The Binet method of measuring intelligence and the hosts of practical psychological tests and special scales for mental measurement which have followed upon it are to-day re sponsible for renewed interest in the problems of ontogenetic psychology. It is even probable that these crude methods of mental measure ment . will eventually be so perfected as to further the solution of many genetic problems.
Animal psychology, other than human, has followed in the path blazed by Darwin and Preyer. First to appear were diary records of the development of young animals. Such are the psychological contributions of Wesley Mills, through his observations of dogs, cats and doves. Similar and more detailed ontogenetic studies have been made with mice, rats and the domestic fowl. Consult the works of Whit man, Craig; Breed, Pearl, Small, Watson, Allen and Yerkes.
Mental Even in the infancy of genetic psychology attempts were made to outline the process of mental evolution. Romans early presented a general scheme of development, and since his time various other speculative accounts of the course of mental evolution have been published. Such discus sions, although obviously demanding facts, have served the excellent purpose of stimulating re search. Conspicuously important stages in mental evolution are to-day being studied; but the animal series is a long one, and phyloge netic description is meagre, despite the rapid de velopment of animal psychology. Naturally enough, the line of evolution of the human mind has commanded attention, and in the at tempts which have been made to trace our ancestry, many vertebrate types have been studied more or less carefully. But despite their closeness of relationship to us, the other primates have been neglected, chiefly because of their costliness and the difficulties in keep ing and studying them. Neither the monkeys
nor the anthropoid apes, still less the lower types of primate, have been systematically studied, from the psychological point of view.
For a long time to come, phylogenetic psy chology must remain fragmentary and at loose ends. Facts will more and more abound, efforts to correlate them will become more numerous, and more fruitful, but the is long and it will require persistent and intensive effort to discover it. Yet, logically as well as psychologically, genetic description should be the primary aim of the student of psychology. It should be the material about which special modes of description should centre. Studies of particular groups of facts, as in plant psy chology, animal psychology, child psychology, the psychology of sex, of social relations, of ethnic groups; studies by special and peculiar methods, as for example the introspective, comparative, physiological; and studies for particular ends, like the educational, vocational, medical, theoretical, should all exist and thrive, for many and varied reasons. But each should have as its centre of reference genetic psy chology.
Baldwin, J. M., 'Mental Development in the Child and the Race' (New York 1906) ; Hall, G. Stanley, 'Adolescence' (2 vols., ib. 1905) ; Judd, C. H„ 'Genetic Psy chology for Teachers) (1903); Mills, W., 'The Nature and Development of Animal ; Moore, K. C., The Mental Develop melt of a Child,' No. 3 (1896) ; •Preyer, W., The Mind of the Child' (New York 18E8-89); Romanes, G. J., 'Mental Evolution in Animals' (London 1885); Spencer, H., • (New York 1890) ; Shinn, M. E., The Biography of a Baby' (1893) • Tracy and Stumpfl, 'The Psychology of Childhood ) (Boston 1910).