Why bosses don’t need to know all the answers

June 1, 2011, 5:07 PM UTC

By Linda A. Hill and Kent Lineback, contributors

FORTUNE — Imagine you’re a manager in the IT department and you’re chatting one day in

the corridor with a few software engineers who work for you. One of them turns to you and asks a technical question. After a moment’s hesitation, with all eyes on you, you say, “I don’t know,” and immediately one of the other people provides the answer.

Afterward, you realize that brief episode left you feeling off-balance, as though you’d failed a test in front of the people who look to you for help.

Did you know the answer? Not really. It concerned some recent technical development, one of dozens in your field. You try to keep up, but it’s just impossible. Still, it didn’t feel good.

Can you see yourself reacting that way in those circumstances? Is it difficult for you to say, “I don’t know” or “I’m not sure,” or to ask for information and answers in the areas you manage — the areas you’re supposed to know a lot about?

As the boss, are you supposed to be the one who knows the most, the smartest one, the most able? Is that what people expect of you because you’re in charge?

Probably not, according to internal research conducted by Google (GOOG). A short while ago, the New York Times reported on the results of the tech giant’s Project Oxygen, during which Google analyzed employee performance reviews and feedback to identify common phrases and keywords that were used to describe highly effective managers.

Google’s research yielded a list of eight managerial directives or “good behaviors,” ranked in order of importance. What was least important on that list to being a good boss? Technical expertise.

If you still think you need to be the best and brightest in your area, you probably need to rethink what makes you an effective boss. You were probably promoted because you were truly good at what you did. Perhaps you were the best in the group. Your ability to write better code, or sell more, or come up with better ideas than anyone else didn’t just make you stand out — it defined you. Perhaps that’s how you’ve always defined yourself, first at home with your brothers and sisters, then in school, in sports, and now at work.

No wonder, as the boss, it’s hard to give up that way of thinking. You can tell yourself it’s not your job anymore to know more than anyone else, but you probably find that need still shapes what you do and how you think. It’s so ingrained that that’s just how your mind works.

If so, that’s a problem. As a manager and leader, such thinking can limit and even hurt you.

Ask yourself: Do you hire people who know more than you, or are better than you technically? Or do you find some fault with them in order to avoid hiring them?

Do you compete with those who work for you? Do you find yourself comparing yourself to them in terms of knowledge, skill, and proficiency? Do you find yourself arguing with them, seeking to prove that they’re wrong?

Are you determined to remain as technically knowledgeable and proficient as you used to be? Most managers we know find it impossible to do their work as managers and keep abreast of every development. What if you relied on your people to help you stay on top of things?

Believing you must be the best and brightest in your group will make you a less able boss and limit your team’s performance. It will also hold you back. As you advance, you’ll soon reach a level where you must manage people involved in areas you know little about. What will you do then?

How much do you need to know? Enough. Enough to understand the work, enough to be able to make good judgments about it, enough to understand the common hurdles, and enough to coach or find help for those you manage when they struggle with problems.

You must be knowledgeable and bright, but those areas are not where you are most needed. Instead of being the best yourself, it’s your job to make others the best, to make them productive as individuals and as part of a group. You stand on their shoulders and will rise or fall based on their work. Your group’s success does not depend on your individual knowledge and intelligence; it now rests on your ability to bring out the best in others.

An executive once told us how he learned to deal with his need to be better than everyone else. He imagined himself in the shoes of J. Robert Oppenheimer, who led the Manhattan project that produced the atomic bomb in the late stages of World War II.

Without doubt, Oppenheimer was supremely bright and had made important contributions in the fields of atomic structure and astrophysics. But he gathered and managed a group of world-class geniuses. Would this group have succeeded if he had spent his time trying to prove he was the sharpest tool in that shed? Did he think they all expected him to have the answers to their problems? No, they expected him to create the conditions in which they could find the answers and all succeed together.

Linda A. Hill, a professor at Harvard Business School, and Kent Lineback, a writer with 30 years of management experience, are co-authors of Being the Boss: The 3 Imperatives for Becoming a Great Leader.