There's a lot golden in this interview with Pixar president Ed Catmull, but the thing I want to highlight is this bit on the idea of honesty as "an abstraction easy to ignore" in the creative/collaborative process:

They don’t want to walk in and embarrass themselves, they don’t want to say anything stupid, they don’t want to offend anyone, so these personal pressures and responses start to emerge. […] And it’s a personal thing. So we have to change the dynamic. When we have something tricky and that’s holding things back, we have to have a four person or five person meeting, where the dynamics are different. And sometimes where things are actually going pretty well, then you want to have a room of 25 people, see how it works, and let them express themselves and have them grow. But if you have 25 people in the room some of them then start to perform, rather than participate. So there is this balance, what is the state of the thing… we need to have honesty, we want to have honesty, but honest is a buzzword. Its one of these things we hear, everyone nods their head on, ‘it’s all true’, [but] the gap between the abstractions and where people actually do it is enormous. And people fill it in with all sorts of crap.

In most workplaces I doubt you even need 25 people for this to start happening.