Depressing, but also intellectually interesting. The recent accendancy of 'nature' people in the popular press and their genetic explanations for damn near everything (much of it probably hogwash, imho) is greatly discredited by the simple fact that people, as we normally think of them--speaking, feeling, thinking as we think of it--are not born but are nurtured into existence by their interaction with others. Hardly a blank slate, but hardly a hardwired machine, either. I think it relates the way that Wittgenstein approaches thought and language in Philosophical Investigations; among other things, that since any truly inarticulate thought cannot be shared it might as well not exist, and that language must be acquired by a sort of training with other people and instruction in everyday life. Feral children think, certainly, but not in the way we're used to talking about 'thinking.' It also says something about the inaddequacy of any atomistic conception of the individual. No man is an island, and all that.
But them I'm probably abstracting this a lot to avoid just how horrible it actually is.