Place/Catania: THE ROLE OF THE HAND IN THE EVOLUTION OF LANGUAGE
Retrieve the full text at:
http://www.cogsci.soton.ac.uk/cgi/psyc/newpsy?11.007
ftp://ftp.princeton.edu/pub/harnad/Psycoloquy/2000.volume.11/
psyc.00.11.007.language-gesture.1.place
--------------------------------------------------------------------
30. It is proposed that in previous linguistic training the behaviour
of picking (nota bene) the drawing of a car (the target in the case of
the upper figure), when presented with the written word CAR as sample,
and the behaviour of picking the written word CAR (the target in the
case of the lower figure), when presented with the drawing of a car as
sample, have both been reinforced. As a consequence these two stimuli
are treated as equivalent and are said to have become members of the
same stimulus equivalence class. Although in this particular example
the equivalence class has been formed by linguistic training outside
the laboratory, there is a wealth of experimental evidence showing that
in human children and adults any two arbitrarily selected stimuli can
be formed into an equivalence class by this procedure. Despite the
fact that the experimental technology tends to restrict research to the
investigation of arbitrary associative links between static visual
shapes (but see Sidman [1990] Figure 4.2, p.95, for an experiment in
which the sample is spoken word), it is generally agreed by workers in
this field that the ability to form stimulus equivalence classes in
this sense is intimately associated with the early stages of language
development in the human infant.
31. According to the view endorsed here (Place 1995/6), an arbitrary
response-produced stimulus becomes a symbol for or name of some
individual object or kind of object, property, relation or event when,
as illustrated in the schematic, it becomes a member of a stimulus
equivalence class which includes amongst its members one or more
natural signs of the presence of the individual or kind which it
thereby symbolises. The propensity of the child that is developing
language to form such stimulus equivalence classes is seen as a result
of having repeatedly learned both, as speaker, to produce the symbol or
name in the presence of a natural sign of the thing it `stands for'
and, as listener, to pick out the natural sign when presented with the
symbol or name.
32. Despite many attempts to do so, there is no convincing evidence that
any animal species, including apes who have been taught to use
sign-language or other symbols, has spontaneously developed a stimulus
equivalence class in the way human children invariably do, i.e., unless
the individual has been specifically trained to respond to each of the
possible combinations of sample and comparison. There is evidence,
moreover (Beasty 1987; Dugdale & Lowe 1990; Horne & Lowe 1996), which
links the emergence of spontaneous stimulus equivalence class formation
with the use of names to distinguish the stimuli the child is learning
to associate. Animals who have been taught to use symbols not only fail
to show the spontaneous formation of stimulus equivalence classes. They
also fail to show the exponential increase in vocabulary size which has
been referred to as the naming explosion and which would seem to begin
in the child at about the same time (around the age of two). It seems
that a mutation has been selected which gives human beings the ability
to form the kind of associations involved in giving significance to
arbitrary symbols far more readily than any other species.
II.xiii. BICKERTON'S PROTO-LANGUAGE
33. Because the work that has been done on the formation of stimulus
equivalence classes has focused on static visual stimuli, it is
directly relevant only to the acquisition of object-names. How
action-names are acquired has not been studied from this perspective.
However, it seems likely that this ability grew out of the ancient
practice of representing actions by mimed movement, just as the ability
to acquire object-names appears to have grown out of the practice of
pointing at objects in order to establish reference to them. Once
object-names and action-names have been acquired it becomes possible to
construct sentences in what Bickerton (1990) has called proto-language
in which sentences consist of an object-name or noun specifying the
agent, an action-name or verb specifying the action to be performed,
and a second object-name or noun specifying the manipulandum. Horne and
Lowe's (1996) 'Daddy push car' is a typical example of just such a
sentence. Apart from the distinction between verb and noun and the
order in which the different components of the argument structure
occur, such sentences are devoid of syntax. Nevertheless, within their
limitations, they provide the rudiments of a working symbolic
language.
II.xiv. THE PRINCIPLE OF THE PROGRESSIVE EXTENSION OF REFERENTIAL SCOPE
34. As language develops in the child and as it presumably developed in
the species, reference is initially restricted to objects in the
current common stimulus environment of sign-producer and sign-receiver
to which the sign producer refers by pointing at them. With the
introduction of iconic representation reference is extended to objects
which are absent from the common stimulus environment of both speaker
and listener, but only in so far as either their shape can be depicted
by means of a mimed movement or their sound can be vocally imitated.
With the introduction of symbolic representation reference is extended
to absent objects, both individuals and kinds, to which a name has been
assigned by the conventions of the language. With the introduction of
syntax, particularly with the introduction of embedded clauses, it
becomes possible to refer to absent objects by description.
III. EVIDENCE FOR THE ROLE OF THE HUMAN HAND IN THE EVOLUTION OF
LANGUAGE
35. Before proceeding to detailed reconstruction of the evolution of
language based on these principles, it will be helpful to review some
of the evidence which supports the view that the freeing of the human
forelimb from its locomotor functions, and the consequent development
of manipulative skills, is as important for the evolution of language
as it clearly is for the evolution of technology. The following pieces
of evidence are relevant in this connection:
III.i. A GOOD VOCAL APPARATUS IS NOT ENOUGH
36. Many birds have a vocal apparatus as good as that of humans; yet
they have not developed language. This suggests that the crucial
difference between birds and humans in this respect may be that, while
both are bipedal, the forelimbs of birds are still specialised for
locomotion, rather than, as in the human case, for manipulation.
III.ii. GESTICULATION AS THE INVARIABLE ACCOMPANIMENT OF SPEECH
37. The occurrence of gesticulation as an invariable accompaniment of
speech strongly suggests that gesticulation had a much more important
role in the early stages of language evolution.
III.iii. GESTICULATION AS THE INVARIABLE DEFAULT WHEN SPEECH IS BLOCKED
38. Whenever vocal communication is blocked, either because it cannot
be heard or, if heard, cannot be understood, human beings of every
culture invariably fall back on gesticulation.
III.iv. SIGN-LANGUAGE
39. The ease with which the deaf learn sign-language, particularly if
brought up in an environment in which signing is in constant use by
others, and the spontaneous development of homesigning by those who are
not, suggests that the ability to use and respond to manual signs is an
integral part of our human linguistic heritage.
III.v. REFERRING TO AN OBJECT BY POINTING AT IT
40. The practice of pointing with the index finger as a way of
establishing reference to objects in the common stimulus environment of
speaker and listener is a linguistic universal which by common consent
plays an essential role in the acquisition of word-meanings.
III.vi. SENTENCES IN THE LANGUAGE OF GESTURE
41. The earliest form of sentence seems to have been one in which the
function (action) is indicated by means of a mimed movement and the
arguments by pointing at the objects concerned. Communication which
relies exclusively on sentences of this type constitutes a language of
gesture (Piaget 1926/1932; Hewes 1973a; 1973b; 1976) on which human
beings invariably fall back when vocal communication is blocked.
III.vii. THE ASSOCIATION BETWEEN HANDEDNESS AND LANGUAGE IN
BRAIN-LATERALISATI0N
42. The concentration of areas specialised for language in the same
hemisphere of the cerebral cortex as that which controls the hand which
is preferred for precise manipulative tasks demonstrates the intimate
connection between the two functions (Cf. Hewes 1973b, p.9).
III.viii. READING ABILITY CANNOT HAVE EVOLVED TO DECIPHER WRITING
43. There is a part of the human cerebral cortex, the angular gyrus on
the dominant (usually left) hemisphere, which is specialised for
deciphering linguistic stimuli in the visual modality (Thompson 1993,
pp.399-402). Since writing and reading have developed far too recently
and are still far from universal human accomplishments, the need to
decipher a written text cannot explain the development of this ability
to process visually presented linguistic signs. It must have been
selected, probably before the development of speech, to facilitate the
interpretation of a language of gesture.
III.ix. RIZZOLATTI AND ARBIB'S LANGUAGE IN OUR GRASP
44. In a recent paper entitled 'Language in our grasp', Rizzolatti and
Arbib (1998) have reached a similar conclusion in the light of evidence
that Broca's area in the human left frontal cortex, long known as the
area involved in the production and interpretation of syntactically
articulated sentences, is homologous with an area in the monkey's brain
(F5) where neurons (mirror neurons) have been found which respond both
to the production of visually-controlled hand-movements and to the
visual perception of the corresponding movements when made by others.
Although Rizzolatti and Arbib do not make these points, it is evident
that this link between the execution of a voluntary hand-movement and
the visual perception of similar movements made by others is (a) a
by-product of the visual feedback-control of voluntary movement, (b)
the foundation for the ability to imitate the hand-movements of others
without which a human technology based on the manufacture and use of
tools would have been impossible, and (c) the foundation of the ability
found, as we have seen, in chimpanzees to communicate by miming the
action to be performed by the sign-receiver.
III.x. COUNTING AND THE COMMUNICATION OF NUMBER USING THE FINGERS OF
TWO HANDS
45. No one would seriously dispute the claim that the earliest form of
counting consisted in the practice which is found in every human
culture of counting up to ten on the fingers of the two hands, and
displaying the result to others by holding up the relevant number of
fingers. This practice can, perhaps, be seen as an outgrowth of the
ability to refer to objects by pointing at them. But since what is
pointed at are the fingers rather than the objects being counted, this
form of counting is an iconic representation of the number of the
objects. Furthermore since you can only count things of a kind,
counting presupposes a pre-existing ability to classify objects into
kinds and, in the case of communicating the results of a count, a
pre-existing ability to indicate the kind of object being counted. (I
am indebted to Professor Robbins Burling of the University of Michigan
[personal communication April 1998] for convincing me that, unlike
vocal counting which is inevitably symbolic from the outset, digital
counting, together with some written number systems such as the Roman
before the practice of writing IV instead of IIII was introduced, is a
form of iconic rather than, as I had previously thought, a form of
symbolic representation.)
III.xi. POINTING AND PICKING IN THE LEARNING OF OBJECT-NAMES
46. The recent work on the process whereby arbitrary response-produced
stimuli become symbols for (names of) objects, described in section
II.XI above, argues for a key role in this process for the manual
responses of pointing at and picking out the relevant stimuli.
III.xii. THE ROLE OF MIMED ACTION IN THE LEARNING OF ACTION-NAMES
47. Little appears to be known about the process whereby action-names
are learned. What is known (Khler 1921/1927) is that chimpanzees
communicate what they want a conspecific to do by miming the action in
question, and such miming is a conspicuous feature both of the
gesticulation that invariably accompanies speech, unless the hands are
otherwise engaged and of sign-languages, whether officially recognised
or devised by the individual. This suggests that miming of the action
by the caregiver and its imitation by the child must play a key role in
the acquisition of action-names.
IV. A HYPOTHETICAL SCENARIO FOR THE EVOLUTION OF LANGUAGE
48. In the light of this evidence and the principles outlined in
sections I and II above, I would propose the following scenario for the
evolution of what I am suggesting is the sequence of stages involved in
the evolution of language:
IV.i. MIMED ACTION
49. The first stage in the evolution of language appears to have
occurred at a time when chimpanzees and humans had a common ancestor.
Three interconnected abilities would seem to have developed at this
stage: (a) the ability to use sticks and stones as tools and weapons,
(b) the ability to imitate the movements of others in the context of
learning to perform the manipulations involved in the effective use of
tools and weapons, and (c) the ability to communicate what one wants
someone else to do by miming the action required. There is some reason
to think that the concentration of the manipulative and communicatory
functions in one hemisphere of the cerebral cortex (the left in those
who are right-handed) may have begun at this stage, perhaps with the
specialisation of such structures as the angular gyrus and the
pre-motor cortex in the dominant hemisphere for the visual
interpretation of hand-movements in general and gesture in particular.
IV.ii. THE LANGUAGE OF GESTURE
50. The second stage culminates in the emergence of the first true
sentences formulated in the language of gesture. It begins with the
emergence of the practice of pointing referentially at objects, at the
individual who is to do something, at an object to be manipulated, at a
destination or location to which the individual is to move or to which
the object is to be moved. As we have seen (Section II.IV above), this
ability is lacking in chimpanzees, not because it is something they
cannot learn to do, but because referential pointing is something to
which, unlike dolphins, they cannot learn to respond. We have also seen
reason to agree with Noble and Davidson's (1996) suggestion that this
ability may have evolved with the development of the ability of a group
of hunters to aim their weapons at the same target. Given the ability
to use pointing to distinguish (a) who is to perform the action, (b)
the object to be manipulated and (c) the individual to whom the object
is to be transferred, it becomes possible for the first time in the
history of communication between living organisms to construct novel
sentences in what may be justly described as the language of gesture in
which different mimed actions are combined with different combinations
of argument (agent, object and recipient) identified by pointing at
them.
51. (Dr. Marina Sbis of the Department of Philosophy, University of Trieste
[personal communication, June 1998], has drawn my attention to the fact
that human infants frequently indicate the object to be manipulated by
an adult, in the case of a small portable object such as a bowl, by
bringing it to the adult or, in the case of a larger object by dragging
the adult towards it. It is not clear to me whether this behaviour is
part of the miming of the action to be performed which is already
present in the behaviour of chimpanzees or whether it is a separate
development, possibly connected to the technology of using containers
to collect, store and distribute liquids such as water and milk and
solids such as fruit and grain.)
52. But significant though it is, the practice of referring to objects by
pointing at them is severely limited in its scope. Whereas mimed action
allows the communicator to refer to what has not yet occurred, the
action to be performed by the respondent, referring to objects by
pointing at them allows the communicator to refer only to conspicuous
objects in the stimulus environment of both parties. The effect of
subsequent developments is to increase that scope beyond what is
indexically present.
IV.iii. ICONIC VOCALISATION
53. In Stage 3 vocalisation is added to the language of gesture. It
depends on changes to the conformation of the mouth and larynx which
are selected in the first instance by their effect in allowing human
beings to imitate the sounds made, for example, by the male or female
of the species to attract a potential mate, thereby enticing the latter
into the traps which the technology provides. Once established such
calls are introduced into otherwise gestural sentences as an
alternative to pointing at instances of the object where no such
instance is present. Since there is no obvious trace of the kind of
iconic gestures used by homesigners to represent objects (Morford et
al. 1993) in the gesticulations of those without auditory impairment, I
am inclined to think that the vocal imitation of sounds made by animals
were the first iconic representations of objects, as distinct from the
iconic representations of actions by means of mimed actions which have
been used since the days of our ape ancestors to represent the action
to be performed by the sign- recipient. They make it possible for the
first time to talk about absent objects as well as actions not yet
performed.
IV.iv. COUNTING
54. The position of this fourth stage in the sequence of evolutionary
events leading to fully developed language is unclear. It is placed
here because it can be plausibly seen as the first step in the move
away from the iconic towards a symbolic system of representation. It is
the development of the ability to count up to ten on the fingers of the
two hands and communicate the result by holding up the appropriate
number of fingers. Considered as a representation of the number of
objects in a group, holding up the corresponding number of fingers may
be considered iconic. But, once they progress beyond the number of
fingers on the two hands, counting systems inevitably become symbolic.
Vocal counting is invariably symbolic from the outset.
IV.v. SYMBOLS
55. In Stage 5 the first representations of objects using arbitrary
symbols (names) begin to appear. Once the use of symbols is well
established in the repertoire of a human child, all that is required
for the child to learn a new name or other lexical word is for the
instructor to point to one or two instances of the kind of object the
word is used to refer to while uttering the word in question. However,
the evidence reviewed in Section II.XI above suggests that in its early
stages learning the names of things is a much more complex process, one
in which there is reinforcement both of the response of producing the
name in the presence of an instance of the kind in question and the
response of picking an instance of the kind in the presence of the
name. Although apes, and possibly members of other animal species, can
be taught to use symbols, they never progress to the point where there
is spontaneous generalisation in both directions between the word or
symbol and the natural signs of the presence of the object for which it
stands. To be able to learn word-meanings as easily as a human child
does from about the age of two requires a mutation which has occurred
and been selected only in the human species.
56. Apes who have been taught sign language or some other form of symbolic
communication can construct sentences in what Bickerton (1990) calls
proto-language. But without the rapidly expanding vocabulary that seems
to develop only with the spontaneous emergence of stimulus equivalence
classes, language can never take off as it does in the human child.
Even so, consisting as they do entirely of names (lexical words),
proto-language sentences have no syntax other than the verb/noun
distinction. That, and perhaps some of the other distinctions that are
later drawn by means of syntax, are indicated by gesture which, at this
stage, still forms an integral part of the process of linguistic
communication. This is the first stage in the evolution of language
where the increased efficiency of language as a medium for
interpersonal and intrapersonal communication is unquestionably what
determines the selection of the mutation that provides it, rather than
its utility in relation to some purely technological adaptation. It is
at this stage presumably that Wernicke's area evolves as a centre for
the interpretation and production of names. With the development of
symbols (proper names) referring to particular persons and places,
unambiguous reference to individuals in their absence becomes possible
for the first time.
IV.vi. QUESTION AND ANSWER
57. As argued in Section II.III above, the developmental evidence
suggests that the first sentences produced and responded to by our
ancestors in the course of language evolution were all imperatives. It
also seems likely that the earliest declarative sentences were answers
to questions and that questions and answers evolved simultaneously as
part of a single practice. As in the case of counting, it is unclear at
what stage in the evolution of language this development took place.
The best guess is that it was associated, as it seems to be in
children, with the so-called naming explosion which occurs around the
age of two or three and consists in a rapid increase in the child's
vocabulary, particularly the names of kinds of object. This event
appears to coincide with the child's discovery of the practice of
asking questions of the caregiver, particularly questions about the
names of things, a practice which, like the naming explosion it
triggers, seems to be absent from the behaviour of the most intelligent
of those apes who have been taught a form of sign-language.
IV.vii. SYNTAX
58. The development of syntax is the final stage in the evolution of
language. It is selected by virtue of its effect in releasing
linguistic communication from dependence on the listener's paying
attention to the context of utterance and the gestures of the speaker
in order to disambiguate what a speaker is saying. It thus allows
speakers to talk intelligibly about situations which are not part of
the current stimulus environment of either speaker or listener, whether
in the past, in the future or at some place geographically remote from
the context of utterance. Once it is fully developed, gesture, though
still a valuable aid to the speaker's eloquence, ceases to perform any
essential communicatory function as far as the listener is concerned.
But, if gesture itself has been made redundant for all but the deaf by
the introduction of syntax, it seems that the connection between
language and manual and other forms of motor skill still survives in
the remarkable parallel to which Horgan and Tienson (1996) have drawn
attention between the syntactic organisation of sentences and the
syntactic (no metaphor) organisation of a motor skill such as
basket-ball playing.
59. It is an open question whether syntax evolved, as Chomsky would have us
believe, through a single mutation, or whether the emergence of each
class of syntactic operator required the selection of a separate
mutation. In favour of the former view is the existence of a single
area in the human cerebral cortex, Broca's area, which is specialised
for its interpretation and production, damage to which appears to
affect all types of syntactic operator more or less equally (Thompson
1993, p.398). In favour of the latter view is the observation that the
order in which the different classes of syntactic operator are acquired
by the child is a linguistic universal (Slobin 1985; Aitchison 1989).
With the introduction of syntax, particularly the definite article and
the relative clause, it becomes possible for the first time to refer to
absent objects by description as well as by proper name.
ACKNOWLEDGMENTS
I am indebted for their stimulating comments and for additional
references to Bernard Bichakjian, Paul Bloom, Rob Burling, Annabel
Cormack, Tom Dickins, Heng-syung Jeng, Harry Jerison and Jill Morford.
Since I have not otherwise cited his work, I should also express my
indebtedness to Lev Vygotsky's (1934/1986) Thought and Language to
which, among other things, I am indebted for the crucial references to
Koehler, Piaget and Wundt.
REFERENCES
Aitchison, J. (1989) The Articulate Mammal: An Introduction to
Psycholinguistics, Routledge.
Barwise, J. & Perry, J. (1983) Situations and Attitudes, MIT Press.
Beasty, A. (1987) The role of language in the emergence of equivalence
relations: A developmental study. Unpublished Ph.D. thesis, University
of Wales, Bangor, U.K.
Bickerton, D. (1990) Language and Species. University of Chicago
Press.
Chomsky, N. (1957) Syntactic Structures. Mouton.
Chomsky, N. (1965) Aspects of the Theory of Syntax. MIT Press.
Condillac, B. de (1746/1947) Essai sur l'origine des connaissances
humaines, ouvrage ou l'on rduit un seul principe tout ce concerne
l'entendement. In: Oeuvres Philosophiques de Condillac. Paris: Georges
LeRoy.
Dugdale, N. & Lowe, C.F. (1990) Naming and stimulus equivalence. In:
Behaviour Analysis In Theory and Practice: Contributions and
Controversies, ed. D. E. Blackman & H. Lejeune. Erlbaum.
Fodor, J. (1975) The Language of Thought. MIT Press.
Frishberg, N. (1975) Arbitrariness and iconicity: Historical change in
American Sign Language. Language 51:696-719.
Greenfield, P. M., & Savage-Rumbaugh, E. S. (1990). Grammatical
combinations in pan paniscus: processes of learning and invention in
the evolution and development of language. In: Language and
Intelligence in Monkeys and Apes: Comparative Developmental
Perspectives, ed. S. T. Parker & K. R. Gibson. Cambridge University
Press.
Harzem, P. & Miles, T. R. (1978) Conceptual Issues in Operant
Psychology. Wiley.
Herman, L. M. (1987). Receptive competencies of language-trained
animals, In: Advances in the Study of Behaviour, ed. J. S. Rosenblatt,
C. Beer, M.C. Busnel, & P. J. B. Slater. Academic Press.
Herman, L. M. (1998) The dolphin's grammatical competency: Comments on
Elements of Syntax in the Systems of Three Language-Trained Animals,
E. Kako. Animal Learning and Behaviour.
Herman, L. M. Kuczaj, S. A. & Holder, M. D. (1993). Responses to
anomalous gestural sequences by a language-trained dolphin: Evidence
for processing of semantic relations and syntactic information.
Journal of Experimental Psychology: General 122 (2):184-194.
Herman, L. M., Pack A. A. & Morrel-Samuels, P. (1993).
Representational and conceptual skills of dolphins, In: Language and
Communication: Comparative Perspectives, ed. H. R. Roitblat, L. M.
Herman & P. Nachtigall. Erlbaum.
Herman, L. M., Richards, D. G. & Wolz, J. P. (1984) Comprehension of
sentences by bottlenosed dolphins. Cognition 16:129-219.
Hewes, G. W. (1973a) An explicit formulation of the relationship
between tool-using, tool-making and the emergence of language. Visible
Language 7:101-127.
Hewes, G. W. (1973b) Primate communication and the gestural origin of
language. Current Anthropology 14:5-24.
Hewes, G. W. (1976) The current status of the gestural theory of
language origins. In: Origins and Evolution of Language and Speech,
ed. S. R. Harnad, H. D. Steklis, & J. Lancaster. New York Academy of
Science.
Horgan, T. & Tienson, J. (1996) Connectionism and the Philosophy of
Psychology. MIT Press.
Horne, P. J. & Lowe, C. F. (1996) On the origins of naming and other
symbolic behaviour. Journal of the Experimental Analysis of Behaviour
65:185-241.
Jhannesson, A. (1949) Origins of Language: Four Essays. Leiftur.
Jhannesson, A. (1950) The gestural origins of language, Nature
166:60-61.
Khler, W. (1921/1927) Intelligenzprfungen auf Menschenaffen.
Springer. English translation by E. Winter as The Mentality of Apes,
2nd Ed. Routledge & Kegan Paul.
Liberman, A. M. (1993) Haskins Laboratories Status Report on Speech
Research 113:1-32.
Lorenz, K. (1935/1957) Der Kumpan in der Umwelt des Vogels; die
Artgenoe als auslsendes Moment sozialer Verhaltungsweisen, Journal of
Ornithology, 83:137-213 & 289-413. English translation as
`Companionship in Bird Life: Fellow Members of the Species as Releasers
of Social Behaviour' In: Instinctive Behaviour, ed. C. H. Schiller.
International University Press.
Morford, J. P. (1996) Insights into language from the study of
gesture: A review of research on the gestural communication of
non-signing deaf people. Language and Communication 16:165-178.
Morford, J. P., Singleton, J. L. & Goldin-Meadow, S. (1993) The role of
iconicity in manual communication. In: K. Beals, G. Cooke, D. Kathman,
S. Kita, K.E. McCullough & D. Testen, Papers from the Chicago
Linguistic Society 29, Vol 2: The Parasession:243-253.
Morgan, L. H. (1877) Ancient Society. Holt.
Noble, W. & Davidson, I. (1996) Human Evolution, Language and Mind: A
Psychological and Archaeological Inquiry. Cambridge University Press.
Pepperberg, I. M. (1987). Interspecies communication: A tool for
assessing conceptual abilities in the African Grey parrot. In:
Cognition, Language and Consciousness: Interactive Levels, ed. G.
Greenberg & E. Tobach. Erlbaum.
Piaget, J. (1926/1932) The Language and Thought of the Child, 2nd Ed.
Routledge & Kegan Paul.
Place, U. T. (1995/6) Symbolic processes and stimulus equivalence.
Behaviour and Philosophy, 23/24:13-30.
Povinelli, D. J. & Davis, D. R. (1994). Differences between chimpanzees
(Pan troglodytes) and humans (Homo sapiens) in the resting state of the
finger: implications for pointing. Journal of Comparative Psychology,
108:134-139.
Rizzolatti, G. & Arbib, M. A. (1998) Language within our grasp. Trends
in Neuroscience, 21:188-194.
Romanes, G. J. (1888) Mental Evolution in Man: Origin of Human Faculty,
Kegan Paul.
Savage-Rumbaugh, E. S. (1986). Ape Language: From Conditioned Response
to Symbol, Columbia University Press.
Schusterman, R. J. & Gisiner, R. C. (1988) Artificial language
comprehension in dolphins and sea lions: The essential cognitive
skills. The Psvchological Record 38:311-348.
Schusterman, R. J. & Krieger, K. (1984) California sea lions are
capable of semantic comprehension. The Psvchological Record 34:3-23.
Sidman, M. (1971) Reading and audio-visual equivalences. Journal of
Speech and Hearing Research, 14:5-13.
Sidman, M. (1986). Functional analysis of emergent verbal classes.
In: Analysis and Integration of Behavioural Units, ed. T. Thompson &
M. D. Zeiler. Erlbaum.
Sidman, M. (1990). Equivalence relations: Where do they come from?
In: Behaviour Analysis in Theory and Practice: Contributions and
Controversies, ed. D. E. Blackman & H. Lejeune. Erlbaum.
Sidman, M. & Tailby, W. (1982) Conditional discrimination vs. matching
to sample: an expansion of the testing paradigm. Journal of the
Experimental Analysis of Behaviour, 37:5-22.
Skinner, B. F. (1938) The Behaviour of Organisms. Appleton-Century.
Skinner, B. F. (1957) Verbal Behaviour. Appleton-Century-Crofts.
Slobin, D. I., ed. (1985) The Crosslinguistic Study of Language
Acquisition, 2 vols. Erlbaum.
Tervoort, B. T. (1961) Esoteric symbolism in the communication
behaviour of young deaf children. American Annals of the Deaf,
106:436-480.
Thompson, R. F. (1993) The Brain: A Neuroscience Primer, 2nd Ed.
Freeman.
Tinbergen, N. (1948) Social releasers and the experimental method
required for their study. Wilson Bulletin 60:6-52.
Tinbergen, N. (1951) A Study of Instinct, Clarendon Press.
Tylor, E. B. (1868) On the origin of language. Fortnightly Review,
1:22.
Tylor, E. B. (1871) Primitive Culture. John Murray.
Vygotsky, L. (1934/1986) Thought and Language. English translation by
A. Kozulin. MIT Press.
Wallace, A. R. (1881) Review of Anthropology by Edward B. Tylor.
Nature 24:242-245.
Wallace, A. R. (1895) Expressiveness of speech, the mouth gesture as a
factor in the origin of language. Fortnightly Review 64:528-543.
Wundt, W. (1900) Vlkerpsychologie, Vol. I: Die Sprache. Engelmann.
Xitco, M. J. & Roitblat, H. R. (1996). Object recognition through
eavesdropping: passive echolocation in bottlenose dolphins. Animal
Learning and Behaviour 24:355-365.
This archive was generated by hypermail 2b29 : Tue Feb 01 2000 - 01:03:11 PST