468 E. L. THORNDIKE AND C. J. HERRICK 



logical endeavors by the acquisition of new points of view. 

 The study of familiar facts in a new setting is often all that 

 is necessary to point the way to entirely new methods of attack. 



A review of neurological literature, especially in the field of 

 comparative neurology, reveals a prodigious amount of research 

 from which surprisingly few generalizations can be deduced 

 which are of great interest to students of either animal behavior 

 or human psychology. This literature has its own problems, 

 in the solution of which it has not been wholly unsuccessful; 

 but these problems have always been sharply circumscribed by 

 the limitations of technique, not the least of which has been the 

 failure of investigators in this field to make a correlated study 

 of both the structure and the functions of their objects of re- 

 search. Doctor Watson's recommendation that extensive pro- 

 grams of research be carried out with the cooperation of behav- 

 iorists, experimental physiologists and neurologists is a sug- 

 gestion of constructive value. In short, while the technique of 

 each discipline needs improvement, the greatest need is for a 

 technique of cooperation. 



In the discussion of instinct, biologists, behaviorists and 

 psychologists all claim an interest. All behavior is complex, 

 and it has been common for each student of animal life to select 

 from this complex the particular factors which seemed best to 

 fit into his own philosophical preconceptions and to use these 

 factors only in formulating his conception of instinct. 



In contrasting instinct and habit (p. 185) Doctor Watson 

 clearly states the cardinal principle which alone can bring order 

 out of the chaotic and hazy notions which are current. This 

 principle is the sharp distinction between the innate and the 

 acquired factors in behavior. All agree that a reflex is the 

 function of an innate mechanism. Now when reflexes are 

 combined, as we always find them in behavior complexes, the 

 order and pattern of their combination may likewise be deter- 

 mined by the hereditary organization, or this pattern may be 

 acquired during the individual life of the animal. In the former 

 case we are .dealing with a pure instinct; in the latter case with 

 a pure habit. This is Watson's terminology. I would add, 

 that, in any concrete example of behavior in a higher animal, 

 both of these types are almost certain to be present, and so the 

 particular act cannot as a rule be classified off-hand as instinc- 



