Richard Muller, a professor of physics of UC Berkeley, gave a great response on Quora to a question about majoring in the three fields of math, computer science, and physics. He wrote in length about the need to have a variety of skills. It reminds me of Robert Twiggers‘ emphasis on what he calls polymathic synergy (1 and 2). He cited Robert Root-Bernstein on the varied interests of Nobel Laureates:

Almost all Nobel laureates in the sciences actively engage in arts as adults. They are twenty-five times as likely as the average scientist to sing, dance, or act; seventeen times as likely to be a visual artist; twelve times more likely to write poetry and literature; eight times more likely to do woodworking or some other craft; four times as likely to be a musician; and twice as likely to be a photographer.

That’s a pretty big difference.  

Muller says basically the same thing:

To be really productive in your future life, you will need a broad range of skills. You can’t learn them all as an undergraduate; 4 years is way too short. All that can really happen is that you can get a good solid introduction to a wide range of fields, and that will enable you to develop them over the coming decades.

If you triple major, you will not have room in you schedule to take electives in courses that could trigger a life-long learning in the breadth of fields that will likely prove invaluable to your career.

And he adds how his ability to write clearly has helped him in his own career, writing grant proposals, journal articles, and books. In fact, it was his clear writing in a journal that led to Addison Wesley asking him to write a book on the same topic.