What it is:
The more people speak up in favor of one view, the more others agree and it becomes less likely that someone will speak out.
As humans, we are social beings and we don't like conflict -- we want to preserve a positive group dynamic.
How to address it:
It’s difficult to break away from groupthink, but it may be helpful to present counterarguments as “what if” questions. Frame disagreement as playing devil's advocate; you want to make sure that all possible outcomes are being considered.