Instinctive Behaviour 431 



experience. To the deyelopment of this experience each instinctive 

 act contributes. The nature and manner of organisation of this 

 primary tissue of experience are dependent on inherited biological 

 aptitudes ; but they are from the outset onwards subject to secondary 

 development dependent on acquired aptitudes. Biological values are 

 supplemented by psychological values in terms of satisfaction or the 

 reverse. 



In our study of instinct we have to select some particular phase 

 of animal behaviour and isolate it so far as is possible from the life 

 of which it is a part. But the animal is a going concern, restlessly 

 active in many ways. Many instinctive performances, as Darwin 

 pointed out^, are serial in their nature. But the whole of active life 

 is a serial and coordinated business. The particular instinctive 

 performance is only an episode in a life-history, and every mode of 

 behaviour is more or less closely correlated with other modes. This 

 coordination of behaviour is accompanied by a correlation of the 

 modes of primary experience. We may classify the instinctive modes 

 of behaviour and their accompanying modes of instinctive experience 

 under as many heads as may be convenient for our purposes of inter- 

 pretation, and label them instincts of self-preservation, of pugnacity, 

 of acquisition, the reproductive instincts, the parental instincts, and 

 so forth. An instinct, in this sense of the term (for example the 

 parental instinct), may be described as a specialised part of the 

 primary tissue of experience differentiated in relation to some definite 

 biological end. Under such an instinct will fall a large number of 

 particular and often well-defined modes of behaviour, each with its 

 own peculiar mode of experience. 



It is no doubt exceedingly difficult as a matter of observation and 

 of inference securely based thereon to distinguish what is primary 

 from what is in part due to secondary acquisition — a fact which 

 Darwin fully appreciated. Animals are educable in different degrees; 

 but where they are educable tliey begin to profit by experience from 

 the first. Only, therefore, on the occasion of the first instinctive act 

 of a given type can the experience gained be regarded as ivholly 

 primary ; all subsequent performance is liable to be in some degree, 

 sometimes more, sometimes less, modified by the acquired disposition 

 Avhich the initial behaviour engenders. But the early stages of 

 acquisition are always along the lines predetermined by instinctive 

 differentiation. It is the task of comparative psychology to distin- 

 guish the primary tissue of experience from its secondary and 

 acquired modifications. We cannot follow up the matter in further 

 detail. It must here suffice to suggest that this concei)tion of instinct 

 as a primary form of experience lends itself better to natural history 



1 Origin of Species (Gth edit.), p. 206. 



