430 Mental Factors in Evolution 



of its functioning may at least be provisionally conjectured in the 

 present state of physiological knowledge. Similarly in the case of 

 the pecking of newly-hatched chicks ; there is a visual presentation, 

 there is probably a cooperating group of stimuli from the alimentary 

 tract in need of food, there is an adaptive application of the activities 

 in a definite mode of behaviour. Like data are afforded in a great 

 number of cases of instinctive procedure, sometimes occurring very 

 early in life, not infrequently deferred until the organism is more 

 fully developed, but all of them dependent upon racial preparation. 

 No doubt there is some range of variation in the behaviour, just such 

 variation as the theory of natural selection demands. But there can 

 be no question that the higher animals inherit a bodily organisation 

 and a nervous system, the functional working of which gives rise to 

 those inherited modes of behaviour which are termed instinctive. 



It is to be noted that the term " instinctive " is here employed in 

 the adjectival form as a descriptive heading under which may be 

 grouped many and various modes of behaviour due to racial prepara- 

 tion. We speak of these as inherited; but in strictness what is 

 transmitted through heredity is the complex of anatomical and 

 physiological conditions under which, in appropriate circumstances, 

 the organism so behaves. So far the term " instinctive " has a 

 restricted biological connotation in terms of behaviour. But the 

 connecting link between biological evolution and psychological evolu- 

 tion is to be sought, as Darwin fully realised, in the phenomena 

 of instinct, broadly considered. The term "instinctive" has also 

 a psychological connotation. What is that connotation? 



Let us take the case of the swimming duckling or the pecking 

 chick, and fix our attention on the first instinctive performance. 

 Grant that just as there is, strictly speaking, no inherited behaviour, 

 but only the conditions which render such behaviour under appro- 

 priate circumstances possible ; so too there is no inherited experience, 

 but only the conditions which render such experience possible ; then 

 the cerebral conditions in both cases are the same. The biological 

 behaviour-complex, including the total stimulation and the total 

 response with the intervening or resultant processes in the sensorium, 

 is accompanied by an experience-complex including the initial 

 stimulation-consciousness and resulting response-consciousness. In 

 the experience-complex are comprised data which in psychological 

 analysis are grouped under the headings of cognition, affective tone 

 and conation. But the complex is probably experienced as an 

 unanalysed whole. If then we use the term ''instinctive" so as to 

 comprise all congenital modes of behaviour which contribute to 

 experience, we are in a position to grasp the view that the net result 

 in consciousness constitutes what we may term the primary tissue of 



