This paper reflects the research and thoughts of a student at the time the paper was written for a course at Bryn Mawr College. Like other materials on Serendip, it is not intended to be "authoritative" but rather to help others further develop their own explorations. Web links were active as of the time the paper was posted but are not updated.
Biology 202, Spring 2005 Third Web Papers On Serendip
According to a Chomskyan theory of language, language is foremost a product of the brain. Exposure to a language is required for acquisition of a language, and thus environment and nurture is certainly not left out of the equation. However, this theory proposes that, as a part of being human, a child is born with an innate predisposition to acquire and learn a language.
This biological innateness for language is a result of a language acquisition device (LAD), which Chomsky invokes through the idea of a Universal Grammar (UG). In every child's Universal Grammar there exists a finite amount of linguistic rules. Rules are proposed to be generative and hierarchical as opposed to linear. Syntactic rules then, for example, have deep structures which are then converted into the surface representation as dictated by such rules. Through exposure to any particular linguistic environment, rules are learned and a grammar for that particular language is built. The Universal Grammar acts as a menu, providing potential for all the differing (and contradicting rules) observed throughout the world's languages. A particular linguistic environment thus acts as a switch for selecting which rules apply to the language(s) a child is exposed to and subsequently builds a grammar of rules specific to that language (or languages if the child is in a bi- or multi-lingual environment). This point is easily illustrated in two stages noted as cooing and babbling. At the stage of cooing, a baby produces many different phonetic articulations despite what sounds may or may not be in the phonetic inventory of the surrounding linguistic environment. Sounds which are not represented in the linguistic environment may very well be made by the baby; however, many sounds may be excluded for simple reasons of inadequate motor development and maturation of vocal organs, and is in no way related to what sounds the baby is or is not hearing through his or her environment. The second stage, babbling is distinguishable in that the baby picks up on the phonetic units present in his or her particular linguistic environment. More support for the hypothesis of a UG considers Chomsky's proposal of generative grammar. Rather than children observing, storing, and then imitating sentences learned from adults, a child uses exposure to language to build rules out of the innate UG and then generate novel and, consequently, an infinite amount of sentences. This theory of language acquisition provided by innate universals explains the ease with which babies and children easily acquire any language(s) they are exposed to, and also explains the near impossibility of acquiring native speaker status of a language at a much later adult age. In a innatist view similar to Chomsky's innateness of language, genes also influence and dictate social, emotional, and intellectual. Social, emotional, intellectual, along with language development are all then placed at the same level and are seen as also interacting with each other given environment, but are still however nested in human genes.
Greenspan and Shanker radically refute this model by asserting that symbols, language, and intelligence are not a direct result of genes, but rather made possible by social and emotional interaction with other humans, namely adults. Taking this idea one step further, they assert that social and emotional mechanisms are not as hard-wired as otherwise thought, but are rather made possible by emotional interactions learned very early.
It is important to note that, although Greenspan and Shanker do not place language, symbolic/higher order thinking, and intelligence in the same relationship with genes as an innatist view does, they by no means deny the existence and activity of genes. Just as Chomsky's theory of language acquisition requires a linguistic environment (and therefore experience or nurture), Greenspan and Shanker's theory also involves both sides of the "nature-nurture" model. They acknowledge that genes are required, but emphasize not sufficient alone. As is illustrated with their work with chimpanzees and ideas about brain structure, the mechanisms for basic learning must have evolved and be in place before any individual (or animal) can utilize and take advantage of social and cultural interaction with the environment. As such, Greenspan and Shanker offer co-regulated emotional signaling as the process that opens the doorway for emotional development, language, and intellectual development. Co-regulated emotional signaling involves back and forth interaction, accompanied by emotion, with an adult. Symbolic thinking is reached when the child separates perceived emotions and connects them with meaning in a semiotic way. For example, a child may have incentive to learn the words "baby doll" as a result of emotional signaling between the child and adult (Chomsky's theory of UR however would does not require an incentive, as language acquisition is assumed innately and biologically driven). When the child and adult interact, the child experiences happiness and delight playing with a doll while also interacting with the adult. Later, when the child seeks enjoyment through play or wants the baby doll, she connects the words "baby doll" to express herself. Social and emotional development, then, develop along side each other and give way to (the incentive to learn) language and symbolic thinking (connecting the words "baby doll" with the idea of or physical object) and later intelligence.
Implications for this way of viewing the sequence of different aspects of development are particularly alerting given the assumption on the innatist view that we as babies are predisposed to not only social and emotional development, but also linguistic and intellectual. Greenspan and Shanker's theory holds that such social and emotional signaling is continuously being learned anew by each generation. Greenspan and Shanker concern themselves not just with how such signaling must be passed on by adult generations and learned by children, but also hypothesize about human evolution and the events that lead up to the first group of humans signaling with each other using emotions and symbols. Rather than submitting to the "Big-Bang" hypothesis of emergence of a human species, which looks to a sudden genetic mutation for or natural selection in favor of language, the authors propose that evolution of the human race was a gradual process, as was the very development of emotional signaling and thinking. Though children hit certain milestones in their emotional and linguistic development (first word, building sentences, and so on), their development is gradual (before the first word is uttered, they are still perceiving language from and interacting with adults); so too with evolution.
Claiming that such processes are passed down socially offers an explanation for cultural universals as well as cultural relativism or specificity. That which constitutes an observed universal may be something that came about longer ago in the past (and passed down to a larger population before groups of humans separated and spread out over the globe), while something considered more culturally specific today might represent something being passed down in confines of a specific group. Greenspan and Shanker cite these two types as well; some cultural and learning processes have been passed down over an evolutionary time period (the abilities to relate and signal with emotion) while other processes which are determined by each individual and a shorter time period (the idiosyncratic ways a person deals and relates with emotions). They note, "the former involve basic learning processes and the latter embrace individual content and behavior stemming from these processes." (Greenspan and Shanker, 5)
These processes have continued up until the present day as result of a "snow ball effect." Eventually after our human ancestors begun to utilize these processes, they were passed down successively to each generation over and over. Genes are then not specific for social and emotional development or language; these processes remain manifested only because they are kept in motion through social and cultural transmission from each generation to the next. A child needs not just interaction with human beings but must be taught through interaction with a human, who has already him or herself learned and mastered these processes, in order to utilize the ability to learn these processes.
Work with various species of chimpanzees lead the authors to observe how in dynamic systems (in communities where the chimps are influenced by one another) the chimps can, like humans, demonstrate heightened communicative and intellectual capacities. If human genes are in fact not specific for language, then a species engaged in such emotional signaling should show the same development and heightened processes. And the chimps they observe do. Greenspan and Shanker worked with chimps in groups (and single chimps in isolation to provide a comparison) who were raised in and lived as a community in an environment enhanced by objects which encouraged communication as well as interaction with each other and humans (lexigrams, interaction with humans, etc.). Some might argue that if the chimps were capable of showing similar processes to humans, that a chimp should, like a child, develop the same language. The chimps do develop language in that they, along side emotional signaling, develop symbolic thinking and can communicate with each other. Chimps may just be at a simpler or more elementary stage of emotional processing (which is observed to be passed down to the next generation in the chimps just like in humans) but may not have progressed or learned to utilize higher levels of linguistic and symbolic thinking as humans yet, which does not imply that the chimps are not capable of doing such, they may just not be as far along but on the same track nonetheless.
Greenspan and Shanker's theory raises of course many questions and implications for existing observations for cases of "deviant" development and/or behavior. Cases of feral children, raised in isolation, inevitably demand an explanation in terms of their new model. Followers of the Critical Period Hypothesis, who assume language acquisition is biologically programmed, propose a cut-off (or perhaps a less radical drop-off) of ability to acquire a language natively. Arguers for this hypothesis would predict that such feral children, found after (about the age of) puberty, would never be able to acquire a native language in the same way that a child does. And, as seen in the case of Genie, their prediction is supported. Greenspan and Shanker touch on this case briefly by suggesting that Genie was not able to fully develop language because she was not exposed to emotional interaction. However, she of course after being discovered was in the presence of other people and adults and doubtless had some type of interaction. This might then imply a similar (in part still biologically wired) Critical Period Hypothesis for the simultaneous development of social and emotional interaction, which would of course need to come before any possible proposition for critical periods for language "acquisition" (or better, development). Through their elaborations the authors even offer a better understanding of autism, and provide ways of overcoming aspects of the conditions in children who develop such disorders due to biological deviations. There is no mention of attempted treatment of such disorders in people at older ages and a comparison between the age groups for apparent "treatment" would provide more insight into a critical period hypothesis.
Another situation that seeks explanation through the authors' model is that of Nicaraguan Sign Language. The language was developed by a community of deaf children in the absence of any other sign language. It might be suggested that Greenspan and Shanker's model would not explain this apparent creation of Home sign because the children were apparently "creating" their own language without input from any other language. However, this can be more concretely accounted for than the case of Genie in that the children still had interaction with adults and teachers who had attempted to teach them a manually signed language, thus there were inevitably emotional exchanges of some sort.
Greenspan and Shanker's theory further support for differences between groups and cultures. In their model, both universals and differences are, again, accounted for through the idea of cultural practices being dependent on transmission. Such implications could mean better understandings of the debate between moral absolutism and moral relativism, which would be results of cultural universals and cultural specificities, respectively. A better understanding, sensitivity, acceptance, and embracing of these cultural differences would mean steps forward especially for affairs political in nature and, with a subsequent understanding of cultural memory, a new view of the nature of history.
The authors' ideas lastly raise some concerns about the modern structure of the family and the way in which development through education in children is viewed and handled. If interaction with a caregiver is a requirement of transmission of healthy development, and if there are certainly implications if a child is left in isolation, what are the implications of a caregiver that is not constant? Specifically, how might new understandings change the circumstances for foster care children, who always seem to be uprooted from a family and environment the instance they begin to feel integrated into the new social atmosphere? Furthermore, what might be discovered about the quantity, rather than quality, of child-adult/caregiver interaction? Though an innatist view would similarly require human interaction as a requirement for language acquisition, in the age of information and technology, could there be slight ramifications for parents leaaving their infants and children in front TVs or "Baby Einstein" computers games, when the time might otherwise be spent in real, enriched, nurturing human interaction?
Given that social and emotional development, language and thinking are argued to be relearned anew by each generation and dependent solely on transmission from older generations to the next, the seemingly short time span from one generation to the next seems to allow for very quick change and an opportunity for "things to go wrong." If there are in fact (possibly irreversible) repercussions of certain situations like the above, how long might it take to recognize differences and changes? Could the be changed through younger generations if acknowledged at all?
While both an innate and a interaction-dependent model both require a certain degree of both nature and nurture, neither can provide a definitive answer to the blank slate debate; or at least neither can say exactly to what degree, certain aspects at birth are set in stone or written with experience and/or social interaction. While both provide useful explanations and give helpful insights about aspects of human experience, the less commonly held view of Greenspan and Shanker should be (at least) given as much consideration and attention as a more Chomskyan view, in order to explore what further observations such ideas could lead to and any ways this new kind of model might help in understanding, not only specific conditions like autism, but the very nature of man itself.