182 SECTIONAL ADDRESSES. 



remarkable fact emerged that, at this stage, with exactly the same 

 stimulus, the eye-blink reflex may occur for a few times and then cease, 

 and then recur again : it may occur nearly every time in about a dozen 

 tests one day and in only one or two or even not at all on another day, 

 and so on with no apparent cause of variation. The common definition 

 of a reflex as the ' invariable response,' etc., is misleading : and the testing 

 two or three times of this reflex in a strange child at this age, quite 

 unreliable.* 



Further general daily observation and testing of this and other reflexes 

 in my children suggested most decidedly that reflexes are affected by the 

 general condition of the infant at the moment ; that a reflex may appear 

 for a time and then vanish (as the walking reflex at four weeks) ; and that 

 the dividing line between the so-called reflexes (at least the sensation- 

 reflexes) and instincts is hard to draw, not because all instincts are merely 

 reflexes (as ordinarily understood), but because what have been called 

 mere mechanical reflexes are more complex than supposed, less inevitable,' 

 more capable of improvement with practice, more the reaction of the 

 whole mechanism, and otherwise more similar to instincts. 



I have already contended that the occasional testing or study, at a 

 given age, of a group of children, needs to be checked by day-by-day 

 observations on the same child in the home environment. It is such study 

 which convinces me of the importance of the influence of general ' tone,' 

 condition or mood on performance. Dr. Gesell says that fatigue does not 

 affect the result of tests much, and that even illness does not ' completely 

 mask ' the stage of development. This, I think, is only true if we refer 

 to well-established reflexes or habits and responses ; it does not hold of 

 nascent functions that is functions during the period when they are just 

 beginning to appear. I have noted frequently that new appearances 

 may only take place, for the nascent period, under favourable circum- 

 stances. This applies to higher functions such as elementary thought 

 processes, the use of number, and so on, as well as to such phenomena as 

 imitation, laughter, and some reflexes ; but one only fully realises this 

 if one tests daily for some new function, somewhat earlier than it has ever 

 been found by others. 



Daily observations and a knowledge of the influence of varying 

 circumstances on the child are still more important when we study the 

 more complex problems of instincts. How far, for example, are fears 

 dependent on innate disposition, and how far on suggestion or experience ? 



There is little doubt that the divergence of reports as to whether there 

 are innate fears of animals, of furs, of the dark and so on, is due partly 

 to differences of conditions under which the observations are made. If 

 an infant in the mother's arms is less likely to show the eyeblink reflex 

 at the bang of a door than if it be alone in a cot, the full fear reaction is 

 still more likely to be affected by favourable or unfavourable conditions. 

 The principle of summation of stimuli holds in the sphere of instinctive 

 responses. In some experiments on the fear of animals intended to test 

 Watson's theory that such fears are ' all due to experience and association,' 



8 A detailed account of this experiment is given in my article Reflexes in Early 

 Childhood : Their Development, Variability, Evanescence, Inhibition and Eelation to 

 Instincts. Brit. Journ. of Medical Psych., vol. vii., 1927. 



