April 29, 1922] 



NA TURE 



551 



Memory. 



Memory is the power to learn, to grow mentally in 

 response to functional activity, to profit from experi- 

 ence, and so to become intelligent. It has its counter- 

 part in the power to develop physically in response to 

 use. Its evolution occurred especially among the 

 higher animals, and was accompanied by a general 

 retrogression of instinct. Nevertheless, at least four 

 new instincts were evolved, each of which incites to 

 learning, and without which little or no intelligence 

 could develop, no matter how great the capacity to 

 learn. 



(i) The parental instinct incites to the protection 

 and training of offspring. It wanes when offspring 

 are fit to fend for themselves. 



(2) The instinct of sport impels the individual to 

 develop both body and mind in exactly the right 

 directions. Thus the kid climbs and butts, and the 

 kitten stalks and pounces. This instinct wanes as 

 the individual reaches maturity and ability to battle 

 for existence. It lingers longest in human beings 

 who remain capable of some mental development even 

 to old age. But the character of human sport 

 gradually changes from those contests of strength and 

 endurance which developed the boy to those which 

 merely maintain physical development, or else are 

 pure contests of skill and wit. Thus the mature man 

 ceases to wrestle, and amuses himself instead with 

 golf, bowls, cards, and the like. 



(3) The instinct of imitation incites the individual 

 to learn (from the examples furnished by his com- 

 panions) how to act and what to think. It often 

 works in combination with play (for much play is 

 mimicry), and wanes in the individual even more 

 swiftly and in a greater degree than the latter. While 

 it persists in strength the individual is termed 

 " plastic." It is best developed in man, who learns 

 through imitation not only such habitual actions as 

 ■valking and speaking a language, but also the habits 



f thought, the general outlooks on life, the ambitions, 

 .ud the emotional convictions as to what is true and 

 light that distinguish the community (or section of 

 it) in which he is reared, savage or civilised. Christian 

 or Mohammedan, Catholic or Protestant, lowly or 

 exalted, and so on. In this way he fits himself for 

 life in that particular environment. Thus, mainly, is 

 fashioned what is termed his " character," his general 

 mental disposition. As the twig is bent, so the tree 

 grows. Hence the importance of good homes, com- 

 panions, and schools. As this instinct wanes the 

 character sets. The same kind of things are no longer 

 learned, at any rate to the same extent and with equal 

 facility. Compare language as learned by a child 

 and by an adult. It follows that the traits created 

 by imitation tend to be very stable, for they are not 

 afterwards displaced by others of the same kind. 

 The boy becomes the father of the man. 



(4) The instinct of curiosity impels the individual 

 to seek for, and learn from, evidence. Unlike imita- 

 tion, it persists with relatively little diminution even 

 to old age. To it (and to labour) the individual owes 

 the main part of his mental development after child- 

 hood, his intelligence, his reason. It creates, not 

 sentimental, but intellectual convictions. Since it 

 persists during life, the ideas acquired through it tend 

 to be unstable — apt to be displaced by others which 

 seem founded on superior evidence. 



(5) Apart from instinct, man, especially civilised 

 man, has invented labour, to which he is impelled 

 by the intelligence created through his memory, and 

 from which he learns to become yet more intelligent, 

 efficient, and laborious. Thus, as indicated by Prof. 

 Goodrich, in the mental, as in the physical, world 



NO. 2739, VOL. 109] 



each stage of development furnishes the basis for the 

 next until full development is achieved. Labour 

 commonly lacks the pleasure and interest which 

 accompany the instinctive activities. Thus, while 

 men never delegate the latter {e.g. eating, sporting, 

 and love-making) to others, they often delegate the 

 labours to which they are prompted by intelligence. 

 Like play and imitation, but unlike curiosity, labour 

 tends to create habitual " physical " dexterities — 

 which are really mental, for the (subconscious) mind 

 co-ordinates the muscles. On the other hand, the 

 intellectual traits created by labour resemble those 

 created by curiosity. 



We are concerned especially with the products of 

 imitation and curiosity. All the rest of the " make- 

 up " of man's mind is relatively simple and obvious. 

 His instincts, few in number and definite in character, 

 are identical in kind for all men. At most this man 

 or this race may have this instinct or that (e.g. the 

 sexual or parental) more or less developed than this 

 or that other. Again, all men except idiots are 

 eminently educable. They differ in capacities for 

 learning, but yet more in the way in which the 

 capacity is used. Apart from play and labour, the 

 results of which are glaringly obvious, men learn 

 only through imitation and curiosity ; and accord- 

 ingly as they acquire more through the one than 

 through the other, their characters are shaped and 

 the fates of nations decided. Here must the parent 

 ^nd the pedagogue learn or be impotent. Here must 

 the man of science labour, or charlatans and fanatics 

 will for ever dominate the body politic. 



The mental traits created by imitation and 

 curiosity differ sharply. Not only are convictions 

 derived from example very stable, but they are tinged 

 with emotion, and even passion. The reverse is the 

 case with those derived from evidence. Compare 

 moral and religious convictions, which belong to the 

 former category, with business and scientific beliefs, 

 which belong to the latter. A reUgious and ethical 

 system may conflict daily with common sense (i.e. 

 evidence), and yet persist for a hundred generations. 

 But the knowledge and ideas acquired through 

 curiosity change in every man with every year. When 

 men believed on grounds of faith {i.e. through imita- 

 tion) that the w^orld was flat they burned dissentients ; 

 to-day, when they believe on grounds of fact {i.e. on 

 grounds of evidence) that it is round, they are con- 

 temptuously indifferent. Every missionary knows the 

 ease with which the children of non-Christians may be 

 trained to his beliefs and ideals, and the difl&culty 

 and danger of trying to convert adults. A child 

 who is taught that honesty is right will for ever hold 

 that opinion ; an adult taught that honesty is the 

 best policy may easily change. If there be such 

 things as absolute right and wrong, the human mind 

 is incapable of knowing them ; for the conscience, 

 chameleon-like, is a product of imitation. Thus at 

 different times and places everything, from pro- 

 miscuous sexual intercourse to rigid abstention from 

 all intercourse, has been held holy, or permissible, 

 or damnable, and conscience has pricked men corre- 

 spondingly. 



The traits created by imitativeness — habitual emo- 

 tions and ways of acting- — resemble closely the in- 

 stinctive emotions and actions. Thus men and horses 

 walk, men and ants are social, men and bees defend 

 their communities ; but while the men have learned, 

 the others have not. The love of a human mother 

 for her baby is instinctive, that for her mature 

 offspring is habitual ; yet the one passes insensibly 

 into the other. Did we not know that the children 

 of Mohammedans could be trained to other beliefs 

 and ideals we might think the fanaticism of the 

 adults instinctive. So closely do habitual actions and 



