When you find yourself thinking about old-fashioned, out-of-touch, hierarchical, siloed organizations, General Motors quickly comes to mind. GM’s bankruptcy and bailout four years ago earned it the nickname “Government Motors,” a reference to both the $80 billion lent by the US government (repaid in full in December, 2013) and to the bureaucratic, top-down management GM executives had used to try to reverse the company’s tailspin. Criticism was also levied at GM’s cars — described as “cookie-cutter” or worse.

When Dan Akerson became CEO in 2010, he brought a bit of daylight into the hallowed halls, breaking down siloes to urge collaboration between departments that had long stopped talking to each other — engineering and parts buyers, product development and purchasing, to name some especially critical relationships. He also centralized IT to remove redundancies and incompatibilities that made teaming across silos nearly impossible. And he put Mary Barra in charge of Product Development.

Passing the CEO baton to Barra tomorrow, Akerson said that she “brought order to chaos” in GM’s vast product development organization, mostly by flattening its bureaucracy and cutting overlapping layers of executives. She had “an ability with people” and a track record of bringing new models to market faster and at lower cost. According to a recent New York Times article, Barra is known inside GM as a “consensus builder who calls her staff together on a moment’s notice to brainstorm on pressing issues.”

Call it instinct, call it talent, it was Barra’s ability to encourage teaming that catapulted her to the top of an organization with 212,000 employees. “What we have here is a culture of team rather than of personality,” Dan Akerson told a Forbes reporter proudly, explaining the management changes. “They play well as a team. That’s part and parcel of Mary’s success, and the rest of the team plays well together, too.”  According to Mo Torfeh, one of her professors at General Motors Institute (now called Kettering University), Barra always had the teaming gene, “She was great in getting jobs done, putting a team together and making sure that it’s being done right. She was always the person who took charge.”

Back in 1999, promoted from then CEO Jack Smith’s executive assistant to head of internal communications, Barra successfully healed GM’s relations with the United Auto Workers after a strike in Michigan. Then-president of UAW Local 22 at the plant, George McGregor said Barra was “a people person, great to work with.” Jump to last year and Barra again demonstrated her appreciation for teamwork by challenging 250 designers and engineers to a paper sailboat race. GM’s Vice President of global engineering, John Calabrese, told reporters that Barra’s goal was to encourage collaboration — and to show that they could have a little fun at the same time.

Bringing teaming into an organization plagued by legacy routines and mindsets is critical to reviving innovation and employee engagement. Most people are waiting for a chance to step up and work on a compelling organizational mission.  Barra’s warmth, compassion, and kindness are often mentioned by colleagues. But it’s just as important to be mission driven and passionate about new possibilities.  Barra’s devotion to great engineering and great products has been breathing new life into GM since she earned the top job in product development in 2011 (just this week, Barra introduced the GMC 2015 Canyon mid-size pickup truck, which she hopes will help grow the more fuel-efficient small truck market).

In today’s successful organizations, the best leaders are those who know how to get others working together.  This is far removed from the old Jack Welch model of taking charge and keeping the spotlight squarely on the boss.  Innovation is always the product of teaming.  Top-down leaders simply can’t get that done.

This blog first appeared on Harvard Business Review on 1/14/2014.

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