Burling (1999) raises three questions about the cognitive prerequisites of language. We suggest that the prerequisites of language were changes in motivational system. Nonhuman animals do not have a language similar to human languages, because this is not necessary to serve their limited system of motivations. Language emerged when the human system of motivations became able to support long-term goal-directed processes with no innate basis. A possible scenario for this process is considered.
2. The conventional view of language is that it is a means of communication. This definition is correct but incomplete: language is a means of communication for people engaged in a joint activity, real or even imaginary. There is a clear correlation between the diversity of activities and the complexity of the language serving these activities. Modern languages such as English, Russian or Arabic consist of hundreds of thousands of words only because these languages are applied in thousands of diverse activities. The languages of hunter-gatherers were probably limited to hundreds of words (Vedenov, 1988). Each human activity has a certain goal, hence, the complexity of languages is a consequence of the ability of the human brain to construct diverse goals. Indeed, most human goals are not constrained by any innate basis; they are social, and result from various interactions between people. The brain is able to pursue goals as long as is necessary, and this is very important for developing languages: only after a relatively long period of usage will new words or other new constituents of the language invented by a single man or a small group be accepted by most speakers, thus becoming part of the language. So, there is an obvious connection between language and the ability to construct and maintain long-term motivations with no innate basis.
3. No nonhuman animal seems to have a motivational system with similar characteristics (Hinde, 1970). Of course, animals have long-term motivations (e.g., sex, hunger, and thirst), but these are all innate. An animal can form learned motivations, but only when one of the basic drives is activated (e.g., a hungry chimpanzee can use branches as tools but does not store them for another day; Fabri, 1976). With the limited and stable number of long-term motivations, animals are constrained in using and developing their languages. Since all their motivations are connected with vital functions, any serious misunderstanding in the process of communication can be fatal; as a result, the number of signals in animal languages must be small and the signals must have unequivocal meanings. On the other hand, even if animals "invent" new signals such as the chimpanzee pokes considered in the target article, such signals are used only for a short period when a corresponding goal controls behaviour. This period is insufficient to make the signals shareable for an entire group. Roughly speaking, nonhuman animals do not have a language similar to human languages because they simply do not need it.
4. The ability to construct and maintain long-term motivations with no innate basis was the most important prerequisite for language. Language emerged when early humans became able to form and sustain goal-directed processes for relatively long periods (e.g., for several hours). Of course, such processes were grounded in innate drives; however, they had stable goals of their own or a hierarchy of goals. When a group of early hominids participated in such an activity, the members formed new signals by altering innate ones, and used them in interactions important for achieving certain goals. Inevitable misunderstandings were not critical because most of these goals were only intermediate and interchangeable. On the other hand, after frequent repetition, some effective signals could be shared by the entire group, thus keeping their meanings constant for hours. Evolution further selected the individuals who were maximally able to invent and display new signals, repeat the signals of other people, and memorise and retrieve such signals, for such an ability was very useful in collective activities which are much more efficient for survival than individual ones. There was a reciprocal effect: the ability to communicate effectively allowed a group of early humans to achieve more long-term goals. Examples of long-term collective activities which were important for ancient hominids include the ability to hunt as a group, collective self-defence when under attack by other groups, complex forms of gathering, and women gathering while men transported provisions to the camp. The system of motivations eventually became independent of innate drives, while on the other hand primitive signals developed into language. An additional effect of this process is that speech plays a very important role in self-regulation and self-control.
5. Some authors have reported that the prefrontal lobes of apes are able to maintain working memory functions only while activated by innate drives such as hunger (Batuev, 1981, Inoue, Oomura & Aou, 1985, Thorpe, Rolls & Maddison, 1983). We propose that due to a genetic mutation, the prefrontal lobes of early humans remained active without influencing innate drives or emotions, through a complex process of reverberation (Prudkov & Rodina, in process). This provided the basis for the ability to construct and maintain long-term motivations. Unlike biological drives, the ability is not a specific property of the motivational system, as hunger or sex is, it arose from changes in the prefrontal cortex supporting the system of working memory, and these changes could influence other cognitive processes because the prefrontal cortex is involved in various ones (Luria, 1973). In other words, changes of the cognitive and motivational processes connected with the functions of the prefrontal cortex is our answer to the first two questions raised by the target article regarding the prerequisites of language.
6. Unlike Burling, we do not suggest that the four cognitive capacities mentioned in the target article (a rich understanding of the external world, inference of referential intentions, icons and indices, and imitation) must all have developed before word learning could begin. It is reasonable to assume that some of them could evolve together with language because the ability to maintain long-term processes underlay the evolution of both language and these capacities. On the basis of this, it is possible to explain the relationship between language and cognitive capacities.
7. Those who have participated in collective goal-directed activities will probably be familiar with a by-product of such activities, which can be referred to as the lowering of the understanding threshold. After continuous work, one word, gesture or even one movement of another person can convey the same amount of information as an entire proposition. This is a reflection of the fact that a joint activity of several people establishes a common set in their brains. The same mechanism probably facilitated the cognitive processes of our ancient ancestors. It is not difficult to infer the intentions of another person when both positions are similar and there is a common goal. Under these conditions it is easier to understand the meaning of signals and the action of one person can be spontaneously repeated by another. Changes in these cognitive capacities were useful in collective activities, and evolution would have preferred the individuals with such changes. On the other hand, these alterations were useful for developing language, which could itself be a means for selecting individuals with the capacities required. As a result, language and cognitive capacities could support each other in the process of evolution.
8. The evolution of word meanings most likely consisted of three stages. At the first stage, the brain of ancient humans was already able to memorise information relevant to reaching a goal and retrieving it from memory over a long period. For example, when one participant of a hunting expedition saw an antelope, he was able to "inform" another participant of this in an hour by displaying signals associated with the state of excitement. This ability was a consequence of new properties of his working memory, which became less susceptible to various 'distractions' inevitable in complex and long activities. At this stage, however, the process of communication was dependent upon a perceptual context and active drives, because the linguistic system was a component of other cognitive processes. This means that the hungry members of a hunting expedition could "discuss" antelopes only if they saw those antelopes prior to the onset of the "discussion".
9. At the second stage, the linguistic system of ancient humans became independent of perceptual contexts, but still depended on drives, emotions or other long-term factors which provided a necessary level of brain activation (analogous to the cognitive processes of animals). As a result, ancient humans became able to "talk" about the goal, and participants of future hunting expeditions (at the prior stage such actions had no initial goal; each participant was motivated by drives). At the last stage, the meaning of words was already independent of any form of ongoing context. Taking into account that the combination of several signals contains more information than a single one, it is reasonable to assume that primitive forms of sentences were already in use at the first stage.
10. Amongst the various theories of language, one suggests that all human languages are based on a universal syntactical model ("Universal Grammar"), which is coded at the genetic level (Chomsky, 1995, Pinker & Bloom, 1990). It is very difficult, however, to imagine how evolution could construct an innate set of rules invariant with respect to the infinite diversity of human activities, since even human thinking is probably domain-specific (Piaget, 1972). On the other hand, a grammar which could arise from a limited set of human behaviours would also be unable to serve this diversity. It is incorrect to suppose, however, that language is merely a consequence of complicating human cognitive machinery (Gould, 1977). The above analysis demonstrates that language was an inevitable result of changes in human motivations. We suggest that humans only have a potential for speech which enables children to learn the language that is spoken around them. The architecture of this linguistic system is very complex and probably includes many interdependencies and interconnections. As a result, after acquiring a language, the linguistic system can be in only one of several possible states. This is the reason there is a similarity between different human languages.
Burling, R. (1999) The Cognitive Prerequisites For Language: Target Article on Language-Prerequisites PSYCOLOQUY 10(032). ftp://ftp.princeton.edu/pub/harnad/Psycoloquy/1999.volume.10/ psyc.99.10.032.language-prerequisites.1.burling http://www.cogsci.soton.ac.uk/psyc-bin/newspy?10.032
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