Permanence of Associations
Once formed, the connections by which, when an animal feels a certain sense-impression, he does a certain thing, persist over considerable intervals of time. With the curves on [pages 39 to 58] and [60 to 65] are given in many instances[17] additional curves showing the animal’s proficiency after an interval without experience. To these data may be added the following:—
The three chicks that had learned to escape through the long labyrinth (involving twenty-three associations) succeeded in repeating the performance after ten days’ interval. Similarly the chicks used as imitators in V, W, X and Y did not fail to perform the proper act after an interval of twenty days. Cat 6, who had had about a hundred experiences in C (button), had the association as perfect after twenty days as when it left off. Cat 2, who had had 36 experiences with C and had attained a constant time of 8 seconds, escaped fourteen days later in 3, 9 and 8 seconds, respectively, in three trials. Cat 1, after an interval of twenty days, failed in 10 minutes to escape from C. The signal for climbing up the front of the cage was reacted to by No. 3 after an interval of twenty-four days. No. 10, who had learned to discriminate between ‘I must feed those cats’ and ‘I will not feed them,’ was tried after eighty days. It was given 50 trials with the second signal mingled indiscriminately with 25 trials with the first. I give the full record of these, ‘yes’ equalling a trial in which she ‘forgot’ and climbed up, ‘no’ equalling a trial in which she wisely stayed down. Dashes represent intervening trials with the first signal, to which she always reacted. It will be observed that 50 trials put the cat in the same position that 350 had done in her first experience, although in that first experience she had had only about a hundred trials after the association had been perfected. The association between the first signal and climbing up was perfect after the eighty days.
Table 8
| Trials 1-7 | Trials 8-17 | Trials 18-27 | Trials 28-35 | Trials 36-42 | Trials 43-50 |
|---|---|---|---|---|---|
| — | yes | no | — | — | — |
| — | yes | yes | — | no | — |
| yes | yes | no | — | no | — |
| yes | — | no | no | — | — |
| no | yes | — | no | no | — |
| — | yes | — | yes | no | no |
| yes | no | yes | no | no | no |
| yes | yes | yes | — | — | yes |
| no | no | yes | no | — | no |
| no | — | yes | yes | no | no |
| — | — | no | no | no | no |
| — | yes | no | no | no | |
| — | yes | no | |||
| — |
All these data show that traces of the connections once formed are very slow in being lost. If we allow that part of the time in the first trial in all these cases is due to the time taken to realize the situation (time not needed in the trials when the association is forming and the animal is constantly being dropped into boxes), we may say that the association is as firm as ever for a considerable time after practice at it is stopped. How long a time would be required to annul the influence of any given quantity of experience, say of an association which had been gone through with ten times, I cannot say. It could, if profitable, easily be determined in any case. The only case of total loss of the association (No. 1 in C) is so exceptional that I fancy something other than lapse of time was its cause. The main interest of these data, considered as quantitative estimates, is not psychological, but biological. They show what a tremendous advantage the well-developed association-process is to an animal. The ways to different feeding grounds, the actions of enemies, the appearance of noxious foods, are all connected permanently with the proper reaction by a few experiences which need be reënforced only very rarely. Of course, associations without any permanence would be useless, but the usefulness increases immensely with such a degree of permanence as these results witness. An interesting experiment from the biological point of view would be to see how infrequently an experience could occur and yet lead eventually to a perfect association. An experiment approximating this is recorded in the time-curves for Box H in [Figure 7, on page 47]. Three trials at a time were given, the trials being two or three days apart. As may be seen from the curves, the association was readily formed.
The chief psychological interest of these data is that they show that permanence of associations is not memory. The fact that a cat, when after an interval she is put into box G, proceeds to immediately press the thumb piece and push the door, does not at all mean that the cat feels the box to be the same from which she weeks ago freed herself by pushing down that thumb piece, or thinks about ever having felt or done anything in that box. She does not refer the present situation to a situation of the past and realize that it is the same, but simply feels on being confronted with that situation the same impulse which she felt before. She does the thing now for just the same reason that she did it before, namely, because pleasure has connected that act above all others with that sense-impression, so that it is the one she feels like doing. Her condition is that of the swimmer who starts his summer season after a winter’s deprivation. When he jumps off the pier and hits the water, he swims, not because he remembers that this is the way he dealt with water last summer and so applies his remembrance to present use, but just because experience has taught him to feel like swimming when he hits the water. All talk about recognition and memory in animals, if it asserts the presence of anything more than this, is a gross mistake. For real memory is an absolute thing, including everything but forgetfulness. If the cat had real memory, it would, when after an interval dropped into a box, remember that from this box it escaped by doing this or that and consequently, either immediately or after a time of recollection, go do it, or else it would not remember and would fail utterly to do it. On the contrary, we have all grades of partial ‘forgetfulness,’ just like the grades of swimming one might find if he dropped a dozen college professors into the mill ponds of their boyhood, just like the grades of forgetfulness of the associations once acquired on the ball field which are manifested when on the Fourth of July the ‘solid men’ of a town get out to amuse their fellow citizens. The animal makes attacks on a spot around the vital one, or claws at the thing—but not so precisely as before, or goes at it a while and then resorts to instinctive methods of getting out. Its actions are exactly what would be expected of an animal in whom the sense-impression aroused the impulse imperfectly, or weakly, or intermittently, but are not at all like the actions of one who felt, “I used to get out of this box by pulling that loop down.” In fact, the record of No. 10 given on [page 139] seems to be final on this point. If at any time in the course of the 50 trials it had remembered that ‘I will not feed them’ meant ‘no fish,’ it would thenceforth have failed to react. It would have stopped short in the ‘yes’ reactions, instead of gradually decreasing their percentage. ‘Memory’ in animals, if one still chooses to use the word, is permanence of associations, not the presence of an idea of an experience attributed to the past.
To this proposition two corollaries may be added. First, these phenomena of incomplete forgetfulness extend the evidence that animals do not have a stock of independent ideas, the return of which, plus past associates, equals memory. Second, there is, properly speaking, no continuity in their mental streams. The present thought does not clutch the past to its bosom or hold the future in its womb. The animal’s self is not a being ‘looking before and after,’ but a direct practical association of feelings and impulses. So far as experiences come continuously, they may be said to form a continuous mental life, but there is no continuity imposed from within. The feelings of its own body are always present, and impressions from outside may come as they come to us. When the habit of attending to the elements of its associations and raising them up into the life of free ideas is acquired, these permanent bodily associations may become the basis of a feeling of self-hood and the trains of ideas may be felt as a continuous life.
Inhibition of Instincts by Habit
One very important result of association remains to be considered, its inhibition of instincts and previous associations. An animal who has become habituated to getting out of a box by pulling a loop and opening the door will do so even though the hole in the top of the box be uncovered, whereas, if, in early trials, you had left any such hole, he would have taken the instinctive way and crawled through it. Instances of this sort of thing are well-nigh ubiquitous. It is a tremendous factor in animal life, and the strongest instincts may thus be annulled. The phenomenon has been already recognized in the literature of the subject, a convenient account being found in James’ ‘Psychology,’ Vol. II, pages 394-397. In addition to such accounts, one may note that the influence of association is exerted in two ways. The instinct may wane by not being used, because the animal forms the habit of meeting the situation in a different way, or it may be actually inhibited. An instance of the former sort is found in the history of a cat which learns to pull a loop and so escape from a box whose top is covered by a board nailed over it. If, after enough trials, you remove a piece of the board covering the box, the cat, when put in, will still pull the loop instead of crawling out through the opening thus made. But, at any time, if she happens to notice the hole, she may make use of it. An instance of the second sort is that of a chick which has been put on a box with a wire screen at its edge, preventing her from jumping directly down, as she would instinctively do, and forcing her to jump to another box on one side of it and thence down. In the experiments which I made, the chick was prevented by a second screen from jumping directly from the second box also. That is, if in the accompanying figure, A is a box 34 inches high, B a box 25 inches high, C a box 16 inches high, and D the pen with the food and other chicks, the subject had to go A-B-C-D. The chick tried at first to get through the screen, pecked at it and ran up and down along it, looking at the chicks below and seeking for a hole to get through. Finally it jumped to B and, after a similar process, to C. After enough trials it forms the habit and when put on A goes immediately to B, then to C and down. Now if, after 75 or 80 trials, you take away the screens, giving the chick a free chance to go to D from either A or B, and then put it on A, the following phenomenon appears. The chick goes up to the edge, looks over, walks up and down it for a while, still looking down at the chicks below, and then goes and jumps to B as habit has taught it to do. The same actions take place on B. No matter how clearly the chick sees the chance to jump to D, it does not do so. The impulse has been truly inhibited. It is not the mere habit of going the other way, but the impossibility of going that way. In one case I observed a chick in whom the instinct was all but, yet not quite, inhibited. When tried without the screen, it went up to the edge to look over nine times, and at last, after seven minutes, did jump straight down.