APPsychology2024FullVocabularyList-1

Absolute Threshold

• The smallest level of stimulus that can be detected 50% of the time.

Accommodation

• Revising existing cognitive schemas to include new information.
• Adapting or adjusting, including the eye's lens changing shape to focus at different distances.

Achievement Tests

• Evaluations to measure acquired knowledge.

Acoustic Encoding

• Converting sounds, particularly words, into a coded form for brain storage.

Acquisition

• Classical Conditioning: Initial phase where a neutral stimulus is paired with an unconditioned stimulus to elicit a conditioned response.
• Operant Conditioning: Reinforcement of a response.

Action Potential

• An electrical impulse that transmits information along a neuron's axon.

Active Listening

• A technique in Rogers' client-centered therapy where the listener restates, clarifies, and reflects on what they hear.

Adaptation-Level Phenomenon

• The tendency to judge stimuli based on past experiences.

Addiction

• A strong craving for a substance, leading to compulsive use despite harmful consequences.

Adolescence

• Developmental transition from childhood to adulthood.
• Marked by physical, psychological, and social changes.
• Begins at puberty and ends at reaching independence.

Adrenal Glands

• Glands located above the kidneys that release hormones like epinephrine and norepinephrine during stress.

Aggression

• Behaviors, either physical or verbal, intended to harm or destroy.
• Any act meant to cause harm or injury to another person.

Algorithm

• A step-by-step procedure or formula for solving a problem, ensuring an accurate solution.

Alpha Waves

• Brain waves that indicate a state of relaxation and wakefulness.

Altruism

• Selfless concern for the well-being of others.

Amnesia

• The inability to recall past events.

Amphetamines

• Stimulants that increase neural activity, leading to enhanced body functions and mood changes.

Amygdala

• Small, almond-shaped structures in the brain linked to emotional processes.

Anorexia Nervosa

• An eating disorder characterized by extreme weight loss and the persistent perception of being overweight.

Antianxiety Drugs

• Medications used to manage anxiety and reduce agitation.

Antidepressant Drugs

• Medications that treat depression by altering neurotransmitter levels.

Antipsychotic Drugs

• Medications used to manage schizophrenia and other severe mental disorders.

Antisocial Personality Disorder

• A condition where a person shows no regard for right or wrong and often manipulates or treats others harshly.

Anxiety Disorders

• Mental health disorders marked by excessive fear and anxiety.

Aphasia

• A language disorder resulting from brain damage that affects communication.

Applied Research

• Research aimed at solving practical problems.

Aptitude Tests

• Assessments intended to predict a person's ability to learn or succeed in certain areas.

Assimilation

• The process of incorporating new experiences into existing cognitive schemas.

Association Areas

• Parts of the brain involved in higher mental functions such as thinking, planning, and communicating.

Associative Learning

• Learning that certain events occur together, with the events being either two stimuli or a stimulus and a response.

Attachment

• An emotional bond that typically forms between infant and caregiver, manifesting in the infant seeking closeness and showing distress on separation.

Attention-Deficit Hyperactivity Disorder (ADHD)

• A disorder characterized by attention difficulties, hyperactivity, and impulsiveness.

Attitude

• A psychological tendency expressed by evaluating a particular entity with some degree of favor or disfavor.

Attribution Theory

• A theory that suggests how we explain someone's behavior—by attributing it either to internal dispositions or to external situations.

Audition

• The sense or act of hearing.

Autism

• A developmental disorder appearing in early childhood.
• Characterized by difficulties in communicating and forming relationships with other people and in using language and abstract concepts.

Automatic Processing

• The unconscious encoding of incidental information and well-learned information.

Autonomic Nervous System

• The part of the nervous system that controls involuntary actions and regulates bodily functions.

Availability Heuristic

• The tendency to estimate the likelihood of events based on how easily examples come to mind.

Aversive Conditioning

• A form of counterconditioning that associates an unpleasant state with an unwanted behavior.

Axon

• The long threadlike part of a nerve cell along which impulses are conducted from the cell body to other cells.

Babbling Stage

• The stage of language development in which an infant spontaneously utters nonsense sounds.

Barbiturates

• Drugs that act as central nervous system depressants.

Basal Metabolic Rate

• The rate at which the body uses energy while at rest to maintain vital functions.

Basic Research

• Scientific inquiry aimed at increasing the fundamental knowledge base of a subject.

Basic Trust

• According to Erik Erikson, a sense that the world is reliable and predictable, formed during infancy with proper care from caregivers.

Behavior Genetics

• The study of the power and limits of genetic and environmental influences on behavior.

Behavior Therapy

• The treatment of mental disorder by training the patient's responses in accordance with behavioral psychology.

Behavioral Medicine

• An interdisciplinary field combining behavioral and medical knowledge to promote health and treat disease.

Behavioral Psychology

• The scientific study of observable behavior and its explanation by principles of learning.

Behaviorism

• A theory that argues psychology should be an objective science that studies behavior without reference to mental processes.

Belief Perseverance

• The tendency to cling to one's initial belief even when faced with contrary evidence.

Binge-Eating Disorder

• An eating disorder characterized by frequent episodes of excessive eating followed by distress, guilt, or disgust.

Binocular Cues

• Visual information taken in by two eyes that enable perception of depth.

Biofeedback

• A technique that uses electronic devices to teach people how to consciously control bodily functions, such as heartbeat.

Biological Psychology

• The scientific study of the links between biological and psychological processes.

Biomedical Therapy

• Medical procedures and therapies that treat psychological disorders.

Biopsychosocial Approach

• An integrated approach that considers biological, psychological, and social factors and their complex interactions in understanding health, illness, and health care delivery.

Bipolar Disorder

• A disorder associated with episodes of mood swings ranging from depressive lows to manic highs.

Blind Spot

• The point in the visual field that corresponds to the lack of light-detecting photoreceptor cells on the optic disc of the retina.

Bottom-Up Processing

• An approach wherein there is a progression from the individual elements to the whole.

Brainstem

• The oldest part of the brain, responsible for basic vital life functions such as breathing, heartbeat, and blood pressure.

Broca’s Area

• A region in the frontal lobe of the dominant hemisphere of the hominid brain with functions linked to speech production.

Bulimia Nervosa

• An eating disorder characterized by binge eating followed by purging.

Bystander Effect

• The phenomenon that an individual is less likely to offer help to a victim when other people are present.

Cannon-Bard Theory

• The theory that emotional responses occur simultaneously with the physiological processes in response to stimuli.

Case Study

• A research method involving the detailed study of a single case that represents a diagnostic category.

Catharsis

• The process of releasing strong or repressed emotions.

Central Nervous System (CNS)

• The part of the nervous system consisting of the brain and spinal cord.

Central Route to Persuasion

• A method of persuasion that uses evidence and logical arguments to influence people.

Cerebellum

• The part of the brain at the back of the skull in vertebrates, which coordinates and regulates muscular activity.

Cerebral Cortex

• The intricate fabric of interconnected neural cells covering the cerebral hemispheres; the body's ultimate control and information-processing center.

Change Blindness

• When observers fail to notice changes in their visual field.

Chromosomes

• Thread-like structures located inside the nucleus of animal and plant cells.

Chunking

• A process by which individual pieces of information are bound together into a meaningful whole.

Circadian Rhythm

• Physical, mental, and behavioral changes that follow a 24-hour cycle.

Classical Conditioning

• A learning process that occurs through associations between an environmental stimulus and a naturally occurring stimulus.

Client-Centered Therapy

• A humanistic therapy, developed by Carl Rogers, that emphasizes the human potential for growth.

Clinical Psychology

• The branch of psychology concerned with the assessment and treatment of mental illness and disability.

Cochlea

• A spiral-shaped cavity forming a division of the inner ear and functioning in the process of hearing.

Cochlear Implant

• A device that can help provide a sense of sound to a person who is profoundly deaf or severely hard of hearing.

Cognition

• All the mental activities associated with thinking, knowing, remembering, and communicating.

Cognitive Behavioral Therapy

• A blend of cognitive and behavioral therapeutic strategies.

Cognitive Dissonance

• The theory that we act to reduce the discomfort we feel when two of our thoughts are inconsistent.

Cognitive Map

• A mental representation of the layout of one's environment.

Cognitive Neuroscience

• The interdisciplinary study of the brain activity linked with cognition (including perception, thinking, memory, and language).

Cognitive Psychology

• The scientific study of mental processes, including perception, thought, memory, and reasoning.

Cognitive Therapy

• A treatment method that involves helping the patient identify and correct any distorted thinking about self, others, or the world.

Collective Unconscious

• A term introduced by psychiatrist Carl Jung to represent a form of the unconscious that is shared among members of the same species.

Collectivism

• Giving priority to the goals of one's group and defining one's identity accordingly.

Color Constancy

• The ability to recognize colors of objects despite changes in lighting.

Companionate Love

• The deep affectionate attachment we feel for those with whom our lives are intertwined.

Concept

• A mental grouping of similar objects, events, ideas, or people.

Concrete Operational Stage

• A stage of cognitive development in Piaget's theory during which children gain the mental operations that enable them to think logically about concrete events.

Conditioned Reinforcer

• A stimulus that gains its reinforcing power through its association with a primary reinforcer.

Conditioned Response

• The learned response to a previously neutral stimulus.

Conditioned Stimulus

• A previously neutral stimulus that, after becoming associated with the unconditioned stimulus, eventually comes to trigger a conditioned response.

Conduction Hearing Loss

• Hearing loss caused by problems with the bones of the middle ear.

Cones

• Retinal receptor cells that are concentrated near the center of the retina and function in daylight or in well-lit conditions.
• The cones detect fine detail and give rise to color sensations.

Confirmation Bias

• A tendency to search for or interpret information in a way that confirms one's preconceptions.

Conflict

• A perceived incompatibility of actions, goals, or ideas.

Conformity

• Adjusting our behavior or thinking to coincide with a group standard.

Confounding Variable

• A factor other than the independent variable that might produce an effect in an experiment.

Consciousness

• Our awareness of ourselves and our environment.

Conservation

• The principle that properties such as mass, volume, and number remain constant despite changes in the forms of objects.

Content Validity

• The extent to which a test measures the behavior that is of interest.

Continuous Reinforcement

• The reinforcement of each and every correct response.

Control Group

• The group in an experiment or study that does not receive treatment by the researchers and is then used as a benchmark to measure how the other tested subjects do.

Conversion Disorder

• A disorder in which a person experiences very specific genuine physical symptoms for which no physiological basis can be found.

Coronary Heart Disease

• A disease of the blood vessels supplying the heart muscle.

Corpus Callosum

• The large band of neural fibers connecting the two brain hemispheres and carrying messages between them.

Correlation

• A measure of the relationship between two variables.

Correlation Coefficient

• A statistical index of the relationship between two things (from -1 to +1).

Counseling Psychology

• A branch of psychology that focuses on facilitating personal and interpersonal functioning across the life span.

Counterconditioning

• The process of breaking a conditioned response by training an individual to associate the conditioned stimulus with a new unconditioned stimulus.

Creativity

• The ability to produce new and valuable ideas.

Critical Period

• An optimal period shortly after birth when an organism's exposure to certain stimuli or experiences produces proper development.

Critical Thinking

• Thinking that does not blindly accept arguments and conclusions.
• Rather, it critically examines assumptions, discerns hidden values, evaluates evidence, and assesses conclusions.

Cross-Sectional Study

• A study in which people of different ages are compared with one another.

Crystallized Intelligence

• Our accumulated knowledge and verbal skills; tends to increase with age.

CT Scan

• A series of x-ray photographs taken from different angles and combined by computer into a composite representation of a slice through the body.

Culture

• The enduring behaviors, ideas, attitudes, and traditions shared by a group of people and transmitted from one generation to the next.

Debriefing

• The post-experimental explanation of a study, including its purpose and any deceptions, to its participants.

Defense Mechanisms

• In psychoanalytic theory, the ego's protective methods of reducing anxiety by unconsciously distorting reality.

Deindividuation

• The loss of self-awareness and self-restraint occurring in group situations that foster arousal and anonymity.

Deja Vu

• That eerie sense of "I've been here before."
• This is often triggered by a scene, event, or particular experience that unconsciously reminds us of an earlier episode.

Delta Waves

• The large, slow brain waves associated with deep sleep.

Delusions

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

Dendrites

• The bushy, branching extensions of a neuron that receive messages and conduct impulses toward the cell body.

Denial

• Psychoanalytic defense mechanism by which people refuse to believe or even to perceive painful realities.

Dependent Variable

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

Depressants

• Drugs (such as alcohol, barbiturates, and opiates) that reduce neural activity and slow body functions.

Depth Perception

• The ability to see objects in three dimensions although the images that strike the retina are two-dimensional; allows us to judge distance.

Developmental Psychology

• A branch of psychology that studies physical, cognitive, and social change throughout the life span.

Difference Threshold

• The minimum difference between two stimuli required for detection 50 percent of the time.

Discrimination

• Unjustifiable negative behavior toward a group and its members.
• In classical conditioning, the learned ability to distinguish between a conditioned stimulus and other stimuli that do not signal an unconditioned stimulus.

Discriminative Stimulus

• In operant conditioning, a stimulus that elicits a response after association with reinforcement.

Displacement

• Psychoanalytic defense mechanism that shifts sexual or aggressive impulses toward a more acceptable or less threatening object or person, as when redirecting anger toward a safer outlet.

Dissociation

• A split in consciousness, which allows some thoughts and behaviors to occur simultaneously with others.

Dissociative Disorders

• Disorders in which conscious awareness becomes separated from previous memories, thoughts, and feelings.

Dissociative Identity Disorder (DID)

• A rare dissociative disorder in which a person exhibits two or more distinct and alternating personalities. Also known as multiple personality disorder.

DNA (deoxyribonucleic acid)

• A complex molecule containing the genetic information that makes up the chromosomes.

Donald Meichenbaum

• Provided stress inoculation training, which taught people to reframe their thinking in stressful situations.

Double-Blind Procedure

• An experimental procedure in which both the research participants and the research staff are ignorant about whether the research participants have received the treatment or a placebo.
• Commonly used in drug-evaluation studies.

Down Syndrome

• A genetic disorder caused when abnormal cell division results in extra genetic material from chromosome 21.

Dream

• A sequence of images, emotions, and thoughts passing through a sleeping person's mind.
• Dreams are notable for their hallucinatory imagery, discontinuities, and incongruities, and for the dreamer's delusional acceptance of the content and later difficulties remembering it.

Drive-Reduction Theory

• The idea that a physiological need creates an aroused tension state (a drive) that motivates an organism to satisfy the need.

DSM-IV-TR

• The American Psychiatric Association’s Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition, Text Revision; a widely used system for classifying psychological disorders.

Dual Processing

• The principle that information is often simultaneously processed on separate conscious and unconscious tracks.

Echoic Memory

• A momentary sensory memory of auditory stimuli; if attention is elsewhere, sounds and words can still be recalled within 3 or 4 seconds.

Eclectic Approach

• An approach to psychotherapy that uses techniques from various forms of therapy, depending on the client's problems.

Ecstasy (MDMA)

• A synthetic stimulant and mild hallucinogen that produces euphoria and social intimacy, but with short-term health risks and longer-term harm to serotonin-producing neurons and to mood and cognition.

Educational Psychology

• The study of how psychological processes affect and can enhance teaching and learning.

Effortful Processing

• Encoding that requires attention and conscious effort.

Ego

• The largely conscious, "executive" part of personality that, according to Freud, mediates among the demands of the id, superego, and reality.
• The ego operates on the reality principle, satisfying the id's desires in ways that will realistically bring pleasure rather than pain.

Egocentrism

• In Piaget's theory, the preoperational child's difficulty taking another's point of view.

Electroconvulsive Therapy

• A biomedical therapy for severely depressed patients in which a brief electric current is sent through the brain of an anesthetized patient.

Electroencephalogram (EEG)

• An amplified recording of the waves of electrical activity that sweep across the brain's surface.
• These waves are measured by electrodes placed on the scalp.

Embryo

• The developing human organism from about 2 weeks after fertilization through the second month.

Emerging Adulthood

• For some people in modern cultures, a period from the late teens to mid-twenties, bridging the gap between adolescent dependence and full independence and responsible adulthood.

Emotion

• A response of the whole organism, involving (1) physiological arousal, (2) expressive behaviors, and (3) conscious experience.

Emotional Intelligence

• The ability to perceive, understand, manage, and use emotions.

Empirically Derived Test

• A test developed by testing a pool of items and then selecting those that discriminate between groups.

Empiricism

• The view that knowledge originates in experience and that science should, therefore, rely on observation and experimentation.

Encoding

• The processing of information into the memory system.

Endocrine System

• The body's "slow" chemical communication system; a set of glands that secrete hormones into the bloodstream.

Endorphins

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

Environment

• Every nongenetic influence, from prenatal nutrition to the people and things around us.

Equity

• A condition in which people receive from a relationship in proportion to what they give to it.

Estrogens

• Sex hormones, such as estradiol, secreted in greater amounts by females than by males and contributing to female sex characteristics; in nonhuman female mammals, estrogen levels peak during ovulation, promoting sexual receptivity.

Evidence-Based Practice

• Clinical decision-making that integrates the best available research with clinical expertise and patient characteristics and preferences.

Evolutionary Psychology

• The study of the evolution of behavior and the mind, using principles of natural selection.

Experiment

• A research method in which an investigator manipulates one or more factors to observe the effect on some behavior or mental process.

Experimental Group

• In an experiment, the group that is exposed to the treatment, that is, to one version of the independent variable.

Experimental Psychology

• The study of behavior and thinking using the experimental method.

Explicit Memory

• Memory of facts and experiences that one can consciously know and "declare".

Exposure Therapies

• Behavioral techniques that treat anxieties by exposing people to the things they fear and avoid.

External Locus of Control

• The perception that chance or outside forces beyond our personal control determine our fate.

Extinction

• The diminishing of a conditioned response; occurs in classical conditioning when an unconditioned stimulus does not follow a conditioned stimulus.

Extrasensory Perception

• The controversial claim that perception can occur apart from sensory input.

Extrinsic Motivation

• A desire to perform a behavior to receive promised rewards or avoid threatened punishment.

Facial Feedback

• The effect of facial expressions on experienced emotions, as when a facial expression of anger or happiness intensifies feelings of anger or happiness.

Factor Analysis

• A statistical procedure that identifies clusters of related items (called factors) on a test.

Family Therapy

• Therapy that treats the family as a system; views an individual's unwanted behaviors as influenced by, or directed at, other family members.

Feature Detectors

• Nerve cells in the brain that respond to specific features of the stimulus, such as shape, angle, or movement.

Feel-Good, Do-Good Phenomenon

• People's tendency to be helpful when already in a good mood.

Fetal Alcohol Syndrome (FAS)

• Physical and cognitive abnormalities in children caused by a pregnant woman's heavy drinking.
• In severe cases, symptoms include noticeable facial misproportions.

Fetus

• The developing human organism from 9 weeks after conception to birth.

Figure-Ground

• The organization of the visual field into objects that stand out from their surroundings.

Fixation

• The inability to see a problem from a new perspective, employing a different mental set.

Fixed-Interval Schedule

• In operant conditioning, a reinforcement schedule that reinforces a response only after a specified time has elapsed.

Fixed-Ratio Schedule

• In operant conditioning, a reinforcement schedule that reinforces a response only after a specified number of responses.

Flashbulb Memory

• A clear memory of an emotionally significant moment or event.

Fluid Intelligence

• Our ability to reason speedily and abstractly; tends to decrease during late adulthood.

fMRI (functional MRI)

A technique for revealing blood flow and, therefore, brain activity by comparing successive MRI scans. Shows brain function.

Foot-in-the-Door Technique

• The tendency for people who have agreed to a small request to comply later with a larger request.

Formal Operational Stage

• In Piaget's theory, the stage of cognitive development (normally beginning about age 12) during which people begin to think logically about abstract concepts.

Fovea

• The central focal point in the retina, around which the eye's cones cluster.

Framing

• The way an issue is posed; how an issue is framed can significantly affect decisions and judgments.

Fraternal Twins

• Twins who develop from separate fertilized eggs. They are genetically no more similar than brothers and sisters, but they share a fetal environment.

Free Association

• In psychoanalysis, a method of exploring the unconscious in which the person relaxes and says whatever comes to mind, no matter how trivial or embarrassing.

Frequency

• The number of complete wavelengths that pass a point in a given time.

Frequency Theory

• In hearing, the theory that the rate of nerve impulses traveling up the auditory nerve matches the frequency of a tone, thus enabling us to sense its pitch.

Frontal Lobes

• Portion of the cerebral cortex lying just behind the forehead; involved in speaking and muscle movements and in making plans and judgments.

Frustration-Aggression Principle

• The principle that frustration—the blocking of an attempt to achieve some goal—creates anger, which can generate aggression.

Functional Fixedness

• The tendency to think of things only in terms of their usual functions; an impediment to problem-solving.

Functionalism

• A school of psychology that focused on how mental and behavioral processes function—how they enable us to adapt, survive, and flourish.

Fundamental Attribution Error

• The tendency for observers, when analyzing another's behavior, to underestimate the impact of the situation and overestimate the impact of personal disposition.

Gate-Control Theory

• Theory that explains how the nervous system blocks or allows pain signals to pass to the brain.

Gender

• The socially influenced characteristics by which people define male and female.

Gender Identity

• Our sense of being male or female.

Gender Role

• A set of expected behaviors for males or for females.

Gender Typing

• The acquisition of a traditional masculine or feminine role.

General Adaptation Syndrome (GAS)

• Selye's concept of the body's adaptive response to stress in three stages—alarm, resistance, exhaustion.

General Intelligence

• A general intelligence factor that, according to Spearman and others, underlies specific mental abilities and is therefore measured by every task on an intelligence test.

Generalization

• The tendency, once a response has been conditioned, for stimuli similar to the conditioned stimulus to elicit similar responses.

Generalized Anxiety Disorder

• An anxiety disorder in which a person is continually tense, apprehensive, and in a state of autonomic nervous system arousal.

Genes

• The biochemical units of heredity that make up the chromosomes; segments of DNA capable of synthesizing proteins.

Genome

• The complete instructions for making an organism, consisting of all the genetic material in that organism's chromosomes.

Gestalt

• An organized whole that is perceived as more than the sum of its parts.

Glial Cells

• Cells in the nervous system that support, nourish, and protect neurons.

Glucose

• A form of sugar that circulates in the blood and provides the major source of energy for body tissues. When its level is low, we feel hunger.

Grammar

• In a language, a system of rules that enables us to communicate with and understand others.

GRIT

• A strategy designed to decrease international tensions.

Group Polarization

• The enhancement of a group's prevailing inclinations through discussion within the group.

Grouping

• The perceptual tendency to organize stimuli into coherent groups.

Habituation

• Decreasing responsiveness with repeated stimulation.
• As infants gain familiarity with repeated exposure to a visual stimulus, their interest wanes and they look away sooner.

Hallucinations

• False sensory experiences, such as seeing something in the absence of an external visual stimulus.

Hallucinogens

• Psychedelic drugs, such as LSD, that distort perceptions and evoke sensory images in the absence of sensory input.

Health Psychology

• A subfield of psychology that provides psychology's contribution to behavioral medicine.

Heritability

• The proportion of variation among individuals that we can attribute to genes.
• The heritability of a trait may vary, depending on the range of populations and environments studied.

Heuristic

• A simple thinking strategy that often allows us to make judgments and solve problems efficiently; usually speedier but also more error-prone than algorithms.

Hierarchy of Needs

• Maslow's pyramid of human needs, beginning at the base with physiological needs that must first be satisfied before higher-level safety needs and then psychological needs become active.

Higher-Order Conditioning

• A procedure in which the conditioned stimulus in one conditioning experience is paired with a new neutral stimulus, creating a second (often weaker) conditioned stimulus.

Hindsight Bias

• The tendency to believe, after learning an outcome, that one would have foreseen it.

Hippocampus

• A neural center located in the limbic system; helps process explicit memories for storage.

Homeostasis

• The tendency to maintain a balanced or constant internal state; the regulation of any aspect of body chemistry, such as blood glucose, around a particular level.

Hormones

• Chemical messengers that are manufactured by the endocrine glands, travel through the bloodstream, and affect other tissues.

Hue

• The dimension of color that is determined by the wavelength of light; what we know as the color names blue, green, etc.

Human Factors Psychology

• The study of how people and machines interact and the design of safe and easily used machines and environments.

Humanistic Psychology

• A historically significant perspective that emphasized the growth potential of healthy people.

Hypnosis

• A social interaction in which one person (the hypnotist) suggests to another (the subject) that certain perceptions, feelings, thoughts, or behaviors will spontaneously occur.

Hypochondriasis

• A somatoform disorder involving excessive concern about health and disease.

Hypothalamus

• A neural structure lying below the thalamus; it directs several maintenance activities (eating, drinking, body temperature), helps govern the endocrine system via the pituitary gland, and is linked to emotion and reward.

Hypothesis

• A testable prediction, often implied by a theory.

Iconic Memory

• A momentary sensory memory of visual stimuli; a photographic or picture-image memory lasting no more than a few tenths of a second.

Id

• A reservoir of unconscious psychic energy that, according to Freud, strives to satisfy basic sexual and aggressive drives. The id operates on the pleasure principle, demanding immediate gratification.

Identical Twins

• Twins who develop from a single fertilized egg that splits in two, creating two genetically identical organisms.

Identification

• The process by which, according to Freud, children incorporate their parents' values into their developing superegos.

Identity

• Our sense of self; according to Erikson, the adolescent's task is to solidify a sense of self by testing and integrating various roles.

Illusory Correlation

• The perception of a relationship where none exists.

Imagery

• Mental pictures; a powerful aid to effortful processing, especially when combined with semantic encoding.

Implicit Memory

• Retention independent of conscious recollection. (Nondeclarative or procedural memory)

Imprinting

• The process by which certain animals form strong attachments during an early-life critical period.

Inattentional Blindness

• Failing to see visible objects when our attention is directed elsewhere.

Incentive

• A positive or negative environmental stimulus that motivates behavior.

Independent Variable

• The experimental factor that is manipulated; the variable whose effect is being studied.

Individualism

• Giving priority to one's own goals over group goals and defining one's identity in terms of personal attributes rather than group identifications.

Industrial-Organizational (I/O) Psychology

• The application of psychological concepts and methods to optimizing human behavior in workplaces.

Informational Social Influence

• Influence resulting from one's willingness to accept others' opinions about reality.

Informed Consent

• An ethical principle that research participants be told enough to enable them to choose whether they wish to participate.

Ingroup

• "Us"—people with whom we share a common identity.

Ingroup Bias

• The tendency to favor our own group.

Inner Ear

• The innermost part of the ear, containing the cochlea, semicircular canals, and vestibular sacs.

Insight

• A sudden realization of a problem's solution; contrasts with strategy-based solutions.

Insomnia

• Recurring problems in falling or staying asleep.

Instinct

• A complex behavior that is rigidly patterned throughout a species and is unlearned.

Intellectual Disability

• A condition of limited mental ability, indicated by an intelligence score of 70 or below and difficulty in adapting to the demands of life. Varies from mild to profound.

Intelligence

• Mental quality consisting of the ability to learn from experience, solve problems, and use knowledge to adapt to new situations.

Intelligence Quotient (IQ)

• Defined originally as the ratio of mental age to chronological age multiplied by 100.
• On contemporary intelligence tests, the average performance for a given age is assigned a score of 100.

Intelligence Quotient (IQ) = \frac{Mental Age}{Chronological Age} * 100

Intelligence Test

• A method for assessing an individual's mental aptitudes and comparing them with those of others, using numerical scores.

Intensity

• The amount of energy in a light