The Act of Creation (81 page)

 

 

 

The Cat in the Box

 

 

The cat in the puzzle box, in Thorndike's classic experiments, is also
put into a situation so designed that it can be solved only by trial
and error. The box is equipped with contrivances such as rings, loops,
turning bolts, pedal boards, etc., and with a door which opens, according
to the experiment, when the animal operates one of these contrivances,
or several of them in a given order. Thus the cat may have to turn bolt B
which, however, becomes loose only after bolt A has already been turned;
or it may have to pull a string, or a loop, in order to free itself. When
the cat is put into the box, it 'tries to squeeze through any opening;
it claws or bites at the bars or wire; it thrusts its paws out through
any opening, and claws at everything it reaches; it continues its efforts
when it strikes anything loose and shaky; it may claw at things within the
box. It does not pay very much attention to the food outside, but seems
simply to strive instinctively to escape from confinement. The vigour
with which it struggles is extraordinary. For eight or ten minutes it
will claw and bite and squeeze incessantly.' [30]

 

 

The cat's behaviour is typical of that phase in a 'blocked' situation,
where organized behaviour disintegrates and yields to more or less
random trials. The solution -- pushing a bolt or pulling a loop or even
licking itself -- will be first hit upon by chance, and after a number
of repetitions, it will be retained; the learning curve will be more
or less continuous or it may show a sudden, sharp drop. The objections
against this kind of experimental design are essentially the same as
against classical conditioning: they create an artificial universe. 'The
solution of Thorndike's problems demanded behaviours that were quite
beyond the animal's normal repertoire. Cats do not get out of boxes by
pressing buttons or by washing themselves; rather they try to squeeze
through narrow openings or scratch at the barriers, and Thorndike's
animals were observed attempting just such solutions as part of their
early trial and error. In other words, the correct response in a situation
like Thorndike's could only be hit upon by sheer, blind chance.' [31]

 

 

The conclusion which Thorndike and his followers drew from
these experiments -- 'that animals are incapable of higher mental
processes such as reasoning and insight -- that they are limited to the
stamping-in
and
stamping-out
mode of trial and error' -- is
one of the most astonishing examples of question-begging in the history
of modern science. One might just as well adapt Thorndike's method of
reasoning to human education, teach children nonsense syllables which
can only be learned by rote, and then conclude that children are only
capable of learning by rote. And yet, to quote Hilgard: 'for nearly half
a century one learning theory dominated all others in America, despite
numerous attacks upon it and the rise of its many rivals. It is the
theory of Edward L. Thorndike.' [32] Tolman, writing forty years after the
publication of Thorndike's
Animal Intelligence
, went even further:

 

The psychology of animal learning -- not to mention that of
child-learning -- has been and still is primarily a matter of agreeing
or disagreeing with Thorndike, or trying in minor ways to improve
upon him. Gestalt psychologists, conditioned-reflex psychologists,
sign-Gestalt psychologists -- all of us here in America seem to have
taken Thorndike, overtly or covertly, as our starting point. [32a]

 

Cat experiments of a type diametrically opposed to Thorndike's were
carried out by Adams. It is amusing to compare the description of the
behaviour of Thorndike's cats which I have just quoted, with the behaviour
of Adams' cats:

 

A piece of liver is suspended from the top of a wire-cage, so that
the liver rests on the floor inside the cage, loosely held by the
thread. A hungry cat in the room with the cage, but outside it, sees
the liver and walks over to the cage. It hesitates for a time and its
head moves up and down as though it is studying the string. Then it
jumps on top of the cage, catches the string in its mouth, raises the
liver by joint use of mouth and paw, and leaps down with the stick at
the end of the string in its mouth. [33]

 

The behaviour of Adams' cat, first 'thinking out' the solution of the
problem, then acting it out in an unhesitating, smooth, purposeful manner,
is of the same kind as Köhler's chimpanzees'. The contrast between this
type of intelligent problem-solving, and Thorndike's stamping-in process
seems to be complete. Yet the cat's learning in the box is by no means
the blind, random process which Thorndike and his followers read into
it. In the first place we must realize that the cat's handicap lies not
only, as in classical conditioning, in the
irrelevance
of the
clues which in its natural environment the cat would ignore; but also
in the fact that the clue -- say, a loop hanging from the ceiling --
is hidden or 'drowned' among other equally irrelevant clues -- latches,
bolts, etc. The unnaturalness of the tasks set in these experiments is
illustrated by the 'lick-yourself-to-escape' type of rule. Yet even in
this surrealistic universe, the cat's behaviour testifies to a remarkably
high I.Q. After the initial bewilderment, as adjustment to the laboratory
situation progresses, the range of the cat's tries will be narrowed down,
and loops, bolts, etc., will be paid an increasing mount of attention,
as members of the nascent matrix. The cat develops, like Pavlov's dogs,
an attitude of expectancy, of 'Means-End Readiness' (Tolman); it begins to
form 'hypotheses'. [34] Thus, when the cat has learned to get out of the
box by clawing at a loop, and the loop is then displaced from the front
to the rear wall of the box, it will learn to free itself much quicker
than before it had abstracted the loop-Gestalt from other clues. If,
however, the loop is replaced by a small wooden platform hung in the same
place which the loop occupied before, the animal will free itself after
a short while by striking at the platform; in this case, the location
is the clue. Thus the 'loop hypothesis' can exist side by side with the
'place hypothesis' -- just as Krechevsky's rats, who had to guess whether
the food was hidden by a door of a given colour, or of a given location,
formed first a colour hypothesis, then a place hypothesis. [35]

 

 

At this stage, the cat's behaviour can be described as a series of
'provisional tries'. [36] These tries, far from being governed by chance,
show great plasticity: if the cat has learned to escape by pu||ing a
string with its foot, it may on the next occasion free itself by pulling
the string with its teeth, which requires an entirely different sequence
of motions. Even where the 'correct' response was the perverse action
of licking its own fur, the act is reduced in the final trials 'to a
mere symbolic vestige.' [37]
Whichever way we look at it, the cat's behaviour is most fittingly -- if
somewhat metaphorically -- described as learning the rules of Thorndike's
game by a process of elimination and empirical induction. The learning
curve is a function of several variables: it will show gradual or sudden
progress, continuity and discontinuity, according to the experimental
conditions, individual learning capacity, fatigue, and chance.
NOTES
To
p. 559
. Hilgard calls Hull's system 'the most
influential of the theories between 1930 and 1950, judging from the
experimental and theoretical studies engendered by it, whether in its
defence, its amendment or its refutation' (Hilgard, 1958, p. 192).

 

 

To
p. 559
. The objection to this is not that Hull
postulated a continuous series linking rat to man, but that his 'primary
laws' are epitomized by the bar-pressing act of the rat, which he regarded
as the atomic unit of behaviour. The fallacy of this reasoning seems to
be derived from Hull's implied notion of mental progress from rat to man
as a linear gradient. Theories of this kind fail to take into account the
hierarchic principle in mental evolution -- reflected in the hierarchy
of levels in the nervous system. If instead of linear gradients, we
think in terms of levels of increasing complexity, then a difference in
degrees does become a difference in kind. Since the basic mechanisms of
sexual reproduction are common to all mammalian species, Hull's postulate
seems to imply that detailed study of sexual behaviour in the rat would
eventually yield the 'primary laws' underlying the Kinsey reports on the
sexual behaviour of the American male and female. Homologue principles
(such as the part-whole relation, or control by feedback) do operate
on all levels, but they are general principles, not specific 'units' or
'atoms' of behaviour.

 

 

To
p. 565
. Coding is an irreversible act, and
once the code is established, it will be relatively permanent -- until it
decays. If, however, the dog is fooled repeatedly and in quick succession
('massed practice'), i.e. food is withheld after the buzzer has sounded,
a negative code will superimpose itself on the previous one. The first
few times the response will stop at salivation short of chewing; but
soon it will stop short of salivation. After a few hours' rest, however,
salivation is restored by 'spontaneous recovery' -- a paradox which has
bedevilled learning theory for a long time. Perhaps the explanation may be
sought on the following lines. The whole attitude of the dog, as it has
become adapted to the laboratory situation, is based on the expectation
that all stimuli are events relevant to food; and that the negative code
(buzzer -- > no food), if it has been quickly superimposed on the
positive one (buzzer -- > food), is of a more temporary and brittle
nature than its opponent. If, however, the unrewarded signals are
spaced out over a greater length of time, i.e. if the extinction-drill
approximates in thoroughness the original drill, extinction becomes final
(Cf. e.g. Hebb, 1958, pp. 134-5, 147).

 

 

 

 

 

XIII
THE PITFALLS OF GESTALT
More about Chimpanzees
If the S.-R. theorist's method of designing experiments seems to be
aimed at printing a wiring circuit into the animal's nervous system,
Köhler's method was to provide it with a do-it-yourself kit. The main
task of the experimenter, as Köher saw it, was to arrange for
his chimpanzees conditions which favour original discovery by placing
the necessary paraphernalia in their cage -- solid and hollow sticks,
crates, etc.; and to make the task just difficult enough to exceed,
by a fraction as it were, the limit of the animal's repertory of skills.
I have mentioned a few typical examples of the chimpanzees' achievements
in Book One (
Chapter V
). In the
use
of tools
the decisive factor was the discovery that a previously
acquired playful technique M1 could be applied as a mediating performance
to solve a problem in the blocked matrix M2. Nueva applied her stick --
which previously she had used only for pushing things about in play --
to rake in a banana placed beyond her reach outside the cage. In similar
ways, the chimpanzees used sticks as jumping poles to get at fruit hung
high from the ceiling; as implements to make holes in the wire-netting
of the cage, to dig up roots in the earth or to prise open the lid of
a water-tank; they used sticks as traps to capture crowds of succulent
ants, and as weapons for stabbing at fowls and killing lizards. Each
of these new achievements was based on the combination of two or more
already existing skills, and some of them on serial sequences of 'Eureka
processes': when a chimp had discovered the use of a stick as a rake,
a short stick was then used to rake in a longer stick to rake in the
bananas.

 

 

In the
making of tools
we saw similar bisociative processes at
work. Sultan's star achievement was the fitting of two hollow bamboo-rods
together into one long rod, by pushing the end of the thinner rod into
the opening of the other. Let me describe this experiment in some detail:

 

Sultan is given the two sticks, and the banana is placed at a distance
from the bar greater than the length of each single stick. For quite
a while he tries to reach the banana with one stick or the other (M1
obstructed, random trials). He then pulls a wooden box, which has been
used in a different type of experiment, to the bar (fumbling for some
M2 to provide the 'mediating performance'). He pushes the useless box
away again, pushes one stick outside the bar on the ground as far as
it will go and prods it with the second stick towards the banana (M3:
Sultan learned long ago to push a longer stick about with a shorter
one). He succeeds in pushing the first stick into contact with the
banana, but obviously cannot pull the banana in. Nevertheless, he
repeats the procedure: when he has pushed one stick out of his reach
and it is given back to him, he starts once more. 'But although, in
trying to steer it cautiously, he puts the stick in his hand exactly
to the cut (i.e. the opening) of the stick on the ground, and although
one might think that doing so would suggest the possibility of pushing
one stick into the other, there is no indication whatever of such a
practically valuable solution [no "insight"]. Finally, the observer
[i.e. Köhler] gives the animal some help by putting one finger into the
opening under the animal's nose (without pointing to the other stick
at all). This has no effect [still no insight]; Sultan, as before,
pushed one stick with the other towards the objective. . . .

 

He finally abandons the attempt altogether. These tries have lasted
over an hour. The chimp was then left in the keeper's care, who reported
later on: