Mat 1, 1914] 



SCIENCE 



627 



the general subject of man's behavior, are 

 indicative rather of the realization of the 

 need of knowledge than of the existence of 

 such knowledge. Without exception, such 

 general discussions as the writer is familiar 

 with display our ignorance of the facts of 

 behavior and of the principles underlying 

 them and serve rather as arguments in 

 favor of the systematic study of this grovip 

 of phenomena than as satisfactory treatises. 



The behaviorist, whether he be physiolo- 

 gist or psychologist at heart, seeks, first of 

 all, accurate knowledge of the facts of be- 

 havior. His task it is to analyze behavior- 

 complexes, to discover their conditions or 

 causes, to formulate the laws of their ap- 

 pearance, and to point the way to their 

 control. It matters not to him whether 

 his subject happens to be a horse, an ape, or 

 a man. He adapts his methods of investi- 

 gation to the problem and the subject in 

 hand and proceeds to gather data. It is 

 characteristic of the recent experimental 

 work in behavior that reactions to simple 

 or complex situations should be broken up 

 into smaller and smaller part processes, and 

 the characteristics of these processes as well 

 as their relations, studied minutely, per- 

 sistently, accurately. 



Our time-honored classification of activ- 

 ities as reflex, instinctive, impulsive, habit- 

 ual, voluntary, is no longer in favor. In- 

 deed, the speculative discussion of the char- 

 acteristics of dii?erent types of activity and 

 attempts to formulate definitions which 

 shall render these types mutually exclusive 

 have to-day given place to systematic search- 

 ing for the characteristics or attributes of 

 acts and groups of acts, and for genetic 

 descriptions thereof. Only recently, it 

 must be confessed, have we fully realized 

 that an instinctive act is something to be 

 observed and reobserved under varied and 

 rigidly controlled conditions; something to 

 be studied in its origin and development; 



something to be created, if possible, by the 

 control of conditions of organic behavior, 

 rather than something merely to be talked 

 about or defined in abstract terms. The 

 older literature of instinct is vague, gen- 

 eral, speculative. The newer is definite, 

 concrete, observational. And what is true 

 of our studies of instinct is true, likewise, 

 of our studies of the various senses and of 

 habits. 



It is rather late in this discussion to 

 define behavior, yet an attempt to do so 

 may serve to correct certain misimpressions 

 which seem not uncommon. The term, as 

 used by the scientist to-day, is inclusive 

 not merely of those gross and obvious activ- 

 ities exhibited by man in common with the 

 other animals, but of hidden organic proc- 

 esses. The behaviorist is interested quite 

 as much in reflexes, which might ordinarily 

 be relegated to physiology, as in habitual, 

 or instinctive, or voluntary acts. But he is 

 interested, also, as much in the complex 

 forms of behavior, known as conduct, as in 

 the simpler expressions of human intelli- 

 gence. Indeed, even the most complex 

 moral and religious forms of activity are 

 regarded by him as material for scientific 

 study. 



A strictly scientific study of the varieties 

 of human behavior demands, first, the for- 

 mulation of problems, for advance comes 

 slowly and uncertainly unless the investi- 

 gator can definitely formulate his task. It 

 demands, further, thorough knowledge of 

 the methods of physiology, of psychology, 

 of physics, and of chemistry, and ingenuity 

 on the part of the experimenter in adapting 

 these methods to his immediate needs. 

 Finally, it demands familiarity with the 

 facts of behavior in other organisms, in 

 order that the comparative method may be 

 made to lend abundant aid. 



Noteworthy changes have occurred in the 

 study of behavior during the past twenty 



