An elementary linguistic system?
From all we saw, there are remarkable resemblances among the structures dealt with in “Other restricted systems”: When comparing the behavior of homesigners, twins’ language speakers, and isolated children with that of trained animals as described in “What linguistic abilities do animals have?”, there is a catalogue of properties they share, namely most or all of the ones listed in (42).1
(42) An elementary linguistic system
a. There is a well-marked ability to create a limited stock of form meaning units2 (‘‘lexical items’’).
b. The units are, at least to some extent, arbitrary form–meaning pairings.
c. These units can be combined to produce new meanings.
d. The units are compositional, that is, their meaning remains stable in combinations.
e. The units include items for objects (‘‘nouns’’) and actions (‘‘verbs’’), but also some more abstract items, such as items for colors and numbers.
f. The units can be arranged into propositional structures (‘‘predicate frames’’), even if this ability appears to be fairly elementary.
g. There is also an ability to form sequences of propositions; but there is little to suggest that these sequences are structured in terms of grammatical rules other than simple juxtaposition.
h. There are linguistic means to express questions and negation.
i. There appears to be an elementary ability to comprehend conceptual taxonomic hierarchy (superordinate vs. subordinate category).
j. There are hardly any non-lexical units; communication is achieved overwhelmingly or entirely without functional categories.
k. The system allows for successful linguistic communication among its speakers.
l. There are no clear indications of grammaticalization.
m. If there are any functional categories, they are not created by using parameters of grammaticalization.
n. There is essentially no form of clause subordination.
o. There are no phrase structures that are clearly suggestive of recursion.
p. The system is not normally transmitted from one group of speakers to another (or from one generation to the next).
Taken together, the properties listed in (42) are suggestive of some distinct kind of elementary linguistic system. Note that Casey and Kluender (1998: 74–6) also argue that both deaf children with impoverished language input and some trained non-human primates may represent an inter mediate form of communication in the evolution of language, and com paring twins’ languages with homesigns, Peter Bakker characterizes the latter thus:
These languages appear to be different from adult sign languages, but very similar to the AL’s [twins’ languages; a.n.]. They have relatively free order of subject, verb [and] object, they have many vocatives and sentence final and sentence initial negations and they lack morphology (contrary to adult sign languages). This may point to the fact that we have to do with a ‘natural’ type of language, which emerges in certain situations of deprived language input. (Bakker 1990: 92)
Kaspar and Genie use third-person reference, that is, personal names, for all distinctions of personal deixis (cf. example (40)). This might be seen as an indication that they had a concept both of personal deixis and of incipient grammaticalization; nominal or pronominal expressions having third-person reference do not uncommonly provide a conceptual template for creating categories for second- or first-person reference— the French impersonal pronoun on, which has acquired the significance of a first-person plural pronoun in modern colloquial French being a case in point (see “The first layer: nouns”). But very likely, this behavior is due to factors other than grammaticalization.
But whether the properties listed in (42) do in fact reflect a specific type of elementary linguistic system is a question that we leave open to future research. A clear difference between animals on the one hand and home signers and isolated children on the other consists in their respective non-linguistic abilities, and this difference is suggestive of a dissociation of linguistic and non-linguistic cognitive abilities, as argued for by MacSwan and Rolstad (2005). Kaspar is reported to have become competent in mathematics and to participate actively in philosophical discussions, Genie showed fully developed abilities in the domain of visual-spatial organization, and Chelsea could perform mathematical operations, and she could even keep a balanced checkbook. No corresponding abilities have been reported for trained animals. Since our concern is exclusively with manifestations of language-like behavior, we are not able to offer any interpretation for this discrepancy (but see Curtiss 1994; MacSwan and Rolstad 2005).
1 We concur with Fritz Newmeyer (p.c.) that the database for all these restricted systems is fairly small and that any generalizations should be taken with care.
2 The form these units may take differs from one system to another; they may be spoken words, gestures, lexigrams, or plastic labels.
