Note: the following has been abstracted from the Grolier Encyclopedia.

Psychology

Psychology is the systematic study of human and animal behavior. Psychologists try to understand why living beings act the way they do, how they grow up, how they learn and change, how they differ from one another, and even how they get into trouble or become disturbed. Unlike PSYCHIATRY, which is a medical specialty devoted to the understanding and cure of mental disease, psychology has a broader task, ranging from the laboratory study of simple behavior in animals (insects, worms, rats, and pigeons have been commonly used in psychological experiments) to the complicated behavior of human beings in social groups.

To be sure, some psychologists--clinical psychologists--devote most of their efforts to helping disturbed, troubled, and mentally ill people; clinical psychologists often use techniques much like those employed by psychiatrists. Psychology is, however, far more than a set of therapies for the troubled.

In a sense, psychology can be best understood as a federation of interests: an alliance of scholars, scientists, and practitioners that is held together by a shared commitment to the systematic study of human and animal behavior. Psychologists believe that animal movements and human minds can be examined as carefully and scientifically as astrophysicists study galaxies or as biochemists study nucleic acids. No place exists in modern psychology for phrenology, astrology, or other superstitions about the causes of behavior.

About a century ago psychology became an independent field of study. With its roots in philosophy, physiology, and psychiatry, the relatively new field of psychology has maintained its breadth. It stretches from biological study at one border, through the examination of human beings in groups--which has much in common with sociology and anthropology--out to the edges of clinical psychiatry and general medicine.

Several major dimensions define the ways in which contemporary psychologists differ. One is the animal-human dimension. Some psychologists focus on animals. The study of animals permits better isolation of important causes of behavior and better experimental control. Most psychologists, however, study some aspect of human behavior.

"One-several-many" is another dimension. Psychologists can work with one person (for example, a neurotic in therapy), several people (babies and parents to study emotional communication between them, for instance), or large groups of people (such as the study of mobs or cross-cultural comparisons).

The "species-individual" dimension also separates psychologists. Many investigate what makes each individual unique; other psychologists want to discover the characteristics of people (or animals) as members of a particular species.

Finally, the "basic-applied" distinction, although not a sharp one, refers to the tendency to concentrate either on basic research and teaching in colleges and universities or on applied work in schools, businesses, and clinics. About half of contemporary psychologists are in basic work and half in applied. Interaction can be seen in all fields. For the sake of economy and clarity, however, basic and applied psychology are separated here to give an overview of contemporary psychology.

FIELDS OF BASIC PSYCHOLOGY

Psychology as a Biological Science

Psychology as a Biological Science. Perhaps the oldest and longest thread in the growth of psychology as a research discipline ties psychology to biological study. Physiological and comparative psychology grew primarily from the evolutionary theories of Charles Darwin; learning was added as a major component of psychology near the beginning of the 20th century. These three fields are discussed below.

Physiological Psychology

Applying neuroanatomy and neurophysiology to the study of behavior, physiological psychology asks such questions as: Which structures of the brain and nerves grow and change in animal and human action? What are the neural networks that manage sensory experience? More recently, physiological psychologists have become especially interested in hormonal and biochemical changes in nerves, glands, and muscles--changes that may be closely related to human development, emotion, and learning. Much additional research is necessary before explicit links can be made between DNA and learning French, for example, but physiological psychologists are moving steadily toward a resolution of the ancient question of how the brain relates to behavior.

Comparatie Psychology

Comparative psychology investigates animal behavior. More modest about the lessons of animals for human beings than their 19th-century forerunners, comparative psychologists continue to be interested in animal behavior in its own right and as a potential model for understanding human behavior. Ethology, a subgroup of comparative psychology, studies animals ranging from ducks and rats to baboons, in natural settings, and tries to draw general conclusions about patterns of mating, parental care, and adaptation.

Learning

The study of learning is one of the central themes of psychology, with connections to child psychology, physiological psychology, education, and therapy. Learning psychologists examine simple behavior in animals--for example, pigeons learning which of several keys to peck for a reward. Learning psychologists also study human learning, design procedures and devices for educational application (such as TEACHING MACHINES), and develop programs for modifying problem behavior. In the history of psychology, learning psychologists--especially Ivan PAVLOV, John B. WATSON, Clark HULL, and B. F. SKINNER--have uniformly represented psychology as a science, subject to the same rules of evidence and inference that characterize physics or biology. They have also usually argued for simple and straightforward explanations of behavior and for the efficacy of reward and punishment in the modification of behavior.

Cognitive Psychology

Among the first issues that excited the interest of psychologists in the early decades of the discipline were perception, memory, and language. How do people come to interpret sights and sounds as meaningful objects and events? How do people store evidence about what has happened in order to remember the past? How is speech acquired? These questions are still alive in psychology, and, together with inquiries about imagery and thinking, they make up the broad field called cognitive psychology.

Perception. Studies in perception investigate visual illusions, the recognition of depth and color, and, increasingly, the ways people put information together to make sense out of what they experience. Adult humans are able to move through a rich and complicated world of sensations and impressions; perceptual psychology examines how people group, categorize, and organize all the evidence their senses deliver.

Memory. The workings of the memory are akin to both perception and thinking. Recent research has demonstrated that people have several systems of memory: a short-term memory that holds images of sight and sound just long enough for people to see properly and to hear; a slightly longer-term memory that permits, for example, the storage of telephone numbers long enough to get them dialed; and a long-term memory that seems to hold the past almost indefinitely. Psychologists who study memory tackle the mechanisms of memory encoding and retrieval in all three forms.

Psycholinguistics. A significant segment of cognitive psychology, psycholinguistics stretches from formal linguistics to social psychology.

Thinking. Cognitive psychologists study thinking from several points of view. Some investigators carry out experiments on problem solving, the making of inferences, and the use of analogies in thought; others examine real-life thought in games such as chess or in the making of complex decisions. An exciting recent development in the study of thinking has been the attempt to mimic or simulate human thought with computer programs.

Imagery. After long neglect, imagery is a bright field in contemporary psychology. Researchers are studying imagery and creativity, fantasy, dreams--even the place of television in children's imagination.

Emotion. Why are some people calm, effective, and surefooted when others are jumpy and scattered? What makes people courageous, sad, angry, or mean? The answers proposed to such questions have been various. Some psychologists are interested in the genetics of individual differences in emotion and personality; other researchers delve into the nature of emotion itself.

Motivation. Investigators work on the sources of action--motivation--to determine how much behavior can be accounted for by simple drives such as hunger, sex, or pain, and how much depends on complex social motivation such as the need to achieve or the desire to outpoint a rival.

Personality. No part of psychology is more difficult and contentious than the study of personality. In recent years the very idea of stable personal characteristics has come under attack; some researchers have maintained that people behave more according to the requirements of the immediate social environment than according to persistent traits of personality such as good humor or irritability. Many tests of personality exist.

Abnormal Psychology

The study of abnormal behavior is a branch of personality psychology, and it is perhaps the kind of psychology that most often finds its way into the popular press, television, and imagination. Abnormal psychology includes the diagnosis of mental malfunction, often with tests of assorted kinds; the systematic description or taxonomy of abnormal behavior; and the study of the effectiveness of psychological and pharmacological (drug) therapies.

Social Psychology

When a human being enters into an exchange with another human being, this interaction is a problem in social psychology. Recent research has indicated that most people will behave in extraordinary ways--for example, they will be willing to injure an innocent person if someone in authority tells them that such behavior is in order.

Developmental Psychology

The "general practitioners" of psychology, developmental psychologists study all aspects of behavior as it changes from birth to old age. The work of developmental psychologists borders on the applied fields of educational and school psychology covered below.

FIELDS OF APPLIED PSYCHOLOGY

The practical, important, and demanding task of applied psychologists is to combine their own experience with their knowledge of basic psychology in order to solve everyday human problems. Applied psychologists may help a schoolchild to learn, an assembly line to move smoothly, a group of executives to reach a wise decision, an abusing parent to stop beating a child, or a patient in an institution to experience some relief from anxiety. The tasks are as diverse as those of basic psychology, but they are different from those of basic psychology in at least two related ways. First, the problems faced by the applied psychologist cannot be postponed until new experiments or new theories are developed; today's problems in the classroom or clinic must be addressed today. Second, applied psychologists rarely can choose what human puzzle they will try to solve.

Educational Psychology

Educational psychologists usually work with teachers and with schoolchildren in an attempt to devise effective teaching procedures and to design classroom activities that lead to learning; they also counsel students about curriculum and personal problems.

Industrial Psychology

Industrial psychology brings together information about perception, management, and social organization to make industries and businesses operate more efficiently and humanely. Some industrial psychologists are specialists in organizational behavior--how best to get people working together--and others concentrate on job satisfaction, public relations, incentives for work, and aspects of advertising.

Psychometrics

This field lies between basic and applied psychology. Psychometricians (the term means "mind-measurer") invent and refine tests of competence and aptitude; give tests of various kinds to discover human talent, potentiality, or the need for special training; and examine verbal skills, aptitude for new jobs, personality characteristics, or the likelihood of emotional disturbance.

Clinical Psychology

The largest field of applied psychology, clinical psychology diagnoses mental distress and helps psychologically disturbed people find a more balanced way of living. Clinical psychology has, of course, affinities to psychiatry. Much of the therapy of clinical psychologists is carried out in person-to-person meetings, but, increasingly over the years, clinical psychologists have worked with larger groups, from two-person groups such as spouses or parent and child to a dozen or more residents of an institution.

METHODS PSYCHOLOGISTS USE

Just as the research and practical interests of psychologists are diverse, so are their methods. Some applied procedures--tests or therapy methods--have been mentioned earlier. The present section will focus on research methods.

Random-Assignment Experiment

The surest and most reliable way to find out the sources of behavior is to conduct an experiment. Two (or more) groups of subjects are selected randomly, so that there is no bias in their selection, and then each group is given a different experience. For example, one group of young sparrows is raised with adult sparrows, a second group with adult wrens. In this way one may learn something about transmission of species-specific birdsong. The random-assignment experiment permits strong inferences from its results. Its use is limited, however, by the fact that some important human behavior cannot be subjected to experimental study.

Contrasting Natural Groups

Since the mid-19th century a major method of psychological investigation has been to observe naturally occurring groups that differ in some important way. Often the comparison of natural groups is made more informative by giving the groups a planned common experience. Psychologists now know, for example, that mentally retarded children in institutions will not work as hard on their own in a laboratory task as mentally retarded children (with the same test scores) raised at home.

A problem persists in comparing natural groups: the differences observed between groups may be related to the defining characteristic (such as IQ), but they may also be related to some other correlated factor that defines the groups. Some psychologists feel that serious misinformation has been written about racial differences in behavior because inadequate attention was sometimes given to factors other than ancestry--such as education or economic status--that separates minority groups in modern society.

Field Observation

Some animal and human action can be studied in its ordinary everyday setting. A famous group of European ethologists including Konrad LORENZ made many discoveries about the mating, parental, and fighting behavior of birds and small mammals. A number of studies have monitored a small group of children over the first years of their lives (a few for 40 years or longer) in order to understand the development of personality, intelligence-test performance, or other aspects of individual difference. Such longitudinal studies of development combine field observations in hospital, home, and school with laboratory tasks and with intricate batteries of tests.

The Case Study

Less widely used in research than either the experiment, comparison study, or field observation, the case study has been a significant source of new ideas for psychologists. A case study is the intensive study of a single person or of a few persons; it has been most influential in three fields of psychology--abnormal psychology, cognitive development, and language.

Sigmund FREUD's reconstructions of life histories stand as models for the application of the case study to abnormal psychology: he built an explanation of his patient's disorders from interviews, free association, and the analysis of dreams. Jean PIAGET has used the case study in a different, but equally productive, way: he studied his three children over the first three years of their lives to outline the course of early cognitive development. In language studies the case study has always been important. Case studies are, however, limited in their generality. Who can say for sure in what ways the person under study is typical or eccentric? Nevertheless, case studies remain a basic first step in psychologists' exploration of the human mind.