Fig. 28.
In discussing these facts we may first of all clear our way of one popular explanation, that this learning was due to ‘reasoning.’ If we use the word reasoning in its technical psychological meaning as the function of reaching conclusions by the perception of relations, comparison and inference, if we think of the mental content involved as feelings of relation, perceptions of similarity, general and abstract notions and judgments, we find no evidence of reasoning in the behavior of the monkeys toward the mechanisms used. And this fact nullifies the arguments for reasoning in their case as it did in the case of the dogs and cats. The argument that successful dealings with mechanical contrivances imply that the animals reasoned out the properties of the mechanisms, is destroyed when we find mere selection from their general instinctive activities sufficient to cause success with bars, hooks, loops, etc. There is also in the case of the monkeys, as in that of the other mammals, positive evidence of the absence of any general function of reasoning. We shall find that at least very many simple acts were not learned by the monkeys in spite of their having seen me perform them again and again; that the same holds true of many simple acts which they saw other monkeys do, or were put through by me. We shall find that after having abundant opportunity to realize that one signal meant food at the bottom of the cage and another none, a monkey would not act from the obvious inference and consistently stay up or go down as the case might be, but would make errors such as would be natural if he acted under the growing influence of an association between sense-impression and impulse or sense-impression and idea, but quite incomprehensible if he had compared the two signals and made a definite inference. We shall find that, after experience with several pairs of signals, the monkeys yet failed, when a new pair was used, to do the obvious thing to a rational mind; viz., to compare the two, think which meant food, and act on the knowledge directly.
Table 9
| No. 1. | No. 2. | No. 3. | |||||||
|---|---|---|---|---|---|---|---|---|---|
| Min. Sec. | Min. Sec. | Min. Sec. | |||||||
| Box TT (nail plug) | Oct. 19, 1900 | 0.40 | Oct. 21, 1900 | 14.10 | Oct. 21, 1900 | 36.00 | |||
| Box UU (old plug at side) | Oct. 19, 1900 | F 60.00 | |||||||
| Box VV (wire loop) | Oct. 20, 1900 | {F 10.00 | Oct. 24, 1900 | F 10.00 | Oct. 22, 1900 | {F 10.00 | |||
| {F 10.00 | Oct. 25, 1900 | F 10.00 | {F 10.00 | ||||||
| {F 10.00 | {F 10.00 | ||||||||
| Box WW (bar inside) | Oct. 20, 1900 | F 10.00 | Oct. 21, 1900 | 5.00 | after F 30.00 | Oct. 22, 1900 | {F 10.00 | ||
| Oct. 24, 1900 | {F 5.00 | ||||||||
| {F 10.00 | |||||||||
| {F 15.00 | |||||||||
| Box XX (bar outside) | Oct. 23, 1900 | im. | after [25] F 10.00 | Oct. 24, 1900 | 3.40 | Oct. 23, 1900 | .30 | ||
| Box YY (push bar) | Oct. 30, 1900 | 2.00[26] | |||||||
| Box Beta (single hook) | Oct. 30, 1900 | 9.00 | after F 10.00 and 10.00 | Oct. 24, 1900 | im. | ||||
| Box LL (triple; nail plug, hook and bar outside) | Nov. 4, 1900 | 16.00[27] | Oct. 3, 1900 | 2.00 | Nov. 3, 1900 | 1.45 | |||
| Box Alpha (catch at back) | Nov. 5, 1900 | .35 | Oct. 5, 1900 | 6.00 | Nov. 5, 1900 | ||||
| Box KK (triple; bolt, side-plug and knob) | Nov. 7, 1900 | F 10.00 F 10.00 | Oct. 7, 1900 | F 60.00 | Nov. 7, 1900 | F 10.00 | |||
| Box Theta (bolt at top) | Nov. 19, 1900 | F 10.00 | Jan. 8, 1901 | F 10.00 | |||||
| Box Eta (ring at back) | Dec. 17, 1900 | im. | Dec. 17, 1900 | 4.20 | |||||
| App. QQ (push chute) | Dec. 17, 1900 | F 60.00 | |||||||
| Box Gamma (wind) | Jan. 3, 1901 | .20 | Jan. 4, 1901 | F 10.00 | |||||
| F 10.00 | |||||||||
| Box Delta (push back) | Jan. 4, 1901 | F 5.00 F 5.00 | Jan. 4, 1901 | 2.10 | after[28] F 10.00 | ||||
| App. QQ (a) (bar chute) | Jan. 6, 1901 | 8.00 | Jan. 7, 1901 | F 10.00 | |||||
| Box Zeta (new side plug) | Jan. 7, 1901 | 1.10 | after F 5.00 | Jan. 8, 1901 | .50 | ||||
| App. QQ (b) (2½ revolution chute) | Jan. 9, 1901 | 3.00 | Jan. 8, 1901 | F 10.00 | |||||
| App. QQ (c) (nail-plug chute) | Jan. 11, 1901 | F 5.00 F 5.00 | Jan. 11, 1901 | F 5.00 F 5.00 | |||||
| Box Epsilon (push down) | Jan. 12, 1901 | F 5.00 F 10.00 | Jan. 12, 1901 | F 10.00 | |||||
| App. QQ (d) (ring chute) | Jan. 16, 1901 | F 5.00 F 5.00 | Jan. 16, 1901 | im. | |||||
| App. QQ (e) (hook chute) | Jan. 16, 1901 | F 5.00 | |||||||
| App. QQ (f) (string chute) | Jan. 17, 1901 | F 5.00 | |||||||
| App. QQ (ff) (string-wire chute) | Jan. 17, 1901 | .20 | Jan. 19, 1901 | F 5.00 F 5.00 | |||||
The methods one has to take to get them to do anything, their general conduct in becoming tame and in the experiments throughout, confirm these conclusions. The following particular phenomena are samples of the many which are inconsistent with the presence of reasoning as a general function. No. 1 had learned to open a door by pushing a bar around from a horizontal to a vertical position. The same box was then fitted with two bars. He turned the first bar round thirteen times before attempting to push the other bar around. In box LL all three monkeys would in the early trials do one or two of the acts over and over after they had once done them. No. 1, who had learned to pull a loop of wire off from a nail, failed thereafter to pull off a similar loop made of string. No. 1 and No. 3 had learned to poke their left hands through the cage for me to take and operate a chute with. It was extremely difficult to get either of them to put his right hand through or even to let me take it and pull it through.
A negative answer to the question “Do the monkeys reason?” thus seems inevitable, but I do not attach to the question an importance commensurate with the part it has played historically in animal psychology. For I think it can be shown, and I hope in a later monograph to show, that reasoning is probably but one secondary result of the general function of having free ideas in great numbers, one product of a type of brain which works in great detail, not in gross associations. The denial of reasoning need not mean, and does not to my mind, any denial of continuity between animal and human mentality or any denial that the monkeys are mentally nearer relatives to man than are the other mammals.
So much for supererogatory explanation. Let us now turn to a more definite and fruitful treatment of these records.
The difference between these records and those of the chicks, cats and dogs given on [pages 39-65] passim is undeniable. Whereas the latter were practically unanimous, save in the cases of the very easiest performances, in showing a process of gradual learning by a gradual elimination of unsuccessful movements, and a gradual reënforcement of the successful one, these are unanimous, save in the very hardest, in showing a process of sudden acquisition by a rapid, often apparently instantaneous, abandonment of the unsuccessful movements and a selection of the appropriate one which rivals in suddenness the selections made by human beings in similar performances. It is natural to infer that the monkeys who suddenly replace much general pulling and clawing by a single definite pull at a hook or bar have an idea of the hook or bar and of the movement they make. The rate of their progress is so different from that of the cats and dogs that we cannot help imagining as the cause of it a totally different mental function, namely, free ideas instead of vague sense-impressions and impulses. But our interpretation of these results should not be too hasty. We must first consider several other possible explanations of the rapidity of learning by the monkeys before jumping to the conclusion that the forces which bring about the sudden formation of associations in human beings are present.