Applied Psychology

APPLIED PSYCHOLOGY is that branch of technical service in which the facts and methods of the science of. psy chology are applied to the practical affairs of life. Its boundary lines are vague because it merges imperceptibly into the realm of the pure science of psychology, and especially because the range of possible and actual applications is so extensive. In fact, just as everyone considers himself somewhat of a psychologist, so everyone considers himself somewhat of an applied psycholo gist. For these reasons applied psychology has suffered probably more than other applied sciences from the practices of pretenders and charlatans. The popular conception formed from these con tacts is liable to be cheap and erroneous.

History of Applied Psychology.

The very beginnings of applied psychology are discoverable in the work of Charles Dar win, who, in the realm of organic life, sought out variations from individual to individual and from species to species, and em phasized the importance of these variations. Francis Galton extended the search for variation into the realm of mental life (Inquiries into Human Faculty, 1883), and found individual differences as interesting and as significant as those found by Darwin in physical forms and behaviour. The earliest differences pointed out by Galton had some practical bearing, although it remained for Cattell, Binet and their followers to seek and measure differences in human traits which have a more immediate practical application, such as the differences in intelligence, re action time, judgment, etc.

The first clearly formed applications of psychology arose with the recognition that differences among individuals and among groups meant differences in adjustment to situations in everyday life, and that improvements in adjustment must come either through a control of environmental influences or through a modi fication of the individual or the group. Experimental laboratory methods were applied directly to the measurement of the sensory capacities, memory, attention and fatigue of school children in the field of education. As the inadequacies and limitations. of these purely scientific procedures revealed themselves in the practical setting, methods were devised to meet practical needs more directly. Foremost among the pioneers were Binet and Simon, who developed tests for the measurement of intelligence by departing from traditional laboratory technique and building tests out of the experiences of the everyday life of the child (The Development of Intelligence in Children, 1905) ; and Cattell, who originated the order of merit method for the measurement of mental products (The Psychological Researches of James McKeen Cattell, 1914). Credit should be given also to the so called efficiency engineers who analysed industrial tasks and measured the efficiency of different individuals to perform them. They have contributed largely to the development of applied psychology by their attitude toward practical problems.

The Role of Measurement in Applied Psychology.—The most outstanding characteristic of applied psychology is the part played by measurement, which takes two forms: (1) The tests or instruments for the measurement of individual, group, class, sex and race differences in capacity and achievement. (2) Statis tical methods needed for the standardization and validation of the tests and for the analysis and synthesis of the variable products yielded by the tests. The construction of tests has become a highly technical task, and their proper administration and interpretation require special psychological training. The statistical methods of treating biological data have been modified and developed (see the works of Karl Pearson, Charles Spearman and T. L. Kelley) to meet the special requirements for the measurement of general tendencies of behaviour and their inter-relationships.

Divisions of Applied Psychology.

Certain arbitrary, but well-recognized divisions of the field of applied psychology have developed through the demands of practical life and through the expression of interests of investigators. This classification is neither logical nor complete, and will be reconstructed and ex panded as the number of applied psychologists increases and as research data accumulate. The major divisions are Educational Psychology, Vocational Psychology, Industrial Psychology, Busi ness Psychology, Legal Psychology and Medical Psychology. In addition to these there are other less well defined or less active divisions, such as the psychology of religion and the psychology of aesthetics. Then, there are the more highly specialized fields which do not readily fall into any of the above major or minor classes, such as the psychology of music, the psychology of athletics, the psychology of play, military psychology, the psy chology of the deaf, the blind and the otherwise handicapped. Finally, there are innumerable special psychological problems growing out of the daily life of the individual which have sig nificance for his success, and warrant systematic investigation, such as the psychology of suggestion, of morale, of automobile and aeroplane accidents, and the psychological effects of drugs and stimulants. The characteristics of the major divisions will be indicated.

Educational Psychology.

The field of education represents the first practical activity in which psychology was systematically applied. So numerous and important have these applications become that "the act of teaching is now generally recognized to be based primarily upon the science of psychology." It forced attention upon the individual as the unit for instruction, and impelled educators to adapt their methods of teaching to suit him. Furthermore, it brought about the analysis of such school subjects as arithmetic into a large number of simple processes and opera tions, each of which must be cared for in the programme of instruction.

Along with this recognition of the individual, there goes the need for facilitating his progress and for measuring the rate of his progress. The facts of learning especially are constantly being canvassed for means of improving the conditions for learning, and elaborate test instruments are being devised for the measurement of pupils' achievement. Such facts as distribution of learning time, amount to be learned at a given time, the use of recitations, and other aids to learning are known to every teacher. Almost as widespread is the use of the various hand writing, composition, drawing and other scales for measuring accomplishment of school children. (See EDUCATIONAL PSY