The concept of gender constancy, influenced by the cognitive development theory of Jean Piaget, was introduced by Lawrence Kohlberg (1927-1987). Addressing the formation of gender identity in terms of cognitive development, Kohlberg advanced the idea that the development of sex roles depends in large part on a child's understanding that gender remains constant throughout a person's l…
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…
Researchers have suggested that both early socialization and prenatal hormones may play an important role in the development of transsexuality. It is estimated that about 1 in 20,000 males and 1 in 50,000 females are transsexuals. Gender identity disorder generally begin to manifest between the ages of two and four, in which a child displays a preference for the clothing and typical activities of …
The first stage of the general adaptation syndrome is alarm reaction, and includes the shock phase and the countershock phase. In the shock phase, there are significant changes in several organic systems. For example, body temperature and blood pressure are lowered, and muscle tone is decreased. In the countershock phase, there is a defensive response to these changes, including an increased produ…
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…
Arnold Gesell was born in Alma, Wisconsin, and received his bachelor's degree from the University of Wisconsin. In 1906, he earned his Ph.D. from Clark University, where he was motivated to specialize in child development by studying with the prominent American psychologist G. Stanley Hall (1844-1924). Gesell received his M.D. from Yale University in 1915. After briefly holding a Arnold…
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."…
The Gestaltists were at odds with the popular school of psychology of the day, known as structuralism, whose proponents believed that the mind consists of units or elements and could be understood by mapping and studying them in combination. The Gestalt psychologists believed that mental experience was dependent not on a simple combination of elements but on the organization and patterning of expe…
Gibson was born Eleanor Jack in Peoria, Illinois, into a successful Presbyterian family on December 7,1910. Her parents were William A. and Isabel (Grier) Jack. She married fellow psychologist James J. Gibson on September 17, 1932. They had two children, James J. and Jean Grier. Due to prevailing attitudes discouraging females— even gifted ones—from pursuing an education, young Elean…
James Jerome Gibson proposed a theory of vision that was a first of its kind; he suggested that visual perception was the direct detection of environmental invariances, and that visual perception did not require inference or information processing. Gibson was born in 1904 in McConnelsville, Ohio. He started his undergraduate career at Northwestern University. He transferred to Princeton University…
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…
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…
Group therapy has numerous advantages over individual therapy. The therapist's knowledge about the clients offers an added dimension through the opportunity of observing them interact with each other. Clients are helped by listening to others discuss their problems (including problems more severe than theirs) and by realizing that they are not alone. They also gain hope by watching the prog…
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 …
Edwin Guthrie, born Jan. 9, 1886, in Lincoln, Nebraska, was one of five children. His mother was a schoolteacher, and his father a store manager. He received a bachelor's and a master's degree from the University of Nebraska, specializing in mathematics, philosophy, and psychology. He entered the University of Pennsylvania as a Harrison fellow, receiving his doctorate in 1912. His ed…
Jay Haley is an American psychologist recognized as one of the founders of family therapy. Haley was a cofounder of the Family Therapy Institute in Washington, D.C., and he created the publication Family Process. His contributions to the field of therapy include the development of strategic and humanistic processes. Haley was born on July 19, 1923, in Midwest, Wyoming, to Andrew J. and Mary (Snedd…
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…
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…
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…
Hand-eye coordination begins developing in infancy. Although it is an instinctive developmental achievement that cannot be taught, parents can hasten its progress by providing their children with stimulating toys and other objects that will encourage them to practice reaching out for things and grasping them. Until the age of eight weeks, infants are too nearsighted to see objects at distances far…
Experimental and comparative psychologist Harry Harlow is best known for his work on the importance of maternal contact in the growth and social development of infants. Working with infant monkeys and surrogate mothers made of terrycloth or wire, Harlow concluded that extended social deprivation in the early years of life can severely disrupt later social and sexual behavior. Harlow also conducted…
Health psychology is a diverse area with a variety of emphases. Medical psychology focuses on the clinical treatment of patients with physical illnesses, offering practical advice people can use in order to improve their health. While there is special emphasis on psychosomatic disorders—those that have traditionally been most closely related to psychological factors—the current trend…
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 …
The difference between the way a young brain and an older brain processes information was the focus of Donald Hebb's research during a career that spanned nearly half a century. Hebb was fascinated by the way people learned and the way they retained information. His research opened many doors in the field of behavioral science and made him one of the most influential behaviorists in twentie…
How we interpret our own behavior, as well as that of others, formed the basis for Fritz Heider's work during a career that lasted more than 60 years. Heider explored the nature of interpersonal relations, and his work culminated in the 1958 book The Psychology of Interpersonal Relations. Heider espoused the concept of what he called "common-sense" or "naïve�…
Hermann Helmholtz was one of the few scientists to master two disciplines: medicine and physics. He conducted breakthrough research on the nervous system, as well as the functions of the eye and ear. In physics, he is recognized (along with two other scientists) as the author of the concept of conservation of energy. Helmholtz was born into a poor but scholarly family; his father was an instructor…
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…