ORIGIN AND DEVELOPMENT OF INSTINCTS. 181 



which it states is a matter of daily observation. " Tricks of 

 manner," indeed, are of such frequent occurrence in the 

 nursery and schooboom, that it usually entails no small 

 labour on the part of elders to eradicate them, and when not 

 eradicated in childhood they are apt to continue through 

 life, unless afterwards conquered by the efforts of the indi- 

 vidual himself. But in cases where the trick of manner is 

 not obnoxious, or sufficiently unusual to call for checking, it 

 is allowed to persist, and thus it is that almost every one 

 presents certain slight peculiarities of movement which we 

 recognize as characteristic* 



Such peculiarities of movement as we meet with them in 

 ordinary life are slightly marked ; but their significance in 

 relation to instinct has been obtruded on my notice by 

 observing them in the much more striking form in which 

 they are presented by idiots. This is a class of persons 

 which, as we shall find in my next work, is of peculiar 

 interest in relation to mental evolution, because in them we 

 have a human mind arrested in its development as weU as 

 deflected in its growth — therefore in many cases supplying to 

 the comparative psychologist very suggestive material for 

 study. Now one of the things which must most strike any 

 one on first visiting an idiot asylum, is the extraordinary 

 character and variety of the meaningless tricks of manner 

 which are everywhere being displayed around him. These 

 tricks, often ludicrous, sometimes painful, but usually 

 meaningless, are always individual and wonderfully per- 

 sistent. Generally speaking, the lower the idiot in the scale 

 of idiotcy, the more pronounced is this peculiarity ; so that if 

 one sees a patient moving to and fro continually, or otherwise 

 exhibiting " rhythmical movements," one may be pretty sure 

 that the case is a bad one. But even among the higher idiots 

 and " feeble-minded," strange and habitual movements of the 

 hands, limbs, or features are exceedingly common. 



Among animals similar facts are to be noticed. Scarcely 

 any two sporting dogs " point " in exactly the same manner, 



* Dr. Carpenter says {Mental Physiology, p. 373), "What particular 

 ' trick ' each individual may learn, depends very much upon accident. Thus, 

 in the old times of dependent watch-chains and massive bunches of seals, 

 these were the readiest playthings," &c. In view of the relation which such 

 '"tricks" bear to the formation of primary instincts, this remark has some 

 importance ; it shows that even aimless movements may be determined and 

 rendered habitual by the conditions of the environment. 



