Recognizing "when your greatest assets turn into career-limiting liabilities" isn't easy, writes Jake Breeden, since "human nature, social norms, and corporate culture can all pull us toward the territory of unexamined virtues." A faculty member at Duke Corporate Education, a nonprofit executive-development offshoot of Duke University's Fuqua School of Business, Breeden has worked with managers at Microsoft (MSFT), Cisco (CSCO), Google (GOOG), IBM (IBM), and elsewhere on identifying the blind spots that hold them back. Now he's written a book about it,Tipping Sacred Cows: Kick the Bad Work Habits that Masquerade as Virtues.

The sacred cows he's referring to -- all desirable in unlimited quantities, says the conventional wisdom -- are balance, collaboration, creativity, excellence, fairness, passion, and preparation. "When leaders embrace beliefs without understanding and managing the potential side effects, the beliefs become sacred cows," Breeden writes. Like the wandering herds that clog the streets of Japiur, they get in the way of progress. Consider, for instance, creativity. Analysts scratching their heads over why Sony (SNE) hasn't produced a hit product since the last century tend to blame the company's supposed lack of creativity. Breeden believes that just the opposite is true, and that Sony's "failures stem from too much creativity" -- or, more precisely, from creativity's dark side, arrogance.

"Instead of listening to the market with humility, Sony's engineers crammed their best technology into an MP3 player that was too cumbersome to use. Instead of taking care of their customers' need for simplicity, they took care of their own engineers' need for complexity," Breeden writes. "Engineers inside Sony viewed the hard disk technology used in Apple's iPod as beneath them, so they went their own way. These innovators had brains full of ideas. Their problem wasn't too few ideas. Their problem was too much narcissism."

Or take excellence, companies' Holy Grail, particularly since the publication of Tom Peters and Robert Waterman's In Search of Excellence. The evil twin of excellence, Breeden believes, takes over when the people in charge confuse the process with the outcome, because getting to a great result requires embracing some chaos and uncertainty along the way. "When leaders demand perfection even in the unimportant details of their workday, they waste emotional and intellectual energy," he writes. "Leaders too often demand excellence in small things because they lack the will to prioritize what matters most."

Tipping over that particular sacred cow, Breeden says, takes a willingness to dive in and make mistakes, as in what Mark Zuckerberg has called Facebook's (FB) "hacker ethic." As Zuckerberg wrote in a letter to shareholders, "Instead of debating for days whether a new idea is possible or what the best way to build something is, hackers would rather just prototype something and see what works."

Or look at Pixar, where animators routinely share unfinished scene sketches, including "very rough work that may not turn into anything usable," Breeden writes. "Each animator embraces the mess of progress, just as each one understands that there is no compromising on the quality of the finished product ... You must lower the day-to-day standards of work so that you can achieve the absolute highest standards at the end." Breeden's book offers practical advice on how to tame each of the sacred cows he sees as blocking people's best performance, but the exact point where a virtue goes bad is not always obvious. Curious about whether one of them might be holding back your own career? You can take a 21-question quiz at breedenideas.com/assessment.