The Act of Creation (70 page)

p. 491
. The chaffinch song consists of three
distinct and well-articulated phrases. Hand-reared chaffinches produce a
much simplified, rudimentary variant of the song, where the first and
second phrase are often inseparable, and the third partly or wholly
missing. But -- and this is the elegant point of the experiment -- if
the young bird is left to be reared by its parents, then taken away and
isolated in September, that is to say, long before it starts singing, it
will nevertheless burst into normal song next spring; Apparently 'these
birds have by their first September learned that the song
should
be in three phrases and that the terminal phrase should contain a more
or less elaborate flourish'. Thus 'on the perceptory side the process
of recognizing and accepting the specific song as henceforth the
normal
for the individual (as distinct from the acquisition of
the new motor habits involved in performing the song) seems to resemble
the original examples of imprinting [the following response] sufficiently
close to warrant considering them together' (Thorpe, 1956, p. 375).

 

 

To
p. 491
. In the human child, processes analogous
to
Prägung
may perhaps be responsible for producing infantile
fixations and fetishistic rituals. The cases of boot-fetishism, for
instance, frequently reported in works on sexual pathology remind one of
imprinting by inanimate objects -- such as a gander's seven-year fixation
on an oildrum, reported by Thorpe (p. 365). A further analogy may be
found between Gestalt-sign releasers, based on the vital statistics of
film-stars, and Tinbergen's simplified laboratory models of the pregnant
stickleback.

 

 

To
p. 493
. Thorpe continues: 'However, the answer
may be that the nature of sensory nervous mechanisms is such that to
achieve full efficiency at the normal level of stimulation, the threshold
must be much lower.' (Thorpe, 1956, p. 283). But other passages which I
have quoted show that he does not regard this explanation as satisfactory.

 

 

 

 

 

VIII
MOTIVATION
Retrospect
Future historians will probably regard it as significant that throughout
the first half of the twentieth century the dominant schools of psychology
-- even schools as far apart as behaviourism and psychoanalysis --
recognized only one basic type of motivation, and that a negative one:
the reduction of biological needs and drives, the diminution of tension,
escape from anxiety. 'At the level of ego-psychology', wrote Mowrer
in his survey on 'Motivation' in the
Annual Review
for 1952,
[1] 'there may be said to be only one master motive: anxiety.'
The trend seems to have originated in the climate of the Darwinian
revolution independently in Germany and America, with Fechner's
(1873) 'Tendenz zur Stabilität' and Thorndike's (1898) 'Law of
Effect'. Freud (1920), acknowledging his indebtedness to Fechner,
postulated his own Principle of Parsimony, according to which 'the
course of mental events is invariably set in motion by an unpleasurable
tension, and it takes a direction such that its final outcome coincides
with a lowering of that tension'. Thus pleasure is derived from
'the diminution, lowering, or extinction of psychic excitation' and
'un-pleasure [
Unlust
, dysphoria, as distinct from physical pain]
from an increase of it'. The organism tends towards stability -- a kind
of homeostasis, applied not only to autonomic regulations but also to
voluntary behaviour; it is guided by 'the striving of the mental apparatus
to keep the quantity of excitations present in it as low as possible or
at least constant. Accordingly, everything that tends to increase the
quantity of excitation, must be regarded as adverse to this tendency,
that is to say, as unpleasurable'. [2]
Now this is of course true, in a broad sense, in so far as the frustration
or satisfaction of primary biological needs is concerned. But it passes
in silence a whole class of experiences to which we commonly refer as
'pleasurable excitement'. The preliminaries of love-making cause an
increase in sexual tension and should, according to the theory, be
unpleasant -- which they are decidedly not. It is curious that in the
works of Freud there is no answer to be found to this embarrassingly banal
objection. The sex-drive in the Freudian system is essentially something
to be disposed of -- through the proper channels or by sublimation;
pleasure is derived not from its pursuit, but from getting rid of
it. One might argue that in Freud's universe there is no place for
amorous love-play because Freud, like D. H. Lawrence, was basically a
puritan with a horror of frivolity, who treated sex
mit tierischem
Ernst
.* But arguments ad hominem do not explain the general trend
in the first half of the century to interpret motivation as something
negative. As Hilgard ruefully remarked, [3] the 'Zeitgeist favoured our
seeing incentives not as providing something sought after for what was
inherent in the incentive, but something providing relief. The incentive
was seen as an avenue of escape from pain, anxiety, tension.' Just as
Freud's libido-theory had no room for dalliance, so learning-theory had
no room for curiosity or learning-by-play.
Thorndike's 'Law of Effect' was essentially a stick-and-carrot theory;
the reward (and to a lesser degree, punishment) is the factor which
stamps in the correct responses in learning, and stamps out the incorrect
ones. In the extreme behaviourist systems of Watson and Guthrie, the
mechanization of the living organism is complete: contiguity is the basic
factor in producing associative S.-R. bonds, and motivation has virtually
disappeared from the picture. Nor is any theory of motivation allowed
to enter into Skinner's concept of 'operant behaviour'. His system is
by programme confined to the description of experimental operations,
preferably in quantitative terms. The effects of different rates and
sequences of positive and negative reinforcers are counted and plotted;
the entity on which they act is the 'operant strength', which in turn
is measured by the rate and number of responses during extinction; but
the motivation of the animal is represented by a single, crude variable:
the number of hours in which the rat had been deprived of food. Optimum
learning results from the combination of the appropriate number of hours
of deprivation with the appropriate rate of applying positive reinforcers,
i.e. stimuli of the type, one might say, which are apt to deprive the
organism of its deprivation. Differences between the learning abilities
of various species, or of age groups within a species, are not considered
to be relevant to this type of 'functional analysis' of behaviour. By
the same method of selective reinforcement, by 'baiting' each step in a
series of steps, pigeons can be trained to describe a figure-eight with
their heads held high, and students can be trained to select the right
answer among several alternatives and to punch it into the tape of the
learning machine -- the reinforcement in this case being that the tape
moves on to the next question. Since each reinforcer is a drive-reducer,
learning becomes a process of progressive de-motivation.
Hull did not share Skinner's rigidly positivistic,
hypotheses-non-fingo
attitude. He kept elaborating and
modifying his theory until his death in 1951; the system has been
described as the last and most impressive attempt to build an edifice
on S.-R. foundations. His emphasis gradually shifted from primary to
secondary drives and secondary rewards; and from need-reduction to
drive-stimulus reduction (eating eliminates the
stimulus
of
the hunger drive but not the biological
need
-- which will be
satisfied only later by digestion). This made the system more elastic,
yet in spite of these refinements, the primitive drives of hunger,
sex, avoidance of pain, were considered to be the only motivational
factors in learning. To quote Hebb's (1949) summing up of Hull's theory:
'Its weakest point, and clearest departure from the facts, is in the
treatment of motivation as biological need. According to the theory,
the rat in the maze should learn nothing about it until one of his
responses is accompanied by a decrease of hunger or thirst, or escape
from electric shock, or some similar reward. In actual fact, when he is
allowed to run in the maze without reward or punishment, the rat learns
a good deal about it. It is clear of course that the primitive drives of
pain, hunger, and sex are often of overwhelming importance. We need an
approach to motivation that neither minimizes these things nor fails to
provide for the unrewarded learning that also occurs when the animal's
belly is full and his sex drive satisfied.' [4]
If we turn to the opposite camp -- Tolman and the Gestalt psychologists --
the emphasis shifts from the need-reducing to the goal-seeking aspects of
behaviour. In classical Gestalt theory, motivation by rewards, usually
in the form of bananas, is taken for granted; it does not question
the effect of reward on learning, the dispute is about whether this
effect is achieved by stamping in or by insight. Similar considerations
apply to Tolman's sign-learning theory, although he has progressed a
considerable step further by his explicit rejection of reinforcement
theories, by his emphasis on 'expectancy' and 'purposiveness', on latent
learning and 'creative instability'. Lastly, Kurt Lewin's 'psychological
field theory', with its complex and changing motivation, its concepts
of 'ego-involvement' and 'levels of aspiration'; above all with its
notion of striving after 'success' (which is subjective and relative
in contrast to reinforcement by tangible rewards), played an important
part in promoting that change of climate which has been increasingly
noticeable since about 1950.
Decline of the Reflex
This new orientation seems to be the cumulative effect of independent
developments in several fields, such as: (a) disillusionment regarding
the utility of the reflex-formula both in neurology-and psychology;
(b) rediscovery of the fact that organisms are not passive masses
of software reacting to environment, but 'open systems', feeding on
'negative entropy', engaged in spontaneous activities on all levels,
and (c) that animals are capable of 'latent' learning in the absence of
tangible rewards, motivated solely by their exploratory drive.
(a) The
physiological
concept of the reflex arc, which even
Sherrington considered as no more than a 'useful fiction', has become an
anachronism.* The Pavlovian conditioned reflex was another useful fiction
which exercised at first a stimulating, then a paralysing effect -- a
phenomenon frequently met in the history of science. In Hebb's words:
'Pavlov has deservedly had a great influence on psychology, and his
theory has not been rejected because it is too physiological but because
it does not agree with experiment.' There is no need to recapitulate the
evidence which has led to this rejection. [5] 'Conditioning' is still
a useful term when applied to induced changes in glandular and visceral
reactions, but leads to confusion when used in a loose, analogical way
for other types of learning.
The last blow to the reflex-arc concept came with the discovery that
it was impossible to make a precise distinction between 'stimuli'
and 'responses'. As already mentioned (
p. 435
) not
only motor units, but also sensory receptors display constant spontaneous
activity in the absence of external stimulation. [6] External events
alter the pattern of this spontaneous activity, but this in itself
does not yet constitute a stimulus. The receptors are under efferent
control from higher levels of the central nervous system; the acceptance,
suppression, or modification of the input starts on the periphery, and the
centre decides what shall constitute a stimulus and what shall not. Even
the stretch-sensitive receptors in muscle spindles are controlled by
efferent fibres from the centre. In other words, 'stimuli' and 'responses'
are not one-way processes, and cannot be isolated: 'because stimulus and
response are correlative and contemporaneous, the stimulus processes must
be thought of not as preceding the response but rather as guiding it to a
successful elimination of the incongruity. That is to say, stimulus and
response must be considered as aspects of a feedback loop. . . . [7]
These properties are a far cry from the ubiquitous S.-R. reflex arc
diagrams that grace (more appropriately one wants to say "disgrace")
today's texts' (Pribram). [8]

 

 

It is historically interesting that an independent but parallel
softening-up process of the hard and fast S.-R. concept took place at the
same time in psychology, e.g. in Skinner's and Hull's systems. Skinner
was careful to state that he used the word 'reflex' not in an anatomical
or neurological sense but as a purely psychological, descriptive term for
the 'unit of behaviour'. But his definition of the unit was constantly
shifting and changing. 'A reflex is not, of course, a theory. It is a
fact. It is an analytical unit, which makes the investigation of behaviour
possible. [9] The appearance of smooth curves in dynamic processes
marks a unique point in the progressive restriction of a preparation,
and it is to this uniquely determined entity that the term "reflex"
may be assigned.' [10]

 

 

As Miller et al were to comment, to define the reflex in terms of the
smoothness of curves is a 'somewhat odd approach'. [11] Yet even
so it did not work: 'Skinner's "unit appropriate for experimental
study" turns out, in fact, to have a measure of arbitrariness about
it. . . . Sometimes the functional unit is a simple response, sometimes
a complex act, sometimes a rate of responding. The unit no longer has
the clean dimensions of a correlation between a class of stimuli and a
class of responses as implied in the original concept of a reflex. The
atom of behaviour proves to be evasive.' [12] In the later versions of
Skinner's system the stimulus no longer even precedes the response: in
operant behaviour the organism emits responses in search of a stimulus
as it were. The reflex as a unit of behaviour has evaporated like the
physicist's hard little lumps of matter.