Are great marketers born or made?

For many marketers can be both born or made, but for the rest the answer could be just one. However, the title can be discussed under the theory of Leadership, such as if a great leader born or made by its environment?

A study made by Steve Martin at the Harvard Business Review in 2011 concluded that 70 percent of a successful marketer who has the talent is since birth, and 30 percent of successful marketers learn are made.

Though, one is not required to have a "born talent" of becoming a marketer since he or she are able to learn the science of marketing from sources, such as books,...