What do the Cases of “Feral” Children Teach Us About Nature vs Nurture?

The unanswerable question, is it nature or nurture that define who we are? Looking at the few incidences of "feral" children gives further insight into attempting to answer this question. A commonality between all of them is that they do not know language and for the most part are unable to learn it. On rare occasions, if they are taught the basics of language before becoming "feral," they stand a chance at learning more, but never can obtain the full vocabulary of a "civilized" person. What does this say about nature vs. nurture? Is it nurture that allows us, or teaches us, to speak? Well it could be said that nature gives humans the capacity to learn language, but it is only through nurture that we can acquire language. In the case of the Ukrainian girl who lived with dogs from the age of three to age of eight, through nurturing from the dogs, she learned to bark and growl just like them. In all cases where the child is "taken in" by animals, they imitate the animal's sounds and behaviors. This points to nurture as the predominant influence on making humans who they are because it is obviously not in our nature to bark or growl. So which factor determines who humans are, nature or nurture? I couldn't honestly tell you, however, in looking at "feral" children, it seems to me that nurture does indeed have a good amount to do with it.