Table Of ContentTHE BIOLOGY
AND EVOLUTION
OF LANGUAGE
Philip Lieberman
Language is the principal ornament of human
intellect—the badge our species traditionally
flashes to set itself off from the beasts. Yet
mutations large enough to account for human
language in a single step are extremely rare
and usually lethal. Must language be explained
by such an improbable evolutionary stroke?
Lieberman proposes a bold new approach to
this perennial puzzle—an approach that syn
thesizes much of the recent research which has
made the biology of language such an exciting
and fast-growing field. Drawing on data from
anatomy, neurophysiology, physiology, and
behavioral biology, he uses the synthetic theory
of evolution to develop a model of human lan
guage that differs profoundly from the philo
sophically based models typical of most
linguistic studies.
Lieberman argues that the biology of human
language is the result of many evolutionary
compromises. The discontinuity between the
organs of human language and the analogous
organs in related species is not as great as it has
been assumed. Small changes in the architec
ture of the vocal tract and in the matching per
ceptual mechanisms in the brain can lead to a
speaking species. Similarly, the control systems
in the brain employed in other species to
organize nonlinguistic activity may require
only minor adaptation to achieve human
syntax. There need be no master gene: the
language system might have assembled itself
out of structures originally engaged in other
functions.
The discussion ranges skillfully over matters as
various as the mating calls of bullfrogs, ape lan
guage, the size of elephant ears, computer-
implemented models of the brain, dyslexia,
and the theory of neoteny (which Lieberman
refutes). These excursions provide both an
introduction for the noninitiate and an occa
sion for expert debate.
THE BIOLOGY
AND EVOLUTION
OF LANGUAGE
THE BIOLOGY
AND EVOLUTION
OF LANGUAGE
Philip Lieberman
Harvard University Press
Cambridge, Massachusetts
London, England
1984
Copyright © 1984 by the President and Fellows of Harvard College
All rights reserved
Printed in the United States of America
10 9 8 7 6 5 4 3 2 1
This book is printed on acid-free paper, and its binding materials have
been chosen for strength and durability
Library of Congress Cataloging in Publication Data
Lieberman, Philip
The biology and evolution of language.
Bibliography: p.
Includes index.
1. Biolinguistics. 2. Language and languages — Origin.
3. Evolution. I. Title.
P132.L53 1984 401 83-22582
ISBN 0-674-07412-2 (alk. paper)
To
Erik and Diane Lund
and to
Arend Bouhuys (1925- 1979)
But we may go further, and affirm most truly that it is a
mere and miserable solitude to want true friends, without
which the world is but a wilderness. —Francis Bacon
PREFACE
Human language and cognitive ability are so linked to the question
of human uniqueness that we often implicitly accept the premise that
these abilities are unique. The thesis I shall develop is that our present
place in the scheme of things and the manifest differences between
human beings and all other living animals regarding language and
cognition follow from a sequence of small structural changes that
together yield a unique pattern of linguistic and cognitive behavior.
The total pattern of human behavior and human culture is unique,
but to understand how it evolved we must differentiate between the
biological “devices” that underlie human cognitive and linguistic
ability and these behavioral patterns. The distinction is similar to that
which we must draw between the electronic circuits and devices that
make up a digital computer and the computer’s programmed be
havior.
The evolution of human linguistic and cognitive ability, like
other aspects of human evolution, is probably the result of Darwinian
natural selection acting to retain structural variations that, though
they may seem small and trivial, made profound changes in human
behavior and culture possible. The anatomical development of the
opposable thumb, for example, facilitated the development of tool
culture. The development of the ability to produce sounds like the
vowel [i] (the vowel of the word bee) likewise facilitated the develop
ment of human speech, which in turn facilitated the rapid interchange
of information in humanlike animals who already had their hands
occupied using tools and carrying objects because of the previous
sequences of small anatomical changes that yielded upright bipedal
locomotion. The evolution of human linguistic and cognitive ability,
to me, thus is part of the general process of human evolution. The
data I discuss in connection with the evolution of human speech again
bear on the general question of the processes that were and are
operant in human evolution — these data refute the theory of neo-
teny.
The framework of this book is thus biological and differs from
that of most linguistic studies. A biological approach to the study of
language has as its goal the development of theories that can account
for the greatest range of data. A biological approach also takes into
account the genetic variation that is inherent in any human popula
tion. We should not expect to find a uniform “universal” grammar
vii
Vili Preface
that is based on identical biological mechanisms throughout the total
population. We again do not expect to find anatomical, physiologic,
or neural mechanisms that necessarily are “logically” designed. Bio
logical systems have an evolutionary logic that may, or may not,
conform to present-day notions of what constitutes an elegant or
simple solution to a problem. The human respiratory system, as we
shall see, looks like a Rube Goldberg system, but it works and has a
logic based on its particular evolutionary history. The transforma
tional, generative school of linguistics has resulted in a period of
intense linguistic speculation on what the properties of human lin
guistic and cognitive ability might be. The principal intellectual tools
of the linguists engaged in this endeavor have been their introspection
and some logical analysis. The range of acceptable data for linguistic
theories has, moreover, become ever more constrained and arbitrary
for many theoretical linguists continuing the trend established with
Saussure’s langue-parole distinction. The Chomskyian competence-
performance distinction imposes arbitrary limits on the range of
behavior and data that a linguistic theory should account for. We
simply do not know how we are put together. We do not know that the
biological mechanisms that structure linguistic ability also do not play
a role in structuring other aspects of human cognitive behavior.
Indeed, we are only beginning to understand how the brain may
function. We likewise have been able to identify only some of the
innate, genetically transmitted anatomical and neural mechanisms
that structure human speech and syntax. The path toward under
standing the nature of these mechanisms is to study them. My hope is
that this book will provide a useful starting point.
I would like to thank my friends and colleagues for their patience
in discussing, reading, and commenting on many aspects of this study.
I would especially like to thank Professors Sheila Blumstein, Henry
Kucera, Pauline Jacobson, Peter Eimas, James Anderson, Walter
Quevedo, Leon Cooper, and Robert Meskill of Brown University, as
well as Marcia Lieberman, Terrance Nearey, Robert Buhr, Karen
Landahl, Carol Chapin, and Jack Ryalls. John Mertus’s elegant com
puter programs made much of my research possible. Again I am
indebted to the many conversations I had with Franklin Cooper,
Alvin Liberman, and Katherine Harris at Haskins Laboratories; to
Eric Wanner at Harvard University Press; and to Jeffrey Laitman,
Edmund Crelin, and Alan and Beatrix Gardner. Moira Russo’s heroic
work with an obstinate word-processing system gave form to this
book, and the generous support of the National Institute of Child
Health and Human Development made possible research on the
development of speech in infants and young children.
CONTENTS
Introduction: The Biological Framework i
1. Neurophysiology, Neural Models, and Language 15
2. Distributed Neural Computers and Feature
Detectors 36
3. Automatization and Syntax 57
4. Syntax, Words, and Meaning 79
5. Respiration, Speech, and Meaning 98
6. Elephant Ears, Frogs, and Human Speech 123
7. Speech Is Special 138
8. Linguistic Distinctions and Auditory Processes 169
9. The Man on the Flying Trapeze: The Acquisition of
Speech 194
10. Apes and Children 226
11. The Evolution of Human Speech: Comparative
Studies 256
12. The Evolution of Human Speech: The Fossil
Record 287
Conclusion: On the Nature and Evolution of the
Biological Bases of Language 330
References 337
Notes 364
Index 371
