The piece is here. Note that in spite of the main case being for creative solitude, Cain acknowledges:
Indeed, recent studies suggest that influential academic work is increasingly conducted by teams rather than by individuals. (Although teams whose members collaborate remotely, from separate universities, appear to be the most influential of all.) The problems we face in science, economics and many other fields are more complex than ever before, and we’ll need to stand on one another’s shoulders if we can possibly hope to solve them.