In 1971, a Yale psychologist borrowed a chilling concept from the novel "1984" to label a new phenomenon of human behavior.

Groupthink bubbles up when dissenting voices keep quiet. Leaders can improve group decision-making when they work to raise those quiet voices.

Groupthink isn't invisible. If leaders know how to spot groupthink in their team meetings, they can take concrete steps to make sure it doesn't crop up.

The Bay of Pigs Invasion, a political move widely viewed as a textbook case of failed decision-making, has helped psychologists study major organizations.

What causes groupthink? One major factor is the tendency people have in meetings to rush toward consensus, just so the meeting can end earlier.

Groupthink is what happens when team members stop thinking independently, don't speak up, and race toward consensus. But leaders can still avoid it.