What Makes a Great Investor?

Greg Mankiw writes: "Hedge fund manager Mark Sellers tells Harvard business students the secrets to success as an investor. An excerpt:

As an investor, you need to perform calculations and have a logical investment thesis. This is your left brain working. But you also need to be able to do things such as judging a management team from subtle cues they give off. You need to be able to step back and take a big picture view of certain situations rather than analyzing them to death. You need to have a sense of humor and humility and common sense. And most important, I believe you need to be a good writer. Look at Buffett; he's one of the best writers ever in the business world. It's not a coincidence that he's also one of the best investors of all time. If you can't write clearly, it is my opinion that you don't think very clearly."