Novembers, 1919] 



NATURE 



209 



French guidance of Ribot and Janet, who laid 

 the foundations of our modern conceptions of the 

 disorders of memory and personality, and of 

 Binet, who was among the first systematically to 

 study individual mental differences and to devise 

 tests of mental ability. 



In the United States, under the influence of 

 Stanley Hall and Titchener, and in Scandinavia, 

 the German tradition was at first faithfully up- 

 held. Most American, like most German, psycho- 

 logists had their earlier training in philosophy, 

 and the work published generally followed along 

 German lines, consisting often in "maiden" 

 papers written by candidates for the doctorate of 

 philosophy. In this country, especially through 

 the influence of Rivers, who went to Cambridge 

 in the early 'nineties at the invitation of Michael 

 Foster as lecturer in the physiology of the sense- 

 organs, experimental psychology has developed 

 on rather different lines. It has seldom received 

 more than lukewarm support from philosophy, 

 and it has been taken up by maturer workers, 

 fewer in number, who in several instances came 

 to it from physiology and medicine. Thus, Rivers 

 and MacDougall began their psychological work on 

 vision, and Myers on hearing, while later Spear- 

 man, who had graduated under Wundt, special- 

 ised in the correlation of mental abilities. In this 

 country scientific psychology has never suffered, 

 as in America, from the dangers of excessive 

 popularity. Here stress came to be laid on one or 

 other of the aspects of comparative psychology, 

 rather than on the pure experimental psychology of 

 the German laboratory. For it was quickly recog- 

 nised that the mental differences found under dif- 

 ferent experimental conditions in any given in- 

 dividual are generally less in degree and less in 

 significance than those observed under the same 

 conditions in different individuals. True, both in 

 England and in Germany there have been import- 

 ant investigations carried out upon the effects of 

 alcohol and other drugs on the mental processes 

 of a given individual. But even here, as also in 

 the striking researches of Ebbinghaus and G. E. 

 Miiller on memory, the special interest has been 

 found to lie in the study of the behaviour of dif- 

 ferent individuals. The Cambridge .Anthropo- 

 logical Expedition to the Torres Straits, under 

 the leadership of Haddon, which included in its 

 personnel three psychologists, and the later rapid 

 growth of the applied sciences of educational, 

 industrial, and medical psychology, have likewise 

 helped to stimulate the study of comparative 

 psychology in this country. 



But in Germany and in America there have 

 also been signs of a breaking away from the 

 initial, less fruitful (though fundamental) themes 

 of research. Stern's work on individual psycho- 

 logy, following the pioneer investigations of 

 Francis Galton in this country, and the work on 

 animal behaviour by Jennings, Thorndike, and 

 Yerkes in America, based on the foundations laid 

 here by Romanes and by Lloyd Morgan, are 

 examples in point. 



NO. 2610, VOL. 104] 



The insufficiency of the older introspective 

 psychology, whether studied in the laboratory or 

 outside it, has since been growing more and more 

 obvious. Watson and others have vainly sought 

 to establish a psychology expressed merely in 

 terms of behaviour, Loeb and Pawlow in terms 

 of purely mechanical or physiological processes. 

 Head and his collaborators have shown the impos- 

 sibility of analysing and tracing the evolution 

 of sensory and higher processes save by studying 

 the effects of lesions in the peripheral nerves and 

 the central nervous system. Freud and his fore- 

 most pupils and critics have indicated the enor- 

 mous importance of the study of the emotional, 

 instinctive, and sub-conscious processes which 

 are inaccessible to introspective examination. 

 Whether or not we accept Freud's views in their 

 entirety, his work has given an enormous impetus 

 to psychology by laying stress on the conflicts 

 arising from rival incompatible mental (especially 

 emotional) processes, and by indicating the dif- 

 ferent principles which Nature and the physician 

 may employ to combat such conflicts. The pub- 

 lished experiences of MacCurdy and others of the 

 American Army, and of Brown, Hart, 

 MacDougall, Myers, Pear, Rivers, Rows, and 

 other psychologists engaged in the treatment of 

 functional nervous and mental disorders in the 

 British Army during the recent war, have also 

 shown how much can be done by the early 

 application of appropriate psycho-therapeutic 

 methods to the cure of such disorders. 



The war has likewise emphasised, both in this 

 country and especially in America, the great value 

 of psychological tests in the selection of candi- 

 dates for the work to which they are best fitted. 

 The importance of psychological experiment is 

 now becoming recognised not only in regard to 

 vocational guidance, but also in regard to 

 industrial fatigue, the effects of different 

 lengths and distributions of periods of work and 

 rest, etc. 



There was a time now past when in the popular 

 view psychological research was supposed to be 

 limited to reaction time experiments, or was con- 

 fused with "psychical research " into spiritualistic 

 phenomena. It is true that the enormous amount 

 of labour spent in Germany on reaction time 

 experiments promises at length useful results in 

 the study of emotional complexes and of voca- 

 tional selection. And only by the narrow-minded 

 can psychical research be excluded from psycho- 

 logical science provided that it be conducted by 

 workers systematically trained in experimental 

 methods and freed from personal bias and preju- 

 dice. But the most promising future develop- 

 ments of psychology may be looked for along 

 quite other lines, which have been already briefly 

 indicated in the foregoing account of its present 

 position, more especially in the study of the 

 effects of nervous lesions and of mental and 

 nervous disorders, and in the examination 

 and recognition of individual mental differ- 

 ences. 



