Few things leaders can do are more important than encouraging helping behavior within their organizations. In the top-performing companies it is a norm that colleagues support one another’s efforts to do the best work possible. That has always been true for pragmatic reasons: If companies were to operate at peak efficiency without what organizational scholars call “citizenship behavior,” tasks would have to be optimally assigned 100% of the time, projects could not take any unexpected turns, and no part of any project could go faster or slower than anticipated. But mutual helping is even more vital in an era of knowledge work, when positive business outcomes depend on creativity in often very complex projects. Beyond simple workload sharing, collaborative help comes to the fore—lending perspective, experience, and expertise that improve the quality and execution of ideas.

A version of this article appeared in the January–February 2014 issue of Harvard Business Review.