The coolest bosses these days have all left their corner offices behind to work in a bullpen or cubicle where they can interact on an ad hoc basis with members of their teams. Status and respect may never go out of style, but naked power and traditional hierarchies are currently pretty unfashionable in some sectors of the business world. Collaboration and "flat teams" are the new office cool.

For some veterans of the Dilbert-style corporate realities of the past, that's a relief. Author Alexandra Levit, for instance, recently blogged about receiving an email from "a 45-year-old who was thrilled that after more than 20 years in corporate America, he was at last working in a so-called 'open environment.' No more offices, no more cubicles." But can this mania for tearing down walls and flattening business structures go too far?

Yes, suggests new research out of Columbia Business School. The series of studies tested the effects of power hierarchies on team productivity by creating teams with either a mixed propensity towards leadership--in one case some participants were primed to feel powerful by thinking of a time they wielded power over others while others subjects were asked to envision a time they were bossed around before joining the group--or teams made up entirely of hard charging leadership types or participants primed for a meeker, go along, get along approach. In another experiment, rather than prime participants for particular roles, testosterone levels were used as a marker of which study subjects were inclined towards dominating power structures and which less interested in leading.

So did traditional groups of both alpha types and more compliant members do better or worse than groups where everyone was hard charging or everyone was laid back when asked to complete cooperative tasks? The Wall Street Journal's Ideas Market blog sums up the findings:

Groups of participants with varied testosterone levels were better at the cooperative task than groups made up solely of high-testosterone or low-testosterone individuals. The high-testosterone group bickered more--no surprise--which provides a partial explanation for its inefficient work. But, more broadly, hierarchies create defined roles, the authors said, which is helpful in carrying out productivity-based tasks that demand "interdependence."

The importance of defined roles in effective collaboration isn't unique to this study. Well known business pundit Tammy Erickson has also looked into the importance of clearly defined roles in collaboration and concluded they are beneficial to getting stuff done. "Our research has shown that… collaboration improves when the roles of individual team members are clearly defined and well understood--in fact, when individuals feel their role is bounded in ways that allow them to do a significant portion of their work independently. Without such clarity, team members are likely to waste energy negotiating roles or protecting turf, rather than focusing on the task," she has written.

So in other words, if clear hierarchies keep teams from wasting time negotiating roles and battling for turf than they can actually help them get more done more quickly. Though this shouldn't be taken as an endorsement for overbearing alpha male chest beating or deference to authority over good sense, flat it seems, isn't always best. But be warned, traditional power structures aren't a panacea either--especially for creative tasks.

"Creative endeavors would be a different matter… in such cases hierarchies have been shown to prevent some people from speaking up," reports the WSJ, which quotes one of the researchers, Richard Ronay. "It's not a clean picture--that hierarchy is always good or bad. It depends on the type of task,” he says.

Flat teams: do you love them, hate them or have mixed feelings?