Of the eight conditions that are the signature of the highest-performing teams, there is one in particular that stands out —in study after study, irrespective of industry and irrespective of nationality—as the single most powerful predictor of a team’s productivity. It is each team member’s sense that “I have the chance to use my strengths every day at work.” No matter what kind of work your team is doing and no matter which part of the world you’re working in, your team will always be most productive when more team members feel delight and joy in what they do every day.

This research from Adam Grant, Francesca Gino, and David Hofmann suggests that introverts can make better bosses—and that extroverted leaders, who sometimes speak first and think later, can actually lose the respect of their team, leading to poorer results. However, any leaders who listen carefully and are receptive to smart and useful suggestions from their team, whether they’re introverted or extroverted, can build the trust required to earn cooperation.

The effects of humble leadership tend to cascade down to the rest of the organization, turning leaders into genuine role models. These effects have been demonstrated in recent studies by Brad Owens from the Marriott School of Business at Brigham Young University and David Hekman from the Leeds School of Business at the University of Colorado. When leaders behave humbly, employees emulate this behavior and display more modesty, admit mistakes, share credit with others, and are more receptive to others’ ideas and feedback. Using data from 607 individuals grouped into 161 teams (both in research labs and in real work environments), the authors demonstrated a social-contagion effect for humble leadership, which enhanced selfless and collaborative behaviors in their followers and, in turn, in team performance.

More precisely, traits such as confidence, narcissism, psychopathy, and charisma advance individuals’ careers without improving the success of the groups they lead. Clearly, we would be better off if we sifted out individuals with such traits, as opposed to rewarding them. The success of teams and organizations is more important than an individual’s personal success, especially when individual victory harms the rest of the group.

The first rule is not to fake anything. You have to be humble, and you can’t pretend to be someone you’re not or to know something you don’t. You’re also in a position of leadership, though, so you can’t let humility prevent you from leading. It’s a fine line, and something I preach today. You have to ask the questions you need to ask, admit without apology what you don’t understand, and do the work to learn what you need to learn as quickly as you can. There’s nothing less confidence-inspiring than a person faking a knowledge they don’t possess. True authority and true leadership come from knowing who you are and not pretending to be anything else.