Bill Croft
University of New Mexico, USA
Language is often considered to be a unique defining characteristic of human beings. However, other species have communication systems, and it is necessary to be more specific about what makes language unique to humans. Language plays an essential role in the successful achievement of cooperative joint actions between human beings, and it is the latter that is unique to our species.
Joint actions involve two or more individuals coordinating their individual acts in order to achieve a common goal. Coordination of individual actions is difficult, but it is greatly facilitated by the ability to communicate one’s individual intentions to the other participants. Communication itself is a joint action: it succeeds when the receiver recognizes the intention of the communicator. Communication also requires coordination, and coordination of communicative intentions is difficult because we cannot read each other’s minds. A powerful coordination device to solve this coordination problem is convention. Language is a conventional system for communication, which in turn allows human beings to coordinate joint actions.
A convention, for greeting, is a regularity in behavior—such as shaking right hands—which is partly arbitrary and common ground (shared knowledge) in a community, used as a coordination device for a recurrent coordination problem—such as greeting each other. Linguistic utterances are also conventions. Producing a string of sounds such as butterfly is a regularity in human behavior, which is partly arbitrary (one could have said mariposa instead, for example) and common ground in the community (English speakers, but not Spanish speakers); and it coordinates the recurrent coordination problem for the joint action of communicating something about a particular class of insects.
The central properties of human language follow from its role as a conventional system for communication. Language is fundamentally symbolic: it pairs form (the regularity in behavior) with meaning (the recurrent coordination problem). Language is also fundamentally arbitrary, and the arbitrary symbols it employs are particular to each speech community.
The systematic nature of language follows from the fact that language is a general-purpose set of conventions for communication. Speakers use language to convey an indefinite range of experiences. These experiences are each unique but they can be analyzed into parts that are recurrent (different experiences involving butterflies, for example). In the same way, linguistic utterances are complex in structure but are made up of recurrent parts: words, inflections and constructions. Language has a further level of organization in its sound system. The richness of experience requires a very large number of words, and the sound structure of words can also be analyzed into parts that are recurrent (the different types of sounds, such as different consonants and vowels). Thus, the sound structure of words is complex but also made up of recurrent parts: the particular sound segments.
Language therefore operates at four levels in all: (1) joint actions; (2) the communication of intentions to coordinate the joint actions; (3) the formulation of conventional linguistic expressions to coordinate communication; and (4) the production of a string of sounds that constitutes the conventional linguistic symbol. The linguistic system, levels (3) and (4), is often treated as an autonomous entity, but it exists only to serve the function of communication (level (2)) and ultimately joint action (level (1)). For example, language is only one coordination device for communication, and is always enriched by other coordination devices, such as bodily gestures and joint attention. Therefore, language does not itself represent everything a speaker wishes to communicate. Language (and gesture) only evokes what is to be communicated. The full communicative intention is fleshed out by the common ground of the speaker and hearer: their shared knowledge, including the current context of the speech event.
Although human languages are extremely diverse in their grammatical structure, there are many core features they have in common, in particular a hierarchical organization such that utterances are made up of clauses, and clauses are made up of a central predicate (usually a verb) and a set of dependent phrases (subject, object, etc.). This structure emerges from the psychological process of verbalizing an experience. A speaker begins with a whole, unique experience, and subchunks it into smaller chunks. These chunks correspond to clauses, which are grammatically linked in various ways (coordination and subordination). The chunks/clauses are then analyzed by extracting the participants, which correspond to the dependent phrases; what is left is the predicate denoting the situation to be expressed. The grammatical structure of the clause expresses who did what to whom in the chunk of experience. Finally the participants and the event are categorized into general types; the categories correspond to words and their part of speech (nouns, verbs). The grammar of phrases picks out the specific individuals and the specific event that the speaker intends to communicate to the listener. Verbalization is also flexible, allowing for alternative conceptualizations of the experience to be communicated.
The social and psychological processes underlying language are exceedingly complex. One consequence of this complexity is that language is highly variable. The process of verbalization generates variation in how an experience is described—two people describing the same experience will not use exactly the same words and grammatical constructions. This variation in language use/behavior is monitored by speakers and forms a part of their knowledge about the conventions of their language. In some cases, the variation becomes associated with particular social groups and acquires a social value: it is ‘prestigious’, ‘vulgar’, or ‘cool’. Once a linguistic variant acquires a social value, it can then be propagated through the speech community (or conversely, go extinct in that community), following the community’s social structure and the social forces which shape it. This two-step process—generation of variation, and propagation through the speech community—is language change, and it conforms to the principles of evolutionary models of change. When speech communities diverge, as happens constantly in human history, language changes in each daughter community lead ultimately to linguistic diversity. However, recent social processes—conquest, colonization, globalization—are leading to a massive extinction of languages and the cultures embodied by them.
