The feral children cases are certainly interesting, but it is difficult to draw any linguistic conclusions from them for several reasons, the underlying fundamental one being the necessary lack of controlled experimentation. It seems to me that the feral children fall into several categories: (1) children who, once exposed to normal social and physical supports, become remarkably well adapted, including certain skill in language (eg, Kaspar Hauser); (2) children whose skills remain stunted, by either lack of timely exposure to society and language or by inherent disabilities (eg, Kamala the wolf girl); or (3) children whose skills remain profoundly stunted, due to inherent disabilities which might have been the reason they were feral in the first place (eg, Victor of Aveyron, Peter of Hameln). It is difficult to ascertain from the few documented cases whether a particular child's abilities were the result of or the cause of his situation when first discovered by other humans. A child, for example, who suffered from a pervasive developmental disorder would continue to behave in antisocial and nonverbal way, and it is easy to imagine that he was feral because his condition caused him to wander off from his family, fail to seek help when his family was destroyed by disease or other catastrophe, or to be ousted from the family. Of course, in a few cases, we know that the children were seggregated from society for reasons unrelated to thier abilities, and those are the cases in which the children more readily readapted.
Clearly, linguistic abilities depend both on chemical and structural components of our brain and on exposure to language at an early age, but it is difficult to determine the extent to which nature and nurture influence the development of language. Both are necessary, but my own unsubstantiated opinion is that the physical disabilities have a much stronger and more absolute influence than do the social deprivations, assuming all other factors are normal (which, inevitably, they are not).
