Michael Erard's book "Babel No More: The Search for the World's Most Extraordinary Language Learners" is high on my list of books to read. I haven't gotten to it yet, but it has had quite a bit of media coverage, bringing out more research and information about how and why some people are driven to learn many languages.
This recent NY Times article about a teenager in New York City and the YouTube videos he uses to reach out to speakers of the 15+ languages he speaks, also touches on the question of whether this kind of talent is innate or learned.
The answer, neurolinguists are now discovering, is a bit of both, said Loraine Obler, a linguist and a professor at the City University of New York who has studied bilingualism’s effect on the brain. “There are people whose brains are set up to do language learning,” she said, “the same way some people are more talented at drawing.” Also, she added, “The brain’s ability to absorb increases as we know more languages. Having a second language at a young age helps you learn a third, even if they’re unrelated.”
It is nothing short of a miracle that we learn language at all. Our brains and our societies are structured to support this. But people have all kinds of talents. Certainly practice will improve skills, and innate talent added to this will bring excellence.