Any human endeavor can involve creativity and is not limited to just the arts. Numerous theories of creativity were proposed by 20th-century psychologists, educators and other social scientists. Howard Gruber, who worked to understand creativity by studying the lives of famous innovators, found broad common characteristics:1) they engaged in a variety of activities within their chosen fields; 2) t…
Although this term is used in a variety of contexts, the term is most closely associated with ethology, the study of animal behavior in its natural environment from the perspective of evolutionary adaptation. The critical period plays an important role in the concept of imprinting, first used by Konrad Lorenz in connection with the earliest process of social attachment in young animals. (However, …
A cross-sectional study is a research method where data are collected at the same time from people in different age categories. It contrasts with the method, known as longitudinal study, where the same group of subjects is studied over time. One weakness, or confounding variable, of the cross-sectional study is that its subjects, in addition to being different ages, are also born in different year…
A cult is a structured group, most of whose members demonstrate unquestioned loyalty to a dynamic leader. The cult leader governs most, if not all, aspects of the lives of his or her followers, often insisting that they break all ties with the world outside of the cult. Such groups are usually thought of in terms of religion, although other types of cults can and do exist. The proliferation of rel…
Daydreams are a form of imagination. In daydreams, the person forms a mental image of a past experience or of a situation that he or she has never actually experienced. Some psychologists use the acronym TUIT (Task-Unrelated Images and Thoughts) to describe episodes of daydreaming. A daydream may be triggered by a situation, a memory, or a sensory input (sight, taste, smell, sound, touch). The day…
The concept of the defense mechanism originated with Sigmund Freud (1856-1939) and was later elaborated by other psychodynamically oriented theorists, notably his daughter Anna Freud (1895-1982). Defense mechanisms allow negative feelings to be lessened without an alteration of the situation that is producing them, often by distorting the reality of that situation in some way. While they can help …
Almost everyone, everyday, practices delay of gratification—whether deciding to skip dessert in order to lose weight or give up smoking in order to live longer. The ability to delay gratification is often a sign of emotional and social maturity. Young children, for example, find it more difficult to delay gratification than older children. When kindergartners in one study were offered a cho…
Dementia generally occurs in the elderly, although it can appear at any age. Several substantial studies have been done to determine its prevalence, and in 1991 a major study was conducted which found that dementia occurred in just over 1 percent of the population aged 65 to 74; in approximately 4 percent in ages 75 to 84; and more than doubling to 10.14 percent in persons 85 and over. Other studi…
Dendrites are one of two types of short, threadlike fibers that extend from the cell body of a nerve cell, or neuron. The other type are called axons. Dendrites receive electrochemical signals, which are known as postsynaptic potentials, from the axons of other neurons, and the information contained in these signals is fired across a synaptic gap or cleft about 0.02 microns or about 8 millionths o…
As the transmitter of inherited characteristics, deoxyribonucleic acid (DNA) replicates itself exactly and determines the structure of new organisms, which it does by governing the structure of their proteins. The Swiss researcher Friedrich Miescher first discovered DNA in 1869 when he extracted a substance (which he called nuclein) containing nitrogen and phosphorus from cell nuclei. The question…
When conducting research, a psychologist typically takes two or more similar groups of people or animals and exposes them to different treatments or situations. Then the researcher monitors a behavior of interest to see whether that behavior differs from one group to the next. This measurement is the dependent variable. A single experiment may involve more than one dependent variable. When specify…
Depression may signify a mood, a symptom, or a syndrome. As a mood, it refers to temporary feelings of sadness, despair, and discouragement. As a symptom, it refers to these feelings when they persist and are associated with such problems as decreased pleasure, hopelessness, guilt, and disrupted sleeping and eating patterns. The entire syndrome is also referred to collectively as a depression or d…
We can determine the relative distance of objects in two different ways. One uses cues involving only one eye; the second requires two eyes. When something is far from us, we rely on monocular cues, those that require the use of only one eye. For closer objects, we use both monocular cues and binocular cues, those that necessitate both eyes. The ability to perceive depth seems to exist early in li…
Since ancient times, the origins of human behavior have been attributed to hidden or mystical forces. The Greek philosopher Democritus speculated, for example, that objects in our world consist of atoms; included among these "objects" was the soul, which was made of finer, smoother, and more spherical atoms than other physical objects. He rejected the concept of free will and claimed…
The American Psychiatric Association publishes the Diagnostic and Statistical Manual of Mental Disorders, widely referred to as DSM-IV, a reference work designed to provide guidelines for psychologists and others to use in the diagnosis and classification of mental disorders. The latest edition, DSM-IV, serves as a reference to psychiatrists, other physicians and mental health professionals, psych…
In the United States, the term disability is legally defined in the Rehabilitation Act (PL 93-112; 29 U.S.C. 794) Amendments of 1974 and the Americans with Disabilities Act (PL 101-336; 42 U.S.C. 12101) of 1990 as a physical or mental impairment that substantially limits one or more of the major life activities of an individual. Disabilities may be caused by congenital, traumatic, pathological, or…
Persons suffering from dissociative identity disorder (DID) adopt one or more distinct identities which co-exist within one individual. Each personality is distinct from the other in specific ways. For instance, tone of voice and mannerisms will be distinct, as well as posture, vocabulary, and everything else we normally think of as marking a personality. There are cases in which a person will hav…
The concept of divergent thinking was developed in the 1950s by psychologist J.P. Guilford, who saw it as a major component of creativity and associated it with four main characteristics. The characteristics were fluency (the ability to rapidly produce a large number of ideas or solutions to a problem); flexibility (the capacity to consider a variety of approaches to a problem simultaneously); ori…
The divorce rate in the United States began rising in the 1960s and continued for more than two decades, with a decline in the trend in the 1990s. In 1960 the divorce rate per 1,000 population was 2.6. By 1980, the rate had reached 5.2 and in 1990 dropped to 4.7. This decline continued to 4.3 in 1997. Based on current societal trends, researchers project that 40 to 50 percent of all first marriage…
Dreams defy the laws of physics, the principles of logic, and personal morality, and may reflect fears, frustrations, and personal desires. Often occurring in story-form with the dreamer as participant or observer, dreams usually involve several characters, motion, and may include sensations of taste, smell, hearing, or pain. The content of dreams clearly reflects daytime activities, even though t…
Many psychologists believed that all motivation depended upon the pleasure experienced when basic needs are met. A person who is hungry, for instance, eats in order to reduce the tension that hunger produces. All human behavior could be attributed to the pleasure gained when these drive-induced tensions were reduced. Drive reduction theory lost favor over the years because it failed to explain hum…
Psychoactive drugs alter behavior, thought, or emotions by changing biochemical reactions in the nervous system. They can be addictive (habit-forming), and they can be legal or illegal. Drug abuse is the self-administration of drugs in ways that depart from medical or social norms, and it can lead to psychological or physical dependence. Physical dependence, or addiction, which can occur together …
Although this term is used casually in popular culture, health care professionals define dysfunctional family as one where the relationships among family members are not conducive to emotional and physical health. Sexual or physical abuse, alcohol and drug addictions, delinquency and behavior problems, eating disorders, and extreme aggression are some conditions commonly associated with dysfunctio…
Dyslexia is a specific learning disability characterized by a significant disparity between an individual's general intelligence and his or her language skills, usually reflected in school performance. Estimates of people with dyslexia range from 2% to the National Institutes of Health figure of 15% of the U.S. population. It is a complicated disorder with no identifiable cause or cure, yet…
An effector acts in special ways in response to a nerve impulse. In humans, effectors may either be muscles, which contract in response to neural stimuli, or glands, which produce secretions. The muscles are generally divided into two groupings: somatic effectors, which are the body's striated muscles (such as those found in the arm and back), and autonomic effectors, which are smooth muscl…
Sigmund Freud believed that human personality has three components: the id, the ego and the superego. In his scheme, the id urges immediate action on such basic needs as eating, drinking, and eliminating wastes without regard to consequences. The ego is that portion of the personality that imposes realistic limitations on such behavior. It decides whether id-motivated behavior is appropriate, give…
In contrast to moods, which are generally longer-lasting, emotions are transitory, with relatively well-defined beginnings and endings. They also have valence, meaning that they are either positive or negative. Subjectively, emotions are experienced as passive phenomena. Even though it is possible to exert a measure of control over one's emotions, they are not initiated—they happen t…
Emotional intelligence (EI) is sometimes referred to as emotional quotient or emotional literacy. Individuals with emotional intelligence are able to relate to others with compassion and empathy, have well-developed social skills, and use this emotional awareness to direct their actions and behavior. The term was coined in 1990 by psychologists John Mayer and Peter Salovey. In 1995, psychologist/j…
While most forms of psychotherapy require some degree of empathy on the part of the counselor or therapist, the client-centered therapy pioneered by Carl Rogers places particular emphasis on this quality as part of the therapeutic experience. Instead of looking at the client from outside (external frame of reference), the client-centered therapist attempts to see things as they actually look to th…
Psychologists prefer to learn about behavior through direct observation or experience. This approach reflects what is called empiricism. Psychologists are well-known for creating experiments, conducting interviews and using surveys, and carrying out case studies. The common feature of these approaches is that psychologists wait until observations are made before they draw any conclusions about the…
Encounter groups are formed, usually under the guidance and leadership of a psychologists or therapist, to provide an environment for intensive interaction. In general, because the therapy takes place in a group setting, one of the goals of the encounter group is to improve the participants' interpersonal skills. A typical encounter group may consist of fewer that ten persons, one of whom i…
The endocrine glands—the pineal, pituitary, thyroid, parathyroids, thymus, adrenals, pancreas and gonads (ovaries or testes)—comprise the endocrine system. The hypothalamus, the gland in the brain which serves as the command center, operates the endocrine system through the pituitary, a pea-sized gland located under it, which directs the work of all the other glands. The thyroid, a g…
The relative importance of heredity and environment in shaping human lives—nature versus nurture— has long been a topic of debate taken up by thinkers as diverse as John Locke, Charles Darwin, and Sigmund Freud, and forms part of current policy debates in areas Cross-section of a human adrenal gland, one of the endocrine glands. (Photo by Martin M. Rotker. Phototake NYC. Reproduc…
Epilepsy, from the Greek word for seizure, is a recurrent demonstration of a brain malfunction. The outward signs of epilepsy may range from only a slight smacking of the lips or staring into space to a generalized convulsion. It is a condition that can affect anyone of any age, sex, or race. The number of people with epilepsy is not known. Some authorities say that up to 0.5% of the population ar…
The equilibrium sense, generally associated with balance, provides feedback about the positions and movements of our heads and bodies in space. The other system—the kinesthetic sense—tells us about the orientation of different parts of our bodies in relation to each other. While the kinesthetic information needed by the brain comes from joints and muscle fibers throughout the body, t…
Ethics are rules for behavior, based on beliefs about how things should be. Ethical statements involve: 1) assumptions about humans and their capacities; 2) logical rules extending from these assumptions; and 3) notions of what is good and desirable. Ethical systems (sets of rules for acceptable behavior) concern the "shoulds" and "should nots" of life, the principles a…
The adjective ethnic is derived from the Greek noun ethnos, which means race, people, nation, and tribe. Although the modern term has a narrower connotation, denoting primarily people, vestiges of the older, more inclusive meaning still remain, particularly in types of discourse where the concepts of race and nationality are used interchangeably. Matters get even more complicated when the concept …
Ethnocentrism is a general belief that the ethnic group with which an individual is identified is superior to all other ethnic groups. Consequently, the individual persistently uses membership in the ethnic group as a primary criterion in the formation of relationships with others, and in evaluating or making judgments concerning other individuals. The term sociocentrism is sometimes used as a syn…
As Charles Darwin's ideas on evolutionary theory gained acceptance in the late 1800s, the public's faith in science as a source for social remedies increased in popularity, and scientists have looked for ways to "improve" humanity. British scientist Francis Galton introduced the ideas that led to a scientific approach to eugenics, including the concept of "positi…
In classical/respondent conditioning, the learned response disappears when the association between conditioned and unconditioned stimuli is eliminated. For example, when a conditioned stimulus (a light) is presented with an unconditioned stimulus (meat), a dog may be trained to salivate in response to the conditioned stimulus. If the unconditioned stimulus does not appear at least some of the time…
Extroverts are people who are often leaders, work well in groups, and prefer being with others to being alone. Other personality traits often associated with extroversion include optimism, risk taking, and love of excitement and change. People who are extroverts prefer having company and tend to have many friends. Extroversion is generally defined in comparison to its opposite, introversion, which…
The majority of persons suffering from mental retardation fall into the category of familial retardation rather than that of clinical retardation, which usually has neurological or other organic causes. Persons with familial retardation typically have IQs ranging from 55-69 and show no signs of physical disability. Environmental causes thought to contribute to familial retardation include the qual…
A fantasy is inspired by imagination characterized by mental images that do not necessarily have any relationship to reality. In psychoanalysis, fantasy is regarded as a defense mechanism. For example, after being reprimanded by a supervisor, a worker may fantasize about taking over the company and firing the supervisor. Similarly, a child may fantasize about running away from home in retaliation …
Fear is one of the primary emotions, together with joy, anger, and grief. Fear generally refers to feelings elicited by tangible, realistic dangers, as opposed to anxiety, which often arises out of proportion to the actual threat or danger involved. Fear may be provoked by exposure to traumatic situations, observations of other people exhibiting fear, or the receipt of frightening information. Rep…
The effects of heavy maternal alcohol use during pregnancy were first described as fetal alcohol syndrome (FAS) in the United States in 1973. An estimated one to three babies of every thousand births in the United States Facial features of fetal alcohol syndrome. has FAS, making FAS the leading cause of mental retardation. It is also one of the few preventable causes of mental retardation a…
A person's ability to separate an object from its surrounding visual field is referred to as figure-ground perception. The object that a person focuses on is called the figure; everything else is referred to as background, or simply ground. Psychologists have created different kinds of stimuli in order to study how people separate figure from ground. In some cases, these stimuli involve sim…
Sigmund Freud theorized that the developmental stages of infancy and early childhood chart our lives in ways that are difficult to change. He believed that most adult neuroses could be attributed to a fixation developed during one of these stages of early life. Freud was especially concerned about how these stages were related to sexual development in later life, and in this he was, and continues …
Humans can detect sound waves with frequencies that vary from approximately 20 to 20,000 Hz. Probably of greatest interest to psychologists are the frequencies around 500-2,000 Hz, the range in which sounds important to speech typically occur. Humans are most responsive to sounds between 1,000 and 5,000 Hz, and are not likely to hear very low or very high frequencies unless they are fairly intense…
When data is presented in a frequency distribution, the objective is to show the number of times a particular value or range of values occurs. Common forms of presentation of frequency distribution include the frequency polygon, the bar graph, and the frequency curve, which associate a number (the frequency) with each range, class, or category of data. A grouped frequency distribution is a kind of…
Research has shown that people who have friends tend to have better physical health and report a better sense of psychological well-being than those with weak or no network of friends. Although some people may know a lot of people, they have a more select group of friends and an even smaller number of "best" friends. Friends provide support in three main ways: emotional, cognitive gu…
Fugues are classified as a dissociative disorder, a syndrome in which an individual experiences a disruption in memory, consciousness, and/or identity. This may last anywhere from less than a day to several months, and is sometimes, but not always, brought on by severe stress or trauma. Dissociative fugue (formerly termed psychogenic fugue) is usually triggered by traumatic and stressful events, s…
In solving problems, humans try to focus on the best strategy to reach the goal. Sometimes problems are more difficult to solve than they need to be because the available solutions are not clear or obvious. That is, humans form mental sets, ways of viewing the potential solutions, that actually hinder progress. When people develop functional fixedness, they recognize tools only for their obvious f…
The goal of the first psychologists was to determine the structure of consciousness just as chemists had found the structure of chemicals. Thus, the school of psychology associated with this approach earned the name structuralism. This perspective began in Germany in the laboratory of Wilhelm Wundt (1832-1920). Before long, however, psychologists suggested that psychology should not concern itself…
The Commission on the Review of the National Policy Toward Gambling reported that 61% of the U.S. population engaged in some form of gambling. The group also estimated that there were 1.1 million compulsive gamblers in the United States. While for many people gambling is a form of harmless recreation, for others it is an uncontrollable and all-consuming pursuit, often eclipsing everything else in …
A gang is a group of people whose members recognize themselves as a distinct entity and are recognized as such by their community. Their involvement in antisocial, rebellious, and illegal activities draws a negative response from the community and from law enforcement officials. Other characteristics of gangs include a recognized leader; formal membership with initiation requirements and rules for…
Gender bias, and its corollary, gender equity, describe the comparison of opportunities and treatment available to males with those available to females. Today, gender bias is observed and discussed in societies and cultures worldwide. Parents and teachers of young people are especially concerned with unequal treatment of boys and girls, particularly the effect these differences have on child deve…
Influenced by a combination of biological and sociological factors, gender identity emerges by the age of two or three and is reinforced at puberty. Once established, it is generally fixed for life. Aside from sex differences, other biological contrasts between males and females are already evident in childhood. Girls mature faster than boys, are physically healthier, and are more advanced in deve…
There are differences in intellectual attainment among people. Some people make strides in learning and creativity that are well beyond what would normally be expected and are called geniuses. Although definitions of genius, or giftedness, are inevitably culture-bound and subjective, psychologists are trying to determine what factors might contribute to its emergence. In a 1981 study, William Fowl…
The psychologists in Germany who proposed the Gestalt principles of organization developed theories and research focusing on the effects of holistic patterns or configurations (the rough meaning of the German term Gestalt) on perception. Much of their work emphasized the concept that the whole affects the way in which parts are perceived: "the whole is more than the sum of its parts."…
Intellectual giftedness is generally indicated by an IQ of least 125 or 130. People who are extremely creative are also considered gifted, although their giftedness can be hard to identify by academic performance or standardized tests. Giftedness has been defined not only in terms of specific talents and academic abilities, but also by general intellectual characteristics (including curiosity, mot…
Granville Stanley Hall played a decisive role in the organization of American psychology. He invited Sigmund Freud and Carl Jung to America, thus contributing to the diffusion of psychoanalysis. Above all, he gave a crucial impetus to the study of the child and the life cycle (his last psychological book dealt with senescence, the process of becoming old). Hall stressed the social relevance of emp…
Motor skills are deliberate and controlled movements requiring both muscle development and maturation of the central nervous system. In addition, the skeletal system must be strong enough to support the movement and weight involved in any new activity. Once these conditions are met, children learn new physical skills by practicing them until each skill is mastered. Gross motor skills, like fine mo…
Guilt is both a cognitive and an emotional experience that occurs when a person realizes that he or she has violated a moral standard and is responsible for that violation. A guilty conscience results from thoughts that we have not lived up to our ideal self. Guilt feelings may also inhibit us from falling short of our ideal again in the future. Individual guilt is an inner reflection on personal …
Halfway houses are typically staffed by therapists, counselors, social workers, other mental healthcare professionals, or lay-people with a background in the treatment area. Time spent both in and away from the house is highly structured. Residents are allowed to leave the facility for work and school, but are assigned housekeeping or other tasks that contribute to the house and its residents duri…
Although hallucinations are false perceptions, they carry the force of reality and are a definitive sign of mental illness. Hallucinations may be caused by organic deterioration or functional disorders, and can occur in normal people while asleep or awake, or as a result of sensory deprivation. Generally not positive experiences, hallucinations are often described as frightening and distressing. A…
Hallucinogens, or psychedelics, are substances that alter users' thought processes or moods to the extent that they perceive objects or experience sensations that in fact have no basis in reality. Many natural and some synthetic substances have the ability to bring about hallucinations. In fact, because of the ready market for such chemicals, they are manufactured in illegal chemical labora…
Halo effect is a phenomenon that occurs when one is influenced by a person's strengths, weaknesses, physical appearance, behavior, or any other single factor. The halo effect is most often apparent in situations where one person is responsible for evaluating or assessing another in some way. Examples of such situations include assessment of applicants for jobs, scholarships, or awards; desi…
The term handedness describes a characteristic form of specialization whereby a person by preference uses one hand for clearly identified activities, such as writing. For example, a person who uses his or her right hand for activities requiring skill and coordination (e.g., writing, drawing, cutting) is defined as right-handed. Roughly 90% of humans are right-handed. Because left-handed people who…
The ear, the receptive organ for hearing, has three major parts: the outer, middle, and inner ear. The pinna or outer ear—the part of the ear attached to the head, funnels sound waves through the outer ear. The sound waves pass down the auditory canal to the middle ear, where they strike the tympanic membrane, or eardrum, causing it to vibrate. These vibrations are picked up by three small …
There are certain traits that parents pass on to their children, including eye color, hair color, height, and other physical characteristics. The coding for these traits are contained inside DNA molecules that are present within all human cells. Since the discovery of DNA by James Watson (1928-) in the 1950s, the science of genetics has focused on the study of DNA and the ways in which physical tr…
The sex drive, or sexual desire, is an unlearned, powerful drive that humans share with other animal species. Heterosexuals experience sexual desire in relation to members of the opposite sex. This contrasts with homosexuals, where the object of sexual desire is a member of one's own sex. Most researchers believe that children begin to notice physical differences between males and females b…
For most of history, open discussions about homo-sexuality—sexual attraction to people of one's own gender—have been taboo. Men and women with a homosexual orientation are referred to as gay, while the term lesbian refers to women only. Homosexuality was classified as a mental disorder until 1973, when the American Psychiatric Association removed "homosexuality" …
Hormones are biochemical messengers that regulate physiological events in living organisms. More than 100 hormones have been identified in humans. Hormones are secreted by endocrine (ductless) glands such as the hypothalamus, the pituitary gland, the pineal gland, the thyroid, the parathyroid, the thymus, the adrenals, the pancreas, the ovaries, and the testes. Hormones are secreted directly into …
Hostility is a strong impulse inspired by feelings of anger or resentment. Though hostile impulses are normal, and everyone has them from time to time (for example, when frustrated, offended, or deprived of something), a hostile person feels those impulses regularly. She or he is always ready to take offense or feel frustrated in some way. This is often described as "having a chip on one&#x…
William James, an early proponent of human potential and altered states of consciousness, is considered a forerunner of the human potential movement. However, modern interest in human potential can be traced most directly to the humanistic psychological approach of such figures as Carl Rogers and Abraham Maslow in the 1950s. Humanistic psychology was sometimes referred to as the Third Force becaus…
Sigmund Freud considered humor an outlet for discharging pent up psychic energy and diminishing the importance of potentially damaging events. Since the 1970s, research on humor has shifted from a Freudian focus to an emphasis on its cognitive dimensions, including investigations involving information-processing theory. Humor has been found to depend on the disparity between expectations and perce…
Practiced since ancient times, hypnosis or hypnotism remains difficult to define accurately and completely. Although the word hypnosis comes from the Greek word hypnos, for sleep, hypnosis is actually an intense state of concentration. There are three degrees of hypnosis. Under light hypnosis, the subject becomes sleepy and follows simple directions; under deep hypnosis, the person experiences dul…
The hypothalamus, which together with the thalamus makes up the section of the forebrain called the diencephalon, is involved in such aspects of behavior as motivation, emotion, eating, drinking, and sexuality. Lying under the thalamus, the hypothalamus weighs only a fraction of an ounce and is a little larger than the tip of the thumb. It is connected to the autonomic nervous system, and controls…
When psychologists engage in research, they generate specific questions called hypotheses. Research hypotheses are informed speculations about the likely results of a project. In a typical research design, researchers might want to know whether people in two groups differ in their behavior. For example, psychologists have asked whether the amount that we can remember increases if we can find …