In his exploration of facilitation, and facilitative leadership, Roger Schwartz describes and promotes what he calls a "mutual learning model", adapted from work by some acknowledged thought leaders in learning. This learning model can also form the foundation of good collaboration, as Schwartz presents in his article titled Using the Facilitative Leader Approach to Create an Organizational Culture of Collaboration, which he currently makes available on his web site.
When you examine the model, even superficially, there are some interesting elements (e.g. free & informed choice, share all relevant information, discuss the undiscussables) that point to the need for something I call "constructive candor."
It is very hard to collaborate effectively unless everyone involved speaks their mind - but in a way that is productive, contextual, and leads to the agreed upon outcomes.
If you've heard people ask "May I be brutally honest?" - that is not what I'm referring to. Someone being brutally honest is often commenting on something unrelated or overly tangential to the shared objectives, promoting their own agenda, or not willing to take a few minutes and be "un-brutal".
On the other end of the spectrum are people who are not candid at all for a number of reasons, ranging from: fear of repercussions or consequences - often unknown or unpredictable; being ill equipped to respond to a reciprocal challenge or tirade; appearing incompetent in front of colleagues, subordinates, or supervisors; wishing not to disclose a personal agenda (or failure).
Have you ever been to a "collegial" meeting with a number of well meaning people who have wide ranging pleasant, conversations, accomplished nothing, only to immediately launch into a series of one-on-one and small group bilateral conversations about the same topic? I would say there is not a lot of constructive candor going on, nor a lot of collaboration.
Constructive candor takes courage. The courage to do it, because it has significant payoffs in collaborative work. The courage learn and practice doing it, in particular for those who feel it's "not in their makeup." The courage to be persistent at it, since falling back into old habits is all too easy. The courage to live with the personal consequences of candor, which often are not so bad if it's truly constructive.
The bottom line is that if candor is constructive, it generally benefits people, and people certainly don't mind being benefited.