Constructive Confrontation: Be blunt with ideas, but kind to people. Politeness is often just a mask for fear.
Book: High Output Management
Andy Grove, Intel's legendary CEO, believed that politeness oftentimes masks fear. People avoid saying what they really think because they worry about offending someone above them.
Therefore, bad ideas survive unchallenged, and bad news cannot be communicated fast enough.
His solution was a practice he called "constructive confrontation." In Grove's words:
"We developed a style of ferociously arguing with one another while remaining friends."
The rule: attack the idea, never the person. You could and should challenge anyone's proposal, regardless of rank. But you are expected to bring data and a defensible opinion to the table.
This only works if the argument stays on the issue and if the culture focuses on reaching the truth as quickly as possible rather than winning the argument.
When teams avoid this, problems usually come back later in a more expensive form.