Think Different? Real diversity means getting past groupthink.

Even though most big companies long ago established formal diversity goals and programs, initiatives aimed at creating fresh ideas, planting the seeds of greater innovation and fostering contrarian views that serve as a hedge against costly mistakes, have—with relatively few exceptions—failed.

How is it possible that organizations have achieved outward diversity but not diversity of thought? Perhaps executives and team leaders say they want debate—and may even believe it—but find real-life pushback annoying and impractical, in the same way that every CEO proclaims an open-door policy but few follow through. Or maybe the problem is more fundamental: that the culture works to stifle dissent and push everyone in the same direction.