): A sample that fairly represents a population because each member has an equal chance of inclusion.

Correlation (p. 46): A measure of the extent to which two factors vary together and how well one predicts the other.

Correlation Coefficient (p. 46): A statistical index of the relationship between two things (from −1.0 to +1.0).

Scatterplot (p. 46): A graphed cluster of dots that represents the values of two variables; the slope suggests the direction of the relationship.

Illusory Correlation (p. 50): The perception of a relationship where none exists.

Experiment (p. 51): A research method in which an investigator manipulates one or more factors (independent variables) to observe the effect on a dependent variable.

Experimental Group (p. 51): The group exposed to the treatment in an experiment.

Control Group (p. 51): The group not exposed to the treatment; serves as a comparison for evaluating the effect of the treatment.

Random Assignment (p. 51): Assigning participants to experimental and control groups by chance, minimizing preexisting differences.

Double-Blind Procedure (p. 51): An experimental procedure in which both participants and research staff are ignorant about whether participants received the treatment or a placebo.

Placebo Effect (p. 52): Experimental results caused by expectations alone; any effect on behavior caused by the administration of an inert substance or condition.

Independent Variable (p. 52): The factor that is manipulated; the variable whose effect is being studied.

Confounding Variable (p. 52): A factor other than the independent variable that might produce an effect in an experiment.

Dependent Variable (p. 52): The outcome that is measured; the variable that may change when the independent variable is manipulated.

Validity (p. 53): The extent to which a test or experiment measures or predicts what it is supposed to.

Descriptive Statistics (p. 57): Numerical data used to measure and describe characteristics of groups, including measures of central tendency and variation.

Mode (p. 57): The most frequently occurring score in a distribution.

Mean (p. 57): The arithmetic average of a distribution, obtained by adding the scores and dividing by the number of scores.

Median (p. 57): The middle score in a distribution; half the scores are above it and half are below.

Skewed Distribution (p. 58): A representation of scores that lack symmetry around their average value.

Range (p. 58): The difference between the highest and lowest scores in a distribution.

Standard Deviation (p. 58): A computed measure of how much scores vary around the mean score.

Normal Curve (p. 59): A symmetrical, bell-shaped curve that describes the distribution of many types of data.

Inferential Statistics (p. 60): Numerical data that allow one to generalize—to infer from sample data the probability of something being true of a population.

Statistical Significance (p. 60): A statistical statement of how likely it is that an obtained result occurred by chance.

Culture (p. 65): The enduring behaviors, ideas, attitudes, values, and traditions shared by a group of people and transmitted from one generation to the next.

Informed Consent (p. 68): Giving potential participants enough information about a study to enable them to choose whether they wish to participate.

Debriefing (p. 68): The post-experimental explanation of a study, including its purpose and any deceptions, to its participants.

Biological Psychology (p. 77): The scientific study of the links between biological (genetic, neural, hormonal) and psychological processes.

Neuron (p. 78): A nerve cell; the basic building block of the nervous system.

Dendrites (p. 78): Branching extensions of a neuron that receive messages and conduct impulses toward the cell body.

Axon (p. 78): The neuron extension that passes messages through its branches to other neurons or to muscles or glands.

Myelin Sheath (p. 78): A fatty tissue layer segmentally encasing the axons of some neurons; enables faster transmission of impulses.

Action Potential (p. 78): A neural impulse; a brief electrical charge that travels down an axon.

Refractory Period (p. 79): A period of inactivity after a neuron has fired.

Threshold (p. 80): The level of stimulation required to trigger a neural impulse.

All-or-None Response (p. 80): A neuron's reaction of either firing (with a full-strength response) or not firing at all.

Synapse (p. 80): The junction between the axon tip of the sending neuron and the dendrite or cell body of the receiving neuron.

Neurotransmitters (p. 80): Chemical messengers that cross the synaptic gaps between neurons.

Reuptake (p. 80): A neurotransmitter's reabsorption by the sending neuron.

Endorphins (p. 82): Natural, opiate-like neurotransmitters linked to pain control and pleasure.

Agonist (p. 82): A molecule that increases a neurotransmitter's action.

Antagonist (p. 83): A molecule that inhibits or blocks a neurotransmitter's action.

Nervous System (p. 86): The body’s speedy, electrochemical communication network, consisting of all the nerve cells of the peripheral and central nervous systems.

Central Nervous System (CNS) (p. 86): The brain and spinal cord.

Peripheral Nervous System (PNS) (p. 86): The sensory and motor neurons that connect the CNS to the rest of the body.

Nerves (p. 86): Bundled axons that form neural “cables” connecting the CNS with muscles, glands, and sense organs.

Sensory (Afferent) Neurons (p. 86): Neurons that carry incoming information from the sensory receptors to the CNS.

Motor (Efferent) Neurons (p. 86): Neurons that carry outgoing information from the CNS to the muscles and glands.

Interneurons (p. 87): Neurons within the CNS that communicate internally and intervene between sensory inputs and motor outputs.

Somatic Nervous System (p. 87): The part of the PNS that controls the body’s skeletal muscles.

Autonomic Nervous System (ANS) (p. 87): The part of the PNS that controls the glands and the muscles of the internal organs.

Sympathetic Nervous System (p. 87): Arouses the body, mobilizing its energy in stressful situations.

Parasympathetic Nervous System (p. 87): Calms the body, conserving its energy.

Reflex (p. 89): A simple, automatic response to a sensory stimulus.

Endocrine System (p. 90): The body’s “slow” chemical communication system; a set of glands that secrete hormones into the bloodstream.

Hormones (p. 90): Chemical messengers that are manufactured by the endocrine glands and travel through the bloodstream.

Adrenal Glands (p. 91): Glands that help arouse the body in times of stress by releasing epinephrine and norepinephrine.

Pituitary Gland (p. 91): The endocrine system’s most influential gland; regulates growth and controls other endocrine glands.

Lesion (p. 94): Tissue destruction; a brain lesion is a naturally or experimentally caused destruction of brain tissue.

Electroencephalogram (EEG) (p. 95): An amplified recording of the waves of electrical activity sweeping across the brain’s surface.

CT (Computed Tomography) Scan (p. 95): A series of X-ray photographs taken from different angles to show brain structure.

PET (Positron Emission Tomography) Scan (p. 95): A visual display of brain activity that detects where a radioactive form of glucose goes during a task.

MRI (Magnetic Resonance Imaging) (p. 95): A technique that uses magnetic fields and radio waves to produce images of brain anatomy.

fMRI (Functional MRI) (p. 96): Reveals brain function as well as structure by comparing successive MRI scans.

Brainstem (p. 97): The oldest part and central core of the brain, responsible for automatic survival functions.

Medulla (p. 97): The base of the brainstem; controls heartbeat and breathing.

Thalamus (p. 97): The brain’s sensory control center; it directs messages to the sensory receiving areas in the cortex.

Reticular Formation (p. 98): A nerve network that plays an important role in controlling arousal.

Cerebellum (p. 98): The “little brain” at the rear of the brainstem; coordinates movement and balance.

Limbic System (p. 98): Neural system associated with emotions and drives.

Amygdala (p. 99): Two lima-bean-sized neural clusters in the limbic system linked to emotion.

Hypothalamus (p. 99): A neural structure lying below the thalamus; it directs maintenance activities and helps govern the endocrine system.

Cerebral Cortex (p. 104): The intricate fabric of interconnected neural cells covering the cerebral hemispheres; the body’s ultimate control and processing center.

Glial Cells (p. 104): Cells in the nervous system that support, nourish, and protect neurons.

Frontal Lobes (p. 105): Involved in speaking, muscle movements, and making plans and judgments.

Parietal Lobes (p. 105): Receives sensory input for touch and body position.

Occipital Lobes (p. 105): Includes areas that receive information from the visual fields.

Temporal Lobes (p. 105): Includes the auditory areas, each receiving information from the opposite ear.

Motor Cortex (p. 105): Controls voluntary movements.

Somatosensory Cortex (p. 107): Registers and processes body touch and movement sensations.

Association Areas (p. 109): Areas involved in higher mental functions such as learning, remembering, thinking, and speaking.

Plasticity (p. 111): The brain’s ability to change, especially during childhood, by reorganizing after damage or by building new pathways.

Neurogenesis (p. 112): The formation of new neurons.

Corpus Callosum (p. 114): The large band of neural fibers connecting the two brain hemispheres.

Split Brain (p. 114): A condition resulting from surgery that isolates the brain’s two hemispheres.

Consciousness (p. 118): Our awareness of ourselves and our environment.

Cognitive Neuroscience (p. 119): The interdisciplinary study of the brain activity linked with cognition.

Dual Processing (p. 120): The principle that information is often simultaneously processed on separate conscious and unconscious tracks.

Behavior Genetics (p. 124): The study of the relative power and limits of genetic and environmental influences on behavior.

Environment (p. 124): Every external influence, from prenatal nutrition to social support.

Chromosomes (p. 124): Threadlike structures made of DNA molecules that contain the genes.

DNA (Deoxyribonucleic Acid) (p. 124): A complex molecule containing the genetic information that makes up chromosomes.

Genes (p. 124): The biochemical units of heredity that make up chromosomes.

Genome (p. 124): The complete instructions for making an organism, consisting of all the genetic material in its chromosomes.

Identical Twins (p. 125): Twins who develop from a single fertilized egg that splits in two, creating two genetically identical organisms.

Fraternal Twins (p. 125): Twins who develop from separate fertilized eggs; genetically no closer than siblings.

Molecular Genetics (p. 129): The subfield of biology that studies the molecular structure and function of genes.

Heritability (p. 129): The proportion of variation among individuals that we can attribute to genes.

Interaction (p. 131): The interplay that occurs when the effect of one factor (such as environment) depends on another factor (such as heredity).

Epigenetics (p. 131): The study of environmental influences on gene expression that occur without a DNA change.

Evolutionary Psychology (p. 135): The study of the evolution of behavior and the mind using principles of natural selection.

Natural Selection (p. 135): The principle that inherited traits that better enable survival and reproduction are more likely to be passed on.

Mutation (p. 136): A random error in gene replication that leads to a change.

Sensation (p. 152): Process of sensing stimuli from environment through sensory organs

Perception (p. 152): Organizing and interpreting sensory information to understand it

Bottom-up Processing (p. 152): Processing sensory info starting at the sensory receptors

Top-down Processing (p. 152): Using experience and expectations to interpret sensory info

Selective Attention (p. 152): Focusing on a specific stimulus while ignoring others

Inattentional Blindness (p. 154): Missing visible objects because attention is elsewhere

Change Blindness (p. 154): Failing to notice changes in the environment

Transduction (p. 155): Converting sensory input into neural signals

Psychophysics (p. 155): Study of stimulus properties and perception

Absolute Threshold (p. 156): Minimum stimulus intensity detectable 50% of the time

Signal Detection Theory (p. 156): Predicts when a stimulus is detected amid noise

Subliminal (p. 157): Below the threshold of conscious awareness

Priming (p. 157): Exposure influencing response to later stimuli unconsciously

Difference Threshold (p. 158): Smallest detectable difference between two stimuli

Weber’s Law (p. 158): Difference threshold is a constant percentage, not fixed amount

Sensory Adaptation (p. 159): Reduced sensitivity to constant stimulus over time

Perceptual Set (p. 163): Mental predisposition to perceive one thing over another

Extrasensory Perception (ESP) (p. 167): Perceiving without sensory input (e.g., telepathy)

Parapsychology (p. 167): Study of paranormal phenomena like ESP

Wavelength (p. 171): Distance between peaks of light or sound waves

Hue (p. 172): Color determined by wavelength

Intensity (p. 172): Amount of energy in a wave; brightness or loudness

Pupil (p. 172): Opening that lets light into the eye

Iris (p. 172): Colored muscle controlling pupil size

Lens (p. 172): Focuses light on retina by changing shape

Retina (p. 172): Light-sensitive layer with rods and cones

Accommodation (p. 172): Lens changing shape to focus images

Rods (p. 173): Detect black, white, gray; function in low light

Cones (p. 173): Detect color; function in daylight

Optic Nerve (p. 173): Carries visual info to the brain

Blind Spot (p. 173): No receptors where optic nerve exits eye

Fovea (p. 173): Central point in retina with dense cones for sharp vision

Feature Detectors (p. 175): Brain cells responding to specific stimulus features (edges, lines)

Parallel Processing (p. 176): Brain processing multiple aspects of stimuli simultaneously

Young-Helmholtz Trichromatic Theory (p. 178): Retina has three color receptors (red, green, blue)

Opponent-Process Theory (p. 179): Color perception based on opposing retinal processes

Gestalt (p. 182): Brain’s tendency to integrate pieces into meaningful wholes

Figure-Ground (p. 183): Distinguishing objects (figure) from background (ground)

Grouping (p. 183): Organizing stimuli into coherent groups

Depth Perception (p. 184): Ability to see objects in 3D and judge distance

Visual Cliff (p. 184): Lab device testing depth perception in infants and animals

Binocular Cues (p. 184): Depth cues from both eyes working together

Retinal Disparity (p. 184): Slight difference between images from each eye, helps judge depth

Monocular Cues (p. 185): Depth cues available to one eye alone

Phi Phenomenon (p. 185): Illusion of movement created by flashing images in rapid succession

Perceptual Constancy (p. 186): Recognizing objects as unchanging despite sensory changes

Color Constancy (p. 187): Perceiving colors as stable under varying illumination

Perceptual Adaptation (p. 191): Ability to adjust to changed sensory input

Audition (p. 194): The sense or act of hearing

Frequency (p. 195): Number of wave cycles per second; determines pitch

Pitch (p. 195): Perception of sound frequency as high or low

Middle Ear (p. 195): Contains ossicles that amplify sound vibrations

Cochlea (p. 195): Spiral-shaped, fluid-filled inner ear structure that triggers neural impulses

Inner Ear (p. 195): Contains cochlea and vestibular organs

Sensorineural Hearing Loss (p. 197): Hearing loss from damage to cochlea or auditory nerve

Conduction Hearing Loss (p. 197): Hearing loss caused by damage to mechanical system conducting sound

Cochlear Implant (p. 198): Device that converts sounds into electrical signals for auditory nerve

Place Theory (p. 199): Pitch perception depends on where cochlea’s membrane is stimulated

Frequency Theory (p. 199): Pitch perception depends on the frequency of nerve impulses

Gate-Control Theory (p. 203): Pain signals pass through “gates” in spinal cord that can block or allow pain

Kinesthesia (p. 209): Sense of body position and movement of limbs

Vestibular Sense (p. 209): Sense of body’s balance and movement in space

Sensory Interaction (p. 210): One sense influencing another (e.g., smell influencing taste)

Embodied Cognition (p. 211): Influence of bodily sensations and actions on cognitive preferences and judgments