unit
of behaviour?
I seem to be labouring points which are obvious to the non-psychologist,
but the purpose will soon become apparent. Obviously, then, the phrase
'Don't mention it' might also produce the response 'Well, goodbye' or
'You have got a ladder in your stocking' or a number of alternative
'bits of verbal behaviour', according to whether She uttered the phrase
lingeringly with a sexy smile, or as a brisk brush-off, or hovering
between the two; and further depending on whether or not He finds her
attractive, whether He is free for lunch, and if so whether He has the
cash to pay for it. The simple S-R unit is neither simple nor a unit. It
is difficult for the layman to believe that the textbook author is not
aware of the complex, multi-levelled mental processes which go on in the
two people's heads during and in between the emission of sounds. Surely
these 'private processes' must be implied, taken for granted, in what the
author is saying? Perhaps they are; but by denying that private events
have a place in psychology, he has denied himself the possibility,
and even the vocabulary to discuss them. The Behaviourist's way to
get around this difficulty is to lump all these unmentionable private
processes together in the nondescript term 'intervening variables'
(or 'hypothetical mechanisms') which 'mediate between stimulus and
response'.* These terms are then used as a kind of garbage bin for the
disposal of all embarrassing questions about the intentions, desires,
thoughts and dreams of the organisms called He and She. An occasional
reference to 'intervening variables' serves as a face-saving device, since
everything that goes on in a person's mind is covered by it, and need not
be discussed. Yet in the absence of any discussion of the mental events
behind the dialogue, the comments of our textbook author are reduced to
utter triviality, and the neat diagram is empty of meaning. A diagram is
meant to give a graphic representation of essential aspects of a process;
in this case both text and diagram pretend to do so, but in fact give
no indication of what is really happening. The same dialogue could have
taken place between casual acquaintances, or shy lovers, or it could
record the picking up of a prostitute. The pseudoscientific balderdash:
'When He emits the operant, "What time is it?", the muscular activity
produces a sound which also serves as a stimulus,' and so on, is totally
irrelevant to the episode it pretends to describe and explain. And this
applies generally to any attempt to describe the language of man in
terms of S-R theory.
* See Appendix Two.
The Tree
The strategic advantage gained from labouring the obvious absurdity of
a theory is that it makes the proposed alternative appear as almost
self-evident. The alternative, set out in the pages that follow,
proposes to replace the concept of the linear S-R chain by the concept of
multi-levelled, hierarchically ordered systems, which can be conveniently
represented in the form of an inverted tree, branching downward:
We find such tree diagrams of hierarchic organisation applied to the
most varied fields: genealogical tables; the classification of animals
and plants; the evolutionist's 'tree of life'; charts indicating the
branching structures of government departments or industrial enterprises;
physiological charts of the nervous system, and of the circulation
of the blood. The word 'hierarchy' is of ecclesiastical origin and is
often wrongly used to refer merely to order of rank -- the rungs on a
ladder, so to speak. I shall use it to refer not to a ladder but to the
tree-like structure of a system, branching into subsystems, and so on,
as indicated in the diagram. The concept of hierarchic order plays a
central part in this book; and the most convenient way to introduce it
is by means of the hierarchic organisation of language.
The young science of psycholinguistics has shown that the analysis of
speech presents problems of which the speaker is blissfully unaware.
One of the main problems arises from the deceptively simple fact that
we write from left to right, producing a single string of letters, and
that we speak by uttering one sound after the other, also in a single
string, along the axis of time. This is what lends the Behaviourist's
concept of a linear chain its superficial plausibility. The eye takes
in a whole three-dimensional picture, embracing many shapes and colours
simultaneously; but the ear only receives linear pulses one at a time,
serially, and this fact may lead one to the fallacious conclusion that
we also
respond
to each speech-sound, bit by bit, one at a time.
This is the bait which the S-R theorist has swallowed, and on which he
has been dangling ever since.
The elementary speech souncls are called phonemes; they correspond roughly
to the written alphabet; in English there are forty-flve of them. If
listening to speech consisted in the chaining of separately perceived
phonemes by the listener, he would literally not understand a word of
what is said to him. Let me explain this paradox. If we were to translate
the process of listening to speech from acoustical into optical terms,
this would mean flashing onto a screen before the subject's eye printed
letters one by one, at the rate of twenty letters per second. The result
would be something like a nervous breakdown. The ear of the listener
has to take in about twenty phonemes per second. If he tried to analyse
each phoneme as a separate 'bit' -- or atom, or segment of language --
all he would perceive would be a steady buzz. I owe this illustration to
Alvin Liberman of the Haskins Laboratories -- a pioneer in the field of
speech-perception, and a participant in the Think-Tank seminar mentioned
in the preface. He also commented wryly that if we go on labouring the
point with the methods of the S-R theorist, 'we risk arriving at the
conviction that human speech is an impossibility'.
The solution of the paradox becomes apparent when we revert from spoken
to written language. When we read, we do not perceive the shape of one
letter at a time (as in the screen-experiment just mentioned), but the
patterns of one or several words at a time; the individual letters are
perceived integrated into larger units. Similarly, when listening, we
do not perceive separate phonemes in a serial order; perception combines
them into higher units of approximately syllabic size. The speech sounds
unite into patterns as musical sounds unite into melodies. But unlike
the three-dimensional patterns perceived by the eye, speech and music
form patterns in the single dimension of time -- which seems mysterious
and baffling. We shall see, however, that the recognition of patterns
in time is no more -- and no less -- baffling than the recognition of
patterns in space, because the brain constantly transforms temporal
sequences into spatial patterns and vice versa (page 81). If you look at
a gramophone record through a magnifying glass, you only see a single,
wavy spiral curve, which, however, contains in coded form the infinitely
complex patterns produced by an orchestra of fifty instruments performing
a symphony.
The airwaves which it sets in motion form, like the curve on the groove,
a sequence with a single variable function -- the variation of pressure
on the eardrum. But a single variable in time is sufficient to convey the
most complex messages -- the Ninth Symphony or the Ancient Mariner --
provided there is a human brain to decode it, to retrieve the patterns
hidden in the linear sequences of pressure waves. This is done by a
series of operations, the nature of which is as yet little understood, but
which can be represented as a multi-levelled hierarchy of processes. It
has three main sub-divisions: the phonological, syntactic and semantic.
'What Did You Say?'
We may regard as the first step in decoding the spoken message -- the
first step up the hierarchic tree -- the integration by the listener
of phonemes into morphemes. Phonemes are just sounds; morphemes are the
simplest meaningful units of language (short words, prefixes, suffixes,
etc.); they form the next higher level of the hierarchy. Phonemes do
not qualify as elementary units of language, first because they come in
much too fast to be individually discriminated and recognised, but also
for a second important reason: they are ambiguous. One and the same
consonant sounds different, depending on the vowel which follows it,
and vice versa, different consonants sometimes sound the same in front
of the same vowel. Whether you hear 'big' or 'pig', 'map' or 'nap',
depends, as the Haskins Laboratory experiments show [4], largely on the
context
. Thus the S-R chain theory breaks down even on the lowest level
of speech, because the phonemic stimuli vary with the context, and can
only be identified in the context. But as we move upward to higher levels
of the hierarchy we again meet the same phenomenon: the 'response' to a
syllable (its interpretation) depends on the word in which it occurs;
and individual words occupy the same subordinate position relative to
the sentence as phonemes relative to words. Their interpretation depends
on the context, and must be referred to the next higher level in the
hierarchy.
The late K. S. Lashley -- a Behaviourist turned renegade --
has given an amusing illustration of this:
Words stand in relation to the sentence as letters do to the word;
the words themselves have no intrinsic temporal 'valence'. The word
'right', for example, is noun, adjective, adverb, and verb, and
has four spellings and at least ten meanings. In such a sentence as
'the mill-wright on my right thinks it right that some conventional
rite should symbolise the right of every man to write as he pleases',
word arrangement is obviously not due to any direct associations of
the word 'right' itself with other words, but to meanings which are
determined by some broader relations. . . . Any theory of grammatical
form which ascribes it to direct associative linkage of the words
of the sentence overlooks the essential structure of speech. [5]
This is of course an extreme example of contrived ambiguity, but it
makes its point with a vengeance against the S-R theorist who contends
that speech sounds are 'like other bits of behaviour', and that language
calls for no principles of explanation other than those employed in the
operant conditioning of lower animals.
The ideal situation from the S-R theorist's point of view is a
typist -- let's call her Miss Resp -- taking dictation from her boss,
Mr. Stims. Here, one would think, we have a perfect example for a linear
chain of sound stimuli controlling a string of key-pressing responses
(Miss Resp being reinforced by Stims with the prospect of a salary). Since
complex behaviour is supposedly the result of the chaining of simple
S-R links, we must assume that each sound emitted by Stims will cause
Miss Resp to type the corresponding letter (provided he dictates at the
same speed at which she types, which is assumed). But we know of course
that something quite different happens. Miss Resp waits expectantly,
doing nothing, until at least half the sentence is completed, then,
like a sprinter at the starter's shot, races ahead until she has caught
up with Stims; then waits expectantly with an admiring expression on her
face. The phenomenon is known to experimental psychologists as 'lagging
behind'; it also occurs in Morse telegraphy and has been studied in
great detail.* Miss Resp was lagging behind because she was mentally
engaged in climbing the tree of language: first up, from sound level to
word level to phrase level, then down again. The downward climb in the
case of a skilled typist leads from 'phrase habit' through 'word habit'
to 'letter habit'. The letter habits (hitting the correct key) are part
of the word habits (a pre-set patterned sequence of movements triggered
off as a single unit), which are part of the phrase habit (familiar
turns of phrase which activate 'sweeps' of movements as integrated
wholes). Although the performance is to a large extent as 'automatic'
or 'mechanical' as any Behaviourist could wish for, it is nevertheless
impossible to represent it as a linear chain of conditioned responses,
because it is a multidimensional operation constantly oscillating between
various levels, from the phonological to the semantic. No typist can be
conditioned to take dictation in a language she does not know. It is this
very complex knowledge, and not the chaining of simple S-R connections,
which makes Miss Resp's fingers dance on the keyboard to Mr. Stim's
reinforcing voice. And, oh wonder, she can even type a letter
withou
t
dictation, for instance to her fiancé in Birmingham. In this case her
behaviour is presumably controlled by S-R links which, like gravity,
are capable of action-at-a-distance.