November 28, 1999Washington Sleeped
Past-tense verbs, Steven Pinker says, are a revealing
window on the workings of the brain.
By MARK ARONOFF
WORDS AND RULES
The Ingredients of Language.
Illustrated. 348 pp. New York:
teven Pinker first gained the attention of his academic peers with
two technical monographs on how young children acquire language. His
next book, a popular exposition of Chomskyan linguistic ideas, was a
runaway success with critics and with a larger audience and was
quickly followed by an almost equally successful general book on
psychology. Pinker is now an established public intellectual, the most
visible representative of the new field of cognitive science that has
grown up around computer science, linguistics and experimental
psychology. The publishers of his latest book, ''Words and Rules,''
fully aware of his status, have pulled out all the stops. On a recent
trip to Oxford, I found the book prominently displayed in the front
window of Blackwell's flagship bookshop as their book of the month.
The same day, I noticed a largish ad in The Times of London
advertising an appearance by Pinker to discuss the book, with
admission more than that of a first-run movie, sponsored by The Times
and another chain of booksellers, and moderated by The Times's science
editor. Pinker has become a media star throughout the English-speaking
A scholar who achieves global popularity has several paths open.
Pinker has taken advantage of his position to write a different kind
of book from any of his previous efforts: a popular exposition of the
line of technical scientific work he has been engaged in for the last
decade. He has thus chosen to follow in the footsteps of Stephen Jay
Gould, the most scientifically eminent of the current popularizers,
who similarly used his well-earned fame to write a book on the role of
fossils from the Burgess Shale beds in modern evolutionary theory, not
on the face of it a topic of wide public concern. Just as Gould
succeeded with the Burgess Shale, so has Pinker, but with an even less
likely topic: English past-tense verb forms.
The very notion that English past-tense verb forms could possibly
be the object of scientific inquiry will surely surprise most people.
Yet over the last two decades or so a growing number of linguists and
psychologists have successfully mined this unlikely seam for evidence
of how the mind works. The drama in Pinker's account of the research
is provided by three factors: there is a fundamental ideological split
between two schools of researchers studying the same data; Pinker's
school is decidedly in the minority; and the weapons wielded by both
sides have become increasingly sophisticated, so that the book becomes
a primer on neuropsychology, including new methods that allow us to
picture the inner workings of the human mind/brain.
Theories of how the mind/brain works have been dominated for
centuries by two opposing views. One, rationalism, sees the human mind
as coming into this world more or less fully formed -- preprogrammed,
in modern terms. The other, empiricism, sees the mind of the newborn
as largely unstructured, a blank slate. For the first half of this
century, while Freud ruled psychiatry and the nonacademic mind with
unverifiable speculation, scientific psychology was dominated by
behaviorism, a radical form of empiricism that countenanced only
minimal theoretical notions.
Then along came Chomsky. In 1959, in a long review in Language, the
leading journal of a field that was then obscure even by academic
standards, he eviscerated ''Verbal Behavior,'' the magnum opus of B.
F. Skinner, the dean of behaviorist psychologists and a popular
figure. He argued not only that behaviorist psychology failed to
explain language, but further (in a long series of technical and
semipopular works that continues to this day) that no theory could
account for the complexity and similarity of all human languages --
and the rapidity with which young children acquire them -- unless it
posited a complex pre-existing structure in the human mind/brain that
was purpose-built for acquiring language. Chomsky's arguments and
style were so powerful that his ideas overcame the obscurity of his
position to make him the leading thinker on the human mind of this
half of the century and to make rationalism scientifically
The simultaneous rise of computer science led to theories of
artificial intelligence and computer models of how the mind works,
often developed at the Massachusetts Institute of Technology, down the
hall from Chomsky in the legendary Building 20, a ramshackle wooden
structure built originally for the development of radar in World War
II. These models of intelligence shared with Chomsky's models of
language the use of systems of mathematical rules (symbolic systems)
to account for human thought. Behaviorism, which eschewed rules and
symbols in favor of simple association, appeared to be dead as a
theory of the human mind.
Or so it seemed until the mid-80's, when a school of
neobehaviorists rode out of the West (west of the Charles River, at
least), their computers loaded with memories as vast as that of
Borges's Funes the Memorious. They were driven by new discoveries
about the vast network of neurons in the brain, and they were armed
with mathematical tools called neural nets, which allowed them to
model the mind using no rules and no symbols, only association, just
like their behaviorist forebears. Like the Terminator, empiricism was
The associationists lost no time going after the rationalists,
taking direct aim at the heart of language: English verb forms. In
1986, the two leaders of this group showed how a network model of the
mind, using only association, could ''learn'' both regular English
past-tense verb forms, like ''looked,'' and irregular verb forms, like
''saw,'' simply by being exposed to the past forms and their
corresponding simple forms (''look'' and ''see'') a very large number
of times. Even better, this model would produce the same sorts of
errors children produce, such as ''sawn,'' ''sawed'' and ''seed,''
without rules or symbols. This assault on the symbolists was not,
however, quite as decisive as Chomsky's one-man commando raid, and the
two sides have been fighting it out ever since in academic journals
and the halls of the major funding agencies.
Pinker has been a major player on the symbolist side, but with a
twist. His position is that every language contains both a system of
rules and an associationist network, and that this bifurcation is most
readily revealed -- you guessed it -- in the past-tense forms of
English verbs. According to this view, the regular past-tense verbs,
like ''looked'' or ''prevaricated,'' are produced by rule when needed,
just as sentences are. The irregular verbs -- won'' and ''went'' and
about 200 others in modern English -- are memorized, just the same as
simple words like ''dog'' or ''mind,'' and constitute an
associationist network. Pinker calls his the words-and-rules theory;
thus the title of the book. If he is correct, he notes, it may be that
the rule system and the associationist net actually reside in
different parts of the brain, and furthermore we may be able to
pinpoint these two parts of the brain precisely. The second half of
the book is devoted to showing just that.
Pinker's evidence embraces many lines of scientific inquiry, from
the armchair analysis of exotic languages by academic linguists to
science-fiction brain mapping techniques like functional magnetic
resonance imaging and positron emission tomography. Along the way, we
visit Alzheimer's and Parkinson's diseases, one of which seems to
cause people to lose their regular verbs, the other their irregular
verbs (presumably because the diseases affect different parts of the
brain); we meet people with genetic defects that hamper their ability
to produce past-tense verbs (possibly including Jean Chretien, the
prime minister of Canada); and we find out why, although it is
perfectly normal for a batter to fly out to left field, no batter has
ever flown out there -- they've all flied out.
Pinker's intellectual opponents may feel he is overgenerous to his
own side. For example, while it is true that several positron emission
tomography studies have claimed to show that regular and irregular
forms reside in different parts of the brain, as Pinker says they
should, no two have agreed on where those parts are. But no one can
expect a popular work to discuss all the evidence. Over all, Pinker is
quite balanced in his presentation.
For a couple of years, I have contemplated writing a book like
this, but I kept bringing myself back to reality with the thought that
no one would read such a book, no matter how good, unless Steven
Pinker wrote it. Now he has written it, and it is a gem.
Mark Aronoff, the editor of the journal Language, is a professor of
linguistics at the State University of New York, Stony Brook. He is
the editor, with Janie Rees-Miller, of the Blackwell Handbook of
Linguistics, to be published next year.