THE EVOLUTION OF THE HUMAN INTELLECT[46]
To the intelligent man with an interest in human nature it must often
appear strange that so much of the energy of the scientific world has
been spent on the study of the body and so little on the study of the
mind. ‘The greatest thing in man is mind,’ he might say, ‘yet the least
studied.’ Especially remarkable seems the rarity of efforts to trace the
evolution of the human intellect from that of the lower animals. Since
Darwin’s discovery, the beasts of the field, the fowl of the air and
the fish of the sea have been examined with infinite pains by hundreds
of workers in the effort to trace our physical genealogy, and with
consummate success; yet few and far between have been the efforts to find
the origins of intellect and trace its progress up to human faculty. And
none of them has achieved any secure success.
It may be premature to try again, but a somewhat extended series of
studies of the intelligent behavior of fishes, reptiles, birds and
mammals, including the monkeys, which it has been my lot to carry out
during the last five years, has brought results which seem to throw light
on the problem and to suggest its solution.
Experiments have been made on fishes, reptiles, birds and various
mammals, notably dogs, cats, mice and monkeys, to see how they learned
to do certain simple things in order to get food. All these animals
manifest fundamentally the same sort of intellectual life. Their learning
is after the same general type. What that type is can be seen best from
a concrete instance. A monkey was kept in a large cage. Into the cage
was put a box, the door of which was held closed by a wire fastened to
a nail which was inserted in a hole in the top of the box. If the nail
was pulled up out of the hole, the door could be pulled open. In this
box was a piece of banana. The monkey, attracted by the new object,
came down from the top of the cage and fussed over the box. He pulled
at the wire, at the door, and at the bars in the front of the box. He
pushed the box about and tipped it up and down. He played with the nail
and finally pulled it out. When he happened to pull the door again, of
course it opened. He reached in and got the food inside. It had taken
him 36 minutes to get in. Another piece of food being put in and the
door closed, the occurrences of the first trial were repeated, but there
was less of the profitless pulling and tipping. He got in this time in
2 minutes and 20 seconds. With repeated trials the animal finally came
to drop entirely the profitless acts and to take the nail out and open
the door as soon as the box was put in his cage. He had, we should say,
learned to get in.
The process involved in the learning was evidently a process of
selection. The animal is confronted by a state of affairs or, as we may
call it, a ‘situation.’ He reacts in the way that he is moved by his
innate nature or previous training to do, by a number of acts. These
acts include the particular act that is appropriate and he succeeds. In
later trials the impulse to this one act is more and more stamped in,
this one act is more and more associated with that situation, is selected
from amongst the others by reason of the pleasure it brings the animal.
The profitless acts are stamped out; the impulses to perform them in
that situation are weakened by reason of the positive discomfort or the
absence of pleasure resulting from them. So the animal finally performs
in that situation only the fitting act.
Here we have the simplest and at the same time the most widespread sort
of intellect or learning in the world. There is no reasoning, no process
of inference or comparison; there is no thinking about things, no putting
two and two together; there are no ideas—the animal does not think of
the box or of the food or of the act he is to perform. He simply comes
after the learning to feel like doing a certain thing under certain
circumstances which before the learning he did not feel like doing. Human
beings are accustomed to think of intellect as the power of having and
controlling ideas and of ability to learn as synonymous with ability to
have ideas. But learning by having ideas is really one of the rare and
isolated events in nature. There may be a few scattered ideas possessed
by the higher animals, but the common form of intelligence with them,
their habitual method of learning, is not by the acquisition of ideas,
but by the selection of impulses.
Indeed this same type of learning is found in man. When we learn to drive
a golf ball or play tennis or billiards, when we learn to tell the price
of tea by tasting it or to strike a certain note exactly with the voice,
we do not learn in the main by virtue of any ideas that are explained
to us, by any inferences that we reason out. We learn by the gradual
selection of the appropriate act or judgment, by its association with the
circumstances or situation requiring it, in just the way that the animals
do.
From the lowest animals of which we can affirm intelligence up to man
this type of intellect is found. With it there are in the mammals obscure
traces of the ideas which come in the mental life of man to outweigh
and hide it. But it is the basal fact. As we follow the development of
animals in time, we find the capacity to select impulses growing. We find
the associations thus made between situation and act growing in number,
being formed more quickly, lasting longer and becoming more complex
and more delicate. The fish can learn to go to certain places, to take
certain paths, to bite at certain things and refuse others, but not much
more. It is an arduous proceeding for him to learn to get out of a small
pen by swimming up through a hole in a screen. The monkey can learn to do
all sorts of things. It is a comparatively short and easy task for him
to learn to get into a box by unhooking a hook, pushing a bar around and
pulling out a plug. He learns quickly to climb down to a certain place
when he sees a letter T on a card and to stay still when he sees a K. He
performs the proper acts nearly as well after 50 days as he did when they
were fresh in his mind.
This growth in the number, speed of formation, permanence, delicacy and
complexity of associations possible for an animal reaches its acme in the
case of man. Even if we leave out of question the power of reasoning,
the possession of a multitude of ideas and abstractions and the power of
control over impulses, purposive action, man is still the intellectual
leader of the animal kingdom by virtue of the superior development
in him of the power of forming associations between situations or
sense-impressions and acts, by virtue of the degree to which the mere
learning by selection possessed by all intelligent animals has advanced.
In man the type of intellect common to the animal kingdom finds its
fullest development, and with it is combined the hitherto nonexistent
power of thinking about things and rationally directing action in accord
with thought.
Indeed it may be that this very reason, self-consciousness and
self-control which seem to sever human intellect so sharply from that
of all other animals are really but secondary results of the tremendous
increase in the number, delicacy and complexity of associations which the
human animal can form. It may be that the evolution of intellect has no
breaks, that its progress is continuous from its first appearance to its
present condition in adult civilized human beings. If we could prove that
what we call ideational life and reasoning were not new and unexplainable
species of intellectual life but only the natural consequences of an
increase in the number, delicacy, and complexity of associations of
the general animal sort, we should have made out an evolution of mind
comparable to the evolution of living forms.
In 1890 William James wrote, “The more sincerely one seeks to trace the
actual course of psychogenesis, the steps by which as a race we may have
come by the peculiar mental attributes which we possess, the more clearly
one perceives ‘the slowly gathering twilight close in utter dark.’” Can
we perhaps prove him a false prophet? Let us first see if there be any
evidence that makes it probable that in some way or another the mere
extension of the animal type of intellect has produced the human sort. If
we do, let us proceed to seek a possible account of _how_ this might have
happened, and finally to examine any evidence that shows this possible
‘how’ to have been the real way in which human reason has evolved.
It has already been shown that in the animal kingdom there is, as we
pass from the early vertebrates down to man, a progress in the evolution
of the general associative process which practically equals animal
intellect, that this progress continues as we pass from the monkeys to
man. Such a progress is a real fact; it does exist as a possible _vera
causa_; it is thus at all events better than some imaginary cause of the
origin of human intellect, the very existence of which is in doubt. In a
similar manner we know that the neurones, which compose the brain and the
connections between which are the physiological parallels of the habits
that animals form, show, as we pass down through the vertebrate series,
an evolution along lines of increased delicacy and complexity. That an
animal associates a certain act with a certain felt situation means that
he forms or strengthens connections between certain cells. The increase
in number, delicacy and complexity of cell structures is thus the basis
for an increase in the number, delicacy and complexity of associations.
Now the evolution noted in cell structures affects man as well as the
other vertebrates. He stands at the head of the scale in that respect as
well. May not this obvious supremacy in the animal type of intellect and
in the adaption of his brain to it be at the bottom of his supremacy in
being the sole possessor of reasoning?
This question becomes more pressing if we realize that we must have some
sort of brain correlate for ideational life and reasoning. Some sort of
difference in processes in the brain must be at the basis of the mental
differences between man and the lower animals, we should all admit. And
it would seem wise to look for that difference amongst differences which
really do or at least may exist. Now the most likely brain difference
between man and the lower animals for our purpose, to my mind indeed the
only likely one, is just this difference in the fineness of organization
of the cell structures. If we could show with any degree of probability
how it might account for the presence of ideas and of reasoning, we
should at least have the satisfaction of dealing with a cause actually
known to exist.
The next important fact is that the intellect of the infant six months
to a year old is of the animal sort, that ideational and reasoning
life are not present in his case, that the only obvious intellectual
difference between him and a monkey is in the quantity and quality of
the associations formed. In the evolution of the infant’s mind to its
adult condition we have the actual transition within an individual from
the animal to the human type of intellect. If we look at the infant and
ask what is in him to make in the future a thinker and reasoner, we must
answer either by invoking some mysterious capacity, the presence of which
we cannot demonstrate, or by taking the difference we actually do find.
That is the difference in the quality and quantity of associations of the
animal sort. Even if we could never see how it came to cause the future
intellectual life, it would seem wiser to believe that it did than to
resort to faith in mysteries. Surely there is enough evidence to make it
worth while to ask our second question, “How might this difference cause
the life of ideas and reasoning?”
To answer this question fully would involve a most intricate treatment of
the whole intellectual life of man, a treatment which cannot be attempted
without reliance on technical terms and psychological formulas. A fairly
comprehensible account of the general features of such an answer can,
however, be given. The essential thing about the thinking of the animals
is that they feel things in gross. The kitten who learned to respond
differently to the signals, “I must feed those cats” and “I will not
feed them,” felt each signal as a vague total, including the tone, the
movements of my head, etc. It did not have an idea of the sound of _I_,
another of the sound of _must_, another of the sound _feed_, etc. It did
not turn the complex impression into a set of elements, but felt it, as I
have said, in gross. The dog that learned to get out of a box by pulling
a loop of wire did not feel the parts of the box separately, the bolt as
a definite circle of a certain size, did not feel his act as a sum of
certain particular movements. The monkey who learned to know the letter
K from the letter Y did not feel the separate lines of the letter, have
definite ideas of the parts. He just felt one way when he saw one total
impression and another way when he saw another.
Strictly human thinking, on the contrary, has as its essential
characteristic the breaking up of gross total situations into feelings
of particular facts. When in the presence of ten jumping tigers we not
only feel like running, but also feel the number of tigers, their color,
their size, etc. When, instead of merely associating some act with some
situation in the animal way, we think the situation out, we have a set
of particular feelings of its elements. In some cases, it is true, we
remain restricted to the animal sort of feelings. The sense impressions
of suffocation, of the feeling of a new style of clothes, of the pressure
of 10 feet of water above us, of malaise, of nausea and such like remain
for most of us vague total feelings to which we react and which we feel
most acutely but which do not take the form of definite ideas that we can
isolate or combine or compare. Such feelings we say are not parts of our
real intellectual life. They _are_ parts of our intellectual life if we
mean by it the mental life concerned in learning, but they are not if we
mean by it the life of reasoning.
Can we now see how the vague gross feelings of the animal sort might turn
into the well-defined particular ideas of the human sort, by the aid of a
multitude of delicate associations?
It seems to be a general law of mind that any mental element which occurs
with a number of different mental elements, appears, that is, in a number
of different combinations, tends to thereby acquire an independent life
of its own. We show children six lines, six dots, six peas, six pieces
of paper, etc., and thus create the definite feeling of sixness. Out of
the gross feelings of a certain number of lines, of dots, etc., we evolve
the definite elementary feeling of sixness by making the ‘six’ aspect of
the situations appear in a number of different connections. We learn to
feel whiteness as a definite idea by seeing white paper, white cloth,
white eggs, white plates, etc. We learn to feel the meaning of _but_ or
_in_ or _notwithstanding_ by feeling the meanings of many total phrases
containing each of them. Now in this general law by which different
associates for the same elementary process elevate it out of its position
as an undifferentiated fragment of a gross total feeling, we have, I
think, the manner in which the vague feelings of the nine-months-old
infant become the definite ideas of the five-year-old boy, the manner in
which in the race the animal mind has evolved into the human, and the
explanation of the service performed by the increase in the delicacy of
structure of the human brain and the consequent increase in the number of
associations.
The bottle to the six-months-old infant is a vague sense-impression which
the infant does not think about or indeed in the common meanings of the
words perceive or remember or imagine. Its presence does not arouse
ideas, but action. It is not to him a thing so big, or so shaped, or so
heavy, but is just a vaguely sizable thing to be reached for, grabbed and
sucked. Like the lower animals, with the exception that as he grows a
little older he reacts in very many more ways, the child feels things in
gross in a way to lead to direct reactions. Vague sense-impressions and
impulses make up his mental life. The bottle, which to a dog would be a
thing to smell at and paw, to a kitten a thing to smell at and perhaps
worry, is to the child a little later a thing to grab and suck and turn
over and drop and pick up and pull at and finger and rub against its toes
and so on. The sight of the bottle thus becomes associated with many
different reactions, and thus by our general law tends to gain a position
independent of any of them, to evolve from the condition of being a
portion of the cycles see-grab, see-drop, see-turn over, etc., to the
condition of being a definite idea.
The increased delicacy and complexity of the cell structures in the human
brain give the possibility of very small parts of the brain-processes
forming different connections, allow the brain to work in very great
detail, provide processes ready to be turned into definite ideas. The
great number of associations which the human being forms furnish the
means by which this last event is consummated. The infant’s vague
feelings of total situations are by virtue of the detailed working of
his brain all ready to split up into parts, and his general activity and
curiosity provide the multitude of different connections which allow them
to do so. The dog, on the other hand, has few or no ideas because his
brain acts in coarse fashion and because there are few connections with
each single process.
When once the mind begins to function by having definite ideas, all the
phenomena of reasoning soon appear. The transition from one idea to
another is the feeling of their relationship, of similarity or difference
or whatever it may be. As soon as we find any words or other symbols to
express such a feeling, or to express our idea of an action or condition,
we have explicit judgments. Observation of any child will show us that
the mind cannot rest in a condition where it has a large body of ideas
without comparing them and thinking about them. The ideas carry within
them the forces that make abstractions, feelings of similarity, judgments
and other characteristics of reasoning.
In children two and three years of age we find all these elements of
reasoning present and functioning. The product of children’s reasoning
is often irrational, but the processes are all there. The following
instances from a collection of children’s sayings by Mr. H. W. Brown show
children making inductions and deductions after the same general fashion
as adults:—
(2 yrs.) T. pulled the hairs on his father’s wrist. Father.
“Don’t, T., you hurt papa!” T. “It didn’t hurt grandpa.”
(2 yrs. 5 mos.) M. said, “Gracie can’t walk, she wears little
bits of shoes; if she had mine, she could walk. When I get some
new ones, I’m going to give her these, so she can walk.”
(2 yrs. 9 mos.) He usually has a nap in the forenoon, but
Friday he did not seem sleepy, so his mother did not put him
to bed. Before long he began to say, “Bolly’s sleepy; mamma
put him in the crib!” This he said very pleasantly at first;
but, as she paid no attention to him, he said, “Bolly cry, then
mamma will.” And he sat down on the floor and roared.
(3 yrs.) It was between five and six in the afternoon; the
mother was getting the baby asleep. J. had no one to play with.
He kept saying, “I wish R. would come home; mamma, put baby
to bed, so R. will come home.” I usually get home about six,
and as the baby is put to bed about half-past five, he had
associated the one with the other.
(3 yrs.) W. likes to play with oil paints. Two days ago my
father told W. he must not touch the paints any more, for he
was too small. This morning W. said, “When my papa is a very
old man, and when I am a big man and don’t need any papa, then
I can paint, can’t I, mamma?”
(3 yrs.) G.’s aunt gave him ten cents. G. went out, but soon
came back saying, “Mamma, we will be rich now.” “Why so, G.?”
“Because I planted my ten cents, and we will have lots of ten
cents growing.”
(3 yrs.) B. climbed up into a large express wagon, and would
not get out. I helped him out, and it was not a minute before
he was back in the wagon. I said, “B., how are you going to get
out of there now?” He replied, “I can stay here till it gets
little, and then I can get out my own self.”
(3 yrs.) F. is not allowed to go to the table to eat unless she
has her face and hands washed and her hair combed. The other
day she went to a lady visiting at her house and said, “Please
wash my face and hands and comb my hair; I am very hungry.”
(3 yrs.) If C. is told not to touch a certain thing, that it
will bite him, he always asks if it has a mouth. The other day
he was examining a plant, to see if it had a mouth. He was told
not to break it, and he said, “Oh, it won’t bite, because I
can’t find any mouth.”
Nowhere in the animal kingdom do we find the psychological elements of
reasoning save where there is a mental life made up of the definite
feelings which I have called ‘ideas,’ but they spring up like magic
as soon as we get in a child a body of such ideas. If we have traced
satisfactorily the evolution of a life of ideas from the animal life of
vague sense-impressions and impulses, we may be reasonably sure that no
difficulty awaits us in following the life of ideas in its course from
the chaotic dream of early childhood to the logical world-view of the
adult scientist.
In a very short time we have come a long way, from the simple learning of
the minnow or chick to the science and logic of man. The general frame
of mind which one acquires from the study of animal behavior and of the
mental development of young children makes our hypothesis seem vital and
probable. If the facts did eventually corroborate it, we should have an
eminently simple genesis of human faculty, for we could put together the
gist of our contention in a few words. We should say:—
“The function of intellect is to provide a means of modifying our
reactions to the circumstances of life, so that we may secure pleasure,
the symptom of welfare. Its general law is that when in a certain
situation an animal acts so that pleasure results, that act is selected
from all those performed and associated with that situation, so that,
when the situation recurs, the act will be more likely to follow than
it was before; that on the contrary the acts which, when performed in a
certain situation, have brought discomfort, tend to be dissociated from
that situation. The intellectual evolution of the race consists in an
increase in the number, delicacy, complexity, permanence and speed of
formation of such associations. In man this increase reaches such a point
that an apparently new type of mind results, which conceals the real
continuity of the process. This mental evolution parallels the evolution
of the cell structures of the brain from few and simple and gross to many
and complex and delicate.”
Nowhere more truly than in his mental capacities is man a part of nature.
His instincts, that is, his inborn tendencies to feel and act in certain
ways, show throughout marks of kinship with the lower animals, especially
with our nearest relatives physically, the monkeys. His sense-powers
show no new creation. His intellect we have seen to be a simple though
extended variation from the general animal sort. This again is presaged
by the similar variation in the case of the monkeys. Amongst the minds of
animals that of man leads, not as a demigod from another planet, but as a
king from the same race.
FOOTNOTES
[1] ‘Animal Intelligence: An Experimental Study of the Associative
Processes in Animals’ (’98), ‘The Instinctive Reactions of Young Chicks’
(’99), ‘A Note on the Psychology of Fishes’ (’99), and ‘The Mental Life
of the Monkeys’ (’01). I have added a theoretical paper, ‘The Evolution
of the Human Intellect,’ which appeared in the _Popular Science Monthly_
in 1901, and which was a direct outgrowth of the experimental work. I am
indebted to the management of the _Psychological Review_, and that of the
_American Naturalist_ and _Popular Science Monthly_, for permission to
reprint the three shorter papers.
[2] Unless one assumes telepathic influences.
[3] Reason in Common Sense, p. 154 ff.
[4] This chapter originally appeared as Monograph Supplement No. 8 of the
Psychological Review.
[5] I do not mean that scientists have been too credulous with regard
to spiritualism, but am referring to the cases where ten or twenty
scientists have been sent to observe some trick-performance by a
spiritualistic ‘medium,’ and have all been absolutely confident that they
understood the secret of its performance, _each of them giving a totally
different explanation_.
[6] The phrase ‘practically utter hunger’ has given rise to
misunderstandings. I have been accused of experimenting with starving or
half-starved animals, with animals brought to a state of fear and panic
by hunger, and the like!
The desideratum is, of course, to have the motive as nearly as possible
of equal strength in each experiment with any one animal with any one
act. That is, the animal should be as hungry at the tenth or twentieth
trial as at the first. To attain this, the animal was given after each
‘success’ only a very small bit of food as a reward (say, for a young
cat, one quarter of a cubic centimeter of fish or meat) and tested not
too many times on any one day. ‘Utter hunger’ means that no diminution in
his appetite was noted and that at the close of the experiment for the
day he would still eat a hearty meal. After the experiments for the day
were done, the cats received abundant food to maintain health, growth and
spirits, but commonly somewhat less than they would of their own accord
have taken. No one of the many visitors to the room mentioned anything
extraordinary or distressful in the animals’ condition. There were no
signs of fear or panic.
Possibly I was wrong in choosing the term ‘utter hunger’ to denote the
hunger of an animal in good, but not pampered, condition and without food
for fourteen hours. It is not sure, however, that the term ‘utter hunger’
is inappropriate. The few reports made of experiments in going without
food seem to show that, in health, the feeling of hunger reaches its
maximum intensity very early. It is of course not at all the same thing
as the complex of discomforts produced by long-continued insufficiency of
food. Hunger is not at all a synonym for starvation.
[7] The experiments now to be described were for the most part made in
the Psychological Laboratory of Columbia University during the year
’97-’98, but a few of them were made in connection with a general
preliminary investigation of animal psychology undertaken at Harvard
University in the previous year.
[8] No. 7 hit the string in his general struggling, apparently utterly
without design. He did not realize that the door was open till, two
seconds after it had fallen, he happened to look that way.
[9] No. 6, in trying to crawl out at the top of the box, put its paw in
above the string. It fell down and thus pulled the string. It did not
claw at it, and it was 16 seconds before it noticed that the door was
open. In all the other times that it escaped the movement was made in the
course of promiscuous scrambling, never in anything like the same way
that No. 2 made it.
[10] No. 3 did not go out until 12 seconds had elapsed after it had
pulled the string.
[11] The back of the pen adjoined the elevator shaft, being separated
from it by a partition 33 inches high. No. 2 heard the elevator coming up
and put his paws up on the top of this partition so as to look over. In
so doing he knocked the fastening of the cord at that end and opened the
door. He did not turn to come out, and I shut the door again.
[12] FF was a box 40 × 21 × 24 inches, the door of which could be opened
by putting the paw out between the bars to its right and pulling a loop
which hung 16 inches above the floor, 4 inches out from the box and 6
inches to the right of the door.
[13] KKK was box K with both bolts removed. All that had to be done was
to poke the paw out at one side of the door and press down a little bar
of wood.
[14] The cats and chick were left in for two minutes at each trial, the
dogs for from one to one and a half minutes.
[15] One result of the application of experimental method to the study of
the intellect of animals was the distinction of learning by the selection
of impulses or acts from learning by the selection of ideas. The usual
method of learning in the case of animals other than man was shown by
the studies reprinted in this volume to be the direct selection, in a
certain situation, of a desirable response and its association with that
situation, not the indirect selection of such a response by the selection
of some _idea_ which then of itself produced the response. The animals
did not usually behave as if they _thought of_ getting freedom or food
in a certain way and were thereby moved to do so, but as if the stimulus
in question made immediate connection with the response itself or an
intimately associated impulse.
The experiments had in this respect both a negative or destructive and
a positive or constructive meaning. On the one hand, they showed that
animal learning was not homologous with human association of ideas; that
animal learning was not human learning _minus_ abstract and conceptual
thought, but was on a still ‘lower’ level. On the other hand, the first
positive evidence that animals could, under certain circumstances, learn,
as man so commonly does, by the indirect connection of a response with a
situation through some non-sensory relic or representative of the latter,
came from my experiments.
It was perhaps natural that the more exciting denial of habitual learning
by ideas should have attracted more attention than the somewhat tedious
experiments to prove that under certain conditions they could so learn.
At all events, a perverse tradition seems to have grown up to the effect
that I denied the possibility of animals having images or learning in any
case by representative thinking.
There is some excuse for this tradition in the fact that whereas the
proof that the habitual learning of these dogs and cats did not require
‘ideas’ is clear and emphatic, my evidence that certain features of their
behavior _did_ require ‘ideas’ is complicated and imperfect.
The fact seems to be that a ‘free idea’ comes in the animals or in
man only as a result of a somewhat elaborate process of analysis or
extraction from a gross total sensory process. The primary level or grade
of experience, common to animals and little babies, comprises states
of mind such as an adult man gets if lost in anger, fear, suffocation,
dyspepsia, looking at a panorama of unknown objects with head upside
down, smelling the mixture of odors of a soap factory, driving a golf
ball, dashing to the net in a game of tennis, warding off a blow, or
swimming under water. For a man to get a distinct controllable percept of
approaching asthma, of a carpet loom seen upside down, or of a successful
‘carry through,’ or ‘smash’ or ‘lob,’ so that one knows just what one is
experiencing or doing, and can recall just what one experienced or did,
requires further experience of the element in question—contemplation of
it in isolation or dealings with it in many varied connections. So for
a cat to get a distinct controllable percept of a loop, or of its own
clawing or nosing or pulling, it must have the capacity to analyze such
elements out of the total gross complexes in which they inhere, and also
certain means or stimuli to such analysis.
This capacity or tendency the cats and dogs do, in my opinion, possess,
though in a far less degree than the average child. They also suffer from
lack of stimuli to the exercise of the capacity. Their confinement, for
the most part, to the direct sensory experience of things and acts, is
due in part to the weakness of the capacity or tendency of their neurones
to act in great detail, and in part to the lack of such stimuli as visual
exploration of things in detail, manual manipulation of the same thing
in many ways, and the identification of elements of objects and acts by
language. They get few free ideas because they are less ready than man to
get them under the same conditions and because their instinctive behavior
and social environment offer conditions that are less favorable. The task
of getting an animal to have some free ideational representative of a red
loop or of pushing up a button with the nose may be compared with that
of getting a very stupid boy to have a free ideational representative of
acceleration, or of the act of sounding _th_. The difference between them
and man which is so emphasized in the text, though real and of enormous
practical importance, is thus not at all a mysterious gap or trackless
desert. We can see our way from animal to human learning.
[16] A man may learn to swim from the general feeling, “I want to be
able to swim.” While learning, he may think of this desire, of the
difficulties of the motion, of the instruction given him, or of anything
which may turn up in his mind. This is all extraneous and is not
concerned in the acquisition of the association. Nothing like it, of
course, goes on in the animal’s mind. Imagine a man thrown into the water
repeatedly, and gradually floundering to the shore in better and better
style until finally, when thrown in, he swims off perfectly, and deprive
the man of all extraneous feelings, and you have an approximate homologue
of the process in animals. He feels discomfort, certain impulses to
flounder around, some of which are the right ones to move his body to
the shore. The pleasure which follows stamps in these, and gradually the
proper movements are made immediately on feeling the sense-impression of
surrounding water.
[17] See 10 in A, 3 in A, 10 in D; 10 in C, 4 in C, 3 in C; 6, 2, 5, 4 in
E; 4 in F; 10 in H, 3 in H; 3, 4, 5, in I; 4 in G, 3 in G; 3 in K; 10 in
L; dog 1 in N and CC; dog 1 in G and O.
[18] This chapter appeared originally in the _Psychological Review_, Vol.
VI, No. 3.
[19] This double rating is necessary because of the fact that the chick
often gives several distinct pecks in a single reaction. The ‘times
reacted to’ mean the number of different times that the chicks noticed
the color.
[20] The crude experiments reported in this and the preceding paragraphs
were not made to test the presence of color vision proper, that is,
of differentiation of two colors of the same brightness, but only to
ascertain how chicks reacted to ordinary colored objects. It was,
however, almost certain from the relative frequency of the reactions that
the intensity factor was not the cause of the response. For example, if
it had been, black on white and yellow on black should have been pecked
at oftener.
[21] This chapter appeared originally in the _American Naturalist_, Vol.
XXXIII, No. 396.
[22] This chapter appeared originally as Monograph Supplement No. 15 to
the _Psychological Review_.
[23] Pp. 20 to 155 of this volume.
[24] _American Journal of Psychology_, Vol. X, pp. 256-279; Vol. XI, pp.
80-100, 131-165; Vol. XII, pp. 206-239.
[25] Practically a memory trial of CC, done January 21, 1900.
[26] Did it by pulling door and thus shaking lever.
[27] Practically a memory trial of SS.
[28] Did it by pulling door and biting wire.
[29] This, I regret, was not done [E. L. T., 1911].
[30] The acts and the number of chances to see me do each and the results
were as follows; details can be found on the table on page 226. F =
failed after tuition.
No. 1.—MM 21 F
Theta 5 F
QQ 10 F
RR 4 F
W 9 did in .22
Delta 15 F
Epsilon 40 F
QQ (f) 15 F
QQ (c) 1 did in 2.20
No. 3.—Theta 25 did in 3.00.
QQ 40 F
Gamma 30 F
Epsilon 25 F
QQ (ff) 5 F
QQ (c) 20 F, did in 1.30, F, 5 F, 5 F
QQ (e) 5 F, did in 2.00
[31] He did push it once with his nose.
[32] I inadvertently pulled the nail out in one of five cases when I was
fingering it to see if attracting his attention to it would lead to the
act.
[33] Not significant. Due to inattention. Was temporary.
[34] Pulled wire and door.
[35] Pushed with head by chance.
[36] Reached in at 9:30 and took out the banana, which I replaced.
[37] Did by constant pulling at the door.
[38] Did touch nail four times.
[39] Did by pulling hard on wire (not loop); the loop got loose from nail.
[40] Did by pulling at the door till the bar was worked around.
[41] The ‘say,’ may be replaced by some bodily attitude, facial
expression, or other verbal formula that identifies the situation as one
to be responded to by speech.
[42] This would, of course, result from a well-known corollary of the
laws of habit.
[43] In _Essays Philosophical and Psychological in Honor of William
James_, pp. 591-599.
[44] Professor Smith’s own experiments illustrate this.
[45] Biological Lectures from the Marine Biological Laboratory of Woods
Holl, 1898, p. 323 ff.
[46] This chapter appeared originally in the _Popular Science Monthly_,
Nov., 1901.
INDEX
Abstraction, 120.
_See also_ Reasoning.
Action-system, importance of the study of the, 15 f.;
of monkeys, 190 f., 237.
Anecdotal school in animal psychology, 23 ff., 151 f.
Apparatus, descriptions of, 29 ff., 56 ff., 61 f., 169 f., 177 ff.,
196 ff.
Assimilation, 249 f.
Association, as a problem in animal psychology, 20 ff.;
by similarity, 116 ff.;
complexity of, 132 ff.;
conditions of, 43 ff.;
delicacy of, 128 ff., 195 ff.;
development of, in the animal kingdom, 285 ff.;
in cats, 38 ff.;
in chicks, 63 f.;
in dogs, 56 ff.;
in fishes, 169 ff.;
in man, 123 ff., 127, 285;
in monkeys, 182 ff., 194 f., 209 ff.;
in relation to attention, 44 ff.;
to individual differences, 52 ff.;
to inhibition, 142 ff.;
to instincts, 36 f., 142 ff.;
to previous experience, 48 ff.;
number of connections formed by, 135 ff.;
permanence of connections formed by, 138 ff., 194 f., 203 f.;
progress of, measurable by time-curves, 28, 40, 42;
the mental fact in, 98 ff.;
without ideas, 101 f., 127, 209 ff.
_See also_ Associations and Learning.
Associations, complexity, 132 ff.;
delicacy, 128 ff., 195 ff.;
number, 121, 135 ff.;
permanence, 138 ff., 194 f., 203 f.
Associative memory. _See_ Association.
Attention, 144 ff.;
and association, 44 ff.;
to imposed movements, 103 ff.
Behavior, acquired tendencies to, 244 ff. (_see also_ Association);
evolution of, 272 ff.;
general laws of, 241 ff.;
indefiniteness of the term, 5;
of cats, 35 ff., 88 f., and _passim_;
of chicks, 63 f., 138, 143 f., 156 ff., and _passim_;
of dogs, 59 ff., 92 ff.;
of fishes, 169 ff.;
of monkeys, 182 ff.;
original tendencies to, 242 f. (_see also_ Instincts);
predictability of, 241 f.;
proposed simplification of the laws of, 265 ff.;
_versus_ consciousness as an object of study, 1 ff.
_See also_ Association, Instincts, Learning, Memory, etc.
BOSWORTH, F. D., 240.
Cats, associative processes in, 35 ff.;
imitation in, 85 ff.;
the presence of ideas in, 100 ff.;
reasoning in, 67 ff.
Chicks, associative processes in, 61 ff.;
imitation in, 81 ff.;
instincts of, 156 ff.
Complexity, of associations, 132 ff.
Concepts, 116 ff.
Connection-systems, action of, in association, 246 ff., 266;
importance of the study of, 16 f.
Consciousness, amenability of, to scientific study, 7 ff.;
as pure experience, 13 f.;
as studied by the one who has or is it, 10 ff.;
of animals, 25 f., 67 ff., 98 ff., 123, 146 f., and _passim_;
social, 146 f.;
space-relations of, 14;
_versus_ behavior as an object of study, 1 ff.
Coördinations, of chicks, 160 ff.
DEAN, B., 161.
Delicacy of association, 128 ff., 195 ff.
DEWEY, J., 6.
Differences, between species of animals in the associative processes,
64 ff.
Discomfort, as an influence in learning, 245 ff.
Discrimination, in cats and dogs, 128 ff.;
in chicks, 156 ff.;
in monkeys, 195 ff.
Dogs, associative processes in, 56 ff.;
imitation in, 91 ff.;
the presence of ideas in, 115 f.;
reasoning in, 67 ff.
Education, applications of animal psychology in, 149 f.
Effect, the law of, 244 f., 266 ff.
Emotional reactions of chicks, 162 ff.
Evolution, of behavior, 272 ff.;
of human intellect, 282 ff.;
of ideas, 289 ff.
Exercise, the law of, 244 f.
Experience, the influence of previous, 48 ff.
Experiments, need of, in animal psychology, 26;
with cats, 35 ff., 85 ff., 103 ff., 111 f., 114 f., 129 ff., 138 f.;
with chicks, 61 ff., 81 ff., 132, 136, 143 f., 156 ff.;
with dogs, 56 ff., 91 ff., 103 ff., 115 f.;
with fishes, 169 ff.;
with monkeys, 176-235, _passim_.
Fears, of chicks, 162 ff.
Fishes, experiments with, 169 ff.
GALTON, F., 3.
Habit. _See_ Association.
HALL, G. S., 3.
Human. _See_ Man.
Hunger, effect of, on animal learning, 27 f.
HUNT, H. E., 163.
Ideas, development of, 121 f., 289 ff.;
existence of, as adjuncts in animal learning, 108 ff., 189 ff., 206
ff., 222 ff.;
impotence of, to create connections, 257 ff.
Ideo-motor action, 257 ff.
Images, 108 f. _See also_ Ideas.
Imitation, analysis of the supposed effects of, 251 ff.;
in cats, 85 ff.;
in chicks, 81 ff.;
in dogs, 91 ff.;
in general, 76 ff., 94 ff.;
in monkeys, 96, 211 ff., 219 ff.;
in speech, 253 ff.
Impulses, as features of the associative processes, 100 ff.;
defined, 37.
Incubation, the instinct of, 276 ff.
Individual differences in association, 52 ff.
Inhibition of instincts by association, 142 ff.
Instincts, as explanations of some cases of supposed imitation, 251;
inhibition of, 142 ff.;
of chicks, 156 ff.;
of incubation, 276 ff.;
of monkeys, 237;
the starting-point of animal learning, 36 f.
Intellect. _See_ Association, Ideas, Imitation, Memory, Reasoning,
etc.
Interaction, 147 f.
Introspection, the over-emphasis of, 3.
JAMES, W., 3, 120, 143, 286.
JENNINGS, H. S., 267, 268, 269, 270, 274, 279.
KLINE, L. W., 173.
Language, 253 ff.
Learning, evolution of, 278 ff.;
methods of, 174 f.
_See_ Association, Behavior, Ideas, Imitation, Reasoning.
LUBBOCK, J., 240.
Man, compared with lower animals in intellect, 123 ff., 239 f.;
mental evolution of, 282 ff.
Memory, 108 f., 138 ff., 203.
_See_ Association and Permanence of associations.
Methods in animal psychology, 22 ff.
MILLS, W., 191.
Monkeys, 172 ff.;
associative processes in, 182 ff.;
differences from lower mammals, 189 ff., 204 ff., 237 ff.;
general mental development of, 236 ff.;
imitation of man by, 211 ff.;
imitation of other monkeys by, 219 ff.;
possible mental degeneracy of, 151;
presence of ideas in, 189 ff., 206 ff., 222 ff.;
reasoning in, 184 ff.
MORGAN, C. L., 3, 80, 99 f., 101, 119, 120, 125 f., 146, 147, 162,
165 f.
Motives, used in the experiments, 26 ff.;
defined, 38.
Number of associations, 135 ff.;
as a cause of the development of free ideas, 121 f.
PECKHAM, G. W. and E. G., 240.
Pecking, accuracy of, in chicks, 159 f.
Pedagogy, applications of animal psychology to, 149 f.
Permanence of associations, 138 ff., 203.
Predictability of behavior, 241 f.
Primates. _See_ Monkeys.
Reasoning, 118 f.;
and free ideas, 291 ff.;
as a consequence of the laws of exercise and effect, 263 ff.;
in cats and dogs, 67 ff.;
in monkeys, 184 ff.
Recepts, 120.
Resolution, Jennings’ law of, 267 ff.
Responses to situations as the general form of behavior, 242 ff., 283
f.
ROMANES, G. J., 68 f., 70, 80.
SANTAYANA, G., 6, 18 f.
Satisfaction, the influence of, in learning, 147 f., 244 f.;
the nature of, 245 f.
Situation and response as the general form of behavior, 242 ff., 283
ff.
SMALL, W. S., 173.
SMITH, S., 269 f., 280.
Social consciousness of animals, 146 f.
SPALDING, D. A., 162, 163, 165.
STOUT, G. F., 3.
Swimming, by chicks, 161 f.
Time of achievement as a measure of the closeness of association,
28, 40, 42, 54.
Time-curves, 38 ff., 57 ff., 65, 185 f.;
as evidence against the existence of reasoning, 73 f.
TITCHENER, E. B., 2.
Vigor, as a factor in learning, 46.
WHITMAN, C. O., 275 ff.
YERKES, R. M., 240.
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