"To listen closely and reply well is the highest perfection we are able to attain in the art of conversation."
-- François de La Rochefoucauld (1613-1680)
Interpersonal skills are crucial to project management. There's a lot of literature about them, even a section dedicated to them in A Guide to the Project Management Body of Knowledge (PMBOK ® Guide) --Fifth Edition. Still, some of us think it is too much work to improve on an interpersonal level.