'Group-think' is when operating in a group distorts your sense of reality. If you have a group of five people and two of them are wrong about something, you only need doubt in the mind of one other person and suddenly you risk creating a majority of people who are wrong.
And since no one likes feeling left out, the group dynamic and longing to fit in is often enough to discourage critical thinking and persuade the other two people to support the majority view.
The same thing happens in matters of taste or judgement, because people don't like to be rude.
Group-think is particularly prevalent when dealing with extreme high or low emotions. So groups will hype up any small victories and have the members of the group thinking they've just changed the world, whereas groups in crisis will often convince themselves that their whole world is doomed.
How to avoid group-think
Photograph: Hero Images/Corbis
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