Also, critical thinking is a social phenomenon. You make sense of the world based on the sources you trust, and that trust is created gregariously by learning

Also, critical thinking is a social phenomenon. You make sense of the world based on the sources you trust, and that trust is created gregariously by learning to rely on what your peers are sharing as trustworthy. The time and effort needed is shared with the group, and the resulting wisdom of the crowds filters out the most outrageous messages from the outside, developing a 'groupthink' that establishes a consensus of what is "common sense" for the group. However, someone with the power to broadcast messages to the whole group can overcome that group processing, and sway the whole group to a different way of thinking.