Connections outside of our field

I've long been an advocate of reaching outside our own little world to 1) make connections and 2) see how many of those connections become friends. In my never ending quest for learning and, more recently, learning about learning, I am reading a book recommended to me by someone who 1) became a connection in my primary field (the criminal justice discipline) and 2) has since become a colleague and friend.

The book is entitled "Toward Improving PhD Programs." I must say that I avoided reading for some time as I have an all-consuming nature (at least that's what I call the obsessive character trait that causes me to read a book to its conclusion, especially one on a topic I am interested in).

Of interest to me was the passage (p. 124) that says:

. . . graduate students usually associate only with those who are working in their field . . . it would be very beneficial if they could be brought into contact with graduate students who are working in totally different subjects.

What do you think?

Hollis, E. V. (1945). Toward improving Ph.D. programs. Washington, D. C.: American Council on Education.