November i8, 189 ■.] 



SCIENCE. 



287 



the " motor square " diagram given below (Fig. 1). This is also 

 true when (3) sensations of the "remote" kinsesthetic order (the 

 sight or hearing of movements made) are added to the muscular 

 sensations. They may all coalesce to produce again a repetition 

 of the original reaction. The "remote" and "immediate" 

 sources of motor stimulation reinforce each other. This Is seen 

 in a child's satisfied repetition of its own mistakes in speaking 

 and drawing, where it hears and sees its own performances. Con- 



10. I. — Simple Imitation. v,v' = visual 8eat ; mp = motor seat ;mt = mus- 

 cle moved ; mc = muscle-eense seat ; A = " copy " imitated ; B = Imi- 

 tation made. The two processes v and v' coalesce and the reaction 

 is repeated without change or eSort. 



sequently (3) there is muscular effort only when the "copy" per- 

 sists and is compared with the result of the first reaction; that is. 

 on the physical side, when the two processes started by the " copy " 

 and the reactive result reach the higher co-ordinating centre 

 together. The stimulus to repeated efifort arises from the lack of 

 co-ordination or identity in the different stimulations which reach 

 the centre of co-ordination simultaneously. The mental outcome, 

 effort, accompanies the motor outburst of these combined in- 



FlQ. u.— Persistent Imitation with Effort. C=8ucc69sful imitation; cc— co-ordi- 

 nating center. (Other letters same as in Fig. I.) The processes at v 

 and v' do not coalesce but are co-ordinated at cc In a new reaction 

 mp', mt\ which Includes all the elements of the '*copy '' (A) and 

 more. The useless elements then fall away because they are useless 

 and the successful effort is established. 



fluences, and, as soon as this outbui'st reproduces the "copy," 

 the effort is said to •• succeed,' the subject is satisfied, "will-stim- 

 ulus " disappears, and the reaction tends to become simple as 

 habit. 



Physiologically the point which distinguishes persistent imita- 

 tion with effort from simple imitation with repetition is this con- 

 flict of processes in the centre. In simple imitation the excite- 

 ment aroused by the reaction, as its result is reported inwards by 



the eye or ear, finds no outlet except that already utilized in the 

 first discharge; hence it passes off in the way of a repetition of 

 this discharge. See Fig. I. 



In persistent imitation the first reaction is not repeated. Hence 

 we must suppose the development, in a new centre, of a function 

 of co-ordination by which the two regions excited respectively by 

 the original suggestion and the reported reaction coalesce in a 

 common more voluminous and intense stimulation of the motor 

 centre. A movement is thus produced which, by reason of its 

 greater mass and diffusion, includes more of the elements of the 

 " copy." This is again reported by eye or ear, giving a " remote" 

 excitement, which is again co-ordinated with the original stimu- 

 lation and with the after effects of the earlier imitations. The 

 result is yet another motor stimulation, or effort, of still greater 

 mass and diffusion, which includes yet more elements of the 

 "copy." And so on, until simply by its increased mass — by the 

 gi'eater range and variety of the motor elements enervated — 

 the "copy'' is completely reproduced. The effort thus succeeds. 

 See Fig. 3. 



When muscular effort thus succeeds by the simple fact of in- 

 creased mass and diffusion of reaction, the useless elements faH 

 away because they have no emphasis. The desired motor ele- 

 ments are reinforced by their agreement n ilh the " copy," by the 

 dwelling of attention upon them, by the pleasure which accom- 

 panies success. In short, the law of survival of the fittest by 

 natural, or, in this case, physiological, selection assures the per- 

 sistence of the reaction thus gained by effort. 



This theory of the physical process underlying volition is not 

 open to the objections commonly urged against earlier views- 

 How can we conceive the relation of mind and body? The 

 alternatives heretofore current are three : either the mind interferes 

 with brain processes, or it directs brain processes, or it does noth- 

 ing — these are the three. Now, on the view here presented, none 

 of these is true. The function of the mind is simply to have a 

 persistent presentation — a suggestion, a "copy." The law of 

 sensori-motor reaction does the rest. The muscles reflect the in- 

 fluence of the central excitement; this creates more excitement, 

 which the muscles again reflect ; and so on until, by the law of 

 lavish outlay, which nature so often employs, the requisite muscu- 

 lar combination is secured' and persists. 



Further, a direct examination of the infant's earliest voluntary 

 movements shows the growth in mass, diffusion, and lack of pre- 

 cision which this theory requires. In writing, the young child 

 uses hand, then hand and arm, then hand, arm, tongue, face, 

 and finally his whole body. In speaking, also, he "mouths" his 

 sounds, screws his tongue and hands, etc. And he only gets 

 his movements reduced to order after they have become by effort 

 massive and diffuse. I find no support whatever, in the children 

 themselves, for the current view of psychologists, i.e., that voluntary 

 combinations are gradually built up by adding muscle to muscle 

 and group to group. This is true only after each of these elements 

 has itself become voluntary. Such a view implies that the infant 

 at this stage knows that he uses his muscles, which is false; knows 

 which muscles he has learned to use, which is also false; and is 

 able to avail himself of muscles which he has not learned to use, 

 which is equally false — not to allude to the fact that it leaves 

 suspended in mid-air the problem as to bow the new combination 

 intended gets itself realized in the muscles. 



It is evident, also, that in accounting for the earliest voluntary 

 movements as cases of persistent imitative suggestion, we are 

 making the presentation which constitutes the "copy" a thing 

 imported into consciousness, a " suggested " thing which is im- 

 posed upon the infant by the necessities of its receptive nature. 

 And so it is. Whether and how the mind ever gets away from this 

 chain of suggestions or "copies," selects its own "copy" or end, 

 and secures by its own choice the persistence of it — this is the 

 question of voluntary attention. Its consideration would lead ub 

 too far afield from our present topic, the babies. 



' This application of the principle of " natural selection " to muscular 

 movement is so simple a solution of this crucial problem that I fear I must 

 have overlooked some suggestion of It in the literature of the subject. M 

 any rate, the tracing of it in the phenomena of imitative suggestion has not 

 occurred elsewhere. As a generwl h^p -taesis. hi wever, It is independent of 

 the question as to whether muscular effort is first found in imitation. 



