“We also gave teams a primer on teamwork based on insights gleaned from research in group dynamics. On the one hand, we warned, groupthink is a danger. Be cooperative but not deferential. Consensus is not always good; disagreement is not always bad. If you do happen to agree, don't take the agreement—in itself—as proof that you are right. Never stop doubting. Pointed questions are as essential to a team as vitamins are to a human body.

On the other hand, the opposite of groupthink—rancor and dysfunction—is also a danger. Team members must disagree without being disagreeable, we advised. Practice 'constructive confrontation' to use the phrase of Andy Grove, the former CEO of Intel. Precision questioning is one way to do that. Drawing on the work of Dennis Matthies and Monica Worline, we showed them how to tactfully dissect the vague claims people often make. Suppose someone says, 'Unfortunately, the popularity of soccer, the world's favorite pastime, is starting to decline.' You suspect [they] are wrong. ... Zero in. You might say, 'What do you mean by 'pastime?' or 'What evidence is there that soccer's popularity is declining? Over what time frame.' The answers to these precise questions won't settle the matter, but they will reveal the thinking behind the conclusion so it can be probed and tested.”