Recently, I was seated in a room at a U.S. Air Force base as a class of the best and brightest were listening to an instructor. He was making a provocative argument about a foreign adversary. When he concluded his presentation, the instructor didn’t ask for questions. Instead he demanded a counter argument. He was looking for active disagreement and fearless feedback.

Penalty flags had been placed on tables where the officers were seated. “Throw the flag,” the instructor said. Officers who spoke up would pick up the flag, toss it toward the instructor, and verbally point out the flaws in his argument.

“What was that all about?” I asked the instructor after class.

“This is life and death, Carmine. We don’t have room for mistakes,” he said.

Today’s military officers are being taught that effective leaders encourage open and robust debate. In a paper for Joint Force Quarterly, Dr. Milan Vego, professor of operations at the Naval War College, says “a military organization that restricts or, worse, does not allow free professional discussion is doomed to stagnate in peacetime and to eventually fail in combat.” Vego says that it’s up to commanders to create an environment that fosters “the vigorous struggle of competing ideas.”

Are you fostering the vigorous struggle of competing ideas? Most employees or team members will not speak up unless they are encouraged to offer fearless feedback.

In his new book, How to Think, professor Alan Jacobs says social bonding is cemented in our DNA. Our primitive ancestors had a biological need to be accepted by the group. You didn’t want to be the person thrown out of the cave to fend for himself. We crave social acceptance, which is why we’re reluctant to be the first to question a plan, at least publicly. It’s easier to go with the flow.

“Anyone who claims not to be shaped by [social] forces is almost certainly self-deceived,” write Jacobs. “Human beings are not built to be indifferent to the waves and pulses of their social world.” According to Jacobs, if you want to improve the way you think, seek out smart, sensible and fair-minded people who disagree with your position.

Because the cognitive pull of social acceptance is so strong, leaders must often encourage — even demand — that people disagree. It requires setting aside your ego for the good of the project. I recall working with a top executive at one of America’s largest companies. I had been invited to offer an opinion on his upcoming speech. I sat at a massive conference table with his team of six and listened to the first draft of the speech.

This is painfully boring, I thought to myself. I’m sure someone will speak up right away.

I was wrong. One person said, “Sounds great.” Another said, “Terrific. I think we’re good.”

Am I missing something? I thought. I began to question my own judgment. The pull of social bonding was beginning to kick in. I was going with the flow. But I hadn’t been invited to simply agree with the group. I spoke up: “Hold on, please. We’re not done. The speech has a logical structure, but no emotion, no excitement, no story. I think we can do better.”

The room was silent. You could tell people were having an internal struggle: should they agree with the outsider or should they agree with their boss? The executive then spoke. “I agree. It’s boring. It sounds like the same speech we always give. How do we make it better?” And with that, the team opened up, offering suggestions they had not mentioned earlier. What had happened? In a nutshell, they were given permission to speak up and to offer fearless feedback. They were asked to ‘throw the flag.’

Neuroscientists have found that the herd mentality is very real. We follow the group because it triggers the reward system of our brains. It makes us feel accepted, and therefore makes us feel good. If going with the flow is a habit that’s been cemented in our brains over thousands, maybe millions, of years, then its up to a leader to snap people out of their comfort zones. Putting up a suggestion box isn’t good enough. Asking for feedback isn’t good enough. Leaders must encourage open and vigorous debate if they want to reach the best decisions.

Read article on Forbes.com