“Men, it has been well said, think in herds; it will be seen that they go mad in herds, while they only recover their senses slowly, and one by one.”
"Extraordinary Popular Delusions And The Madness Of Crowds" (1841)
This famous photo shows just one guy stood with his arms crossed, whilst the rest of the crowd deliver the Nazi salute. It seems that entire communities and cultures can sometimes travel far in the wrong direction blindly and happily, until individuals start standing out, or contact is made with outside cultures, which cause the masses to slowly, one by one, come to their senses. The first ones to start up and say "this is wrong!" are doing the hardest job of all.
Errors in Thinking: Cognitive Errors, Wishful Thinking and Sacred Truths - read up on the social causes of poor thinking.