By Marshall Goldsmith

Reputation is an important element in establishing your Mojo. It’s where you add up who you are (your identity) with what you’ve done (your achievement) and toss the combined sum out into the world to see how people respond. It seems, however, that many of us neglect our reputation. It’s not that we don’t care; we care a lot. But we confuse our need to consider ourselves to be smart with our need to be considered effective by the world. The two are not the same thing, and one often overwhelms the other.

One of the most pernicious impulses among successful people is our overwhelming need to prove how smart we are. It’s drilled into us from our earliest school days, when we’re graded and ranked in a winnowing process that separates the average from the smart from the super-smart. It continues through high school, college and graduate school. And we continue this competition into the workplace, although our “report cards” now come in the form of promotions, paychecks and praise rather than test scores. We want our bosses and colleagues to admire our brainpower.

It’s pernicious because the need to be the “smartest person in the room” often leads to some incredibly stupid behavior. It leads to dumb arguments, in which we fight to prove that we’re right and someone else is wrong. It’s the reason we feel to need to tell someone who shares information with us that “we already knew that,” though it devalues them. It’s the reason we fight to the death to defend an opinion that has worn out its welcome.

Frankly, it’s the reason that so many of us are such poor listeners. We’re so invested in presenting ourselves as smart that we believe we don’t need to hear everything that people tell us. We think we’re so smart we can tune out people and still succeed.

Not everyone behaves like this. There are people who are willing to sacrifice the fleeting buzz of needing to be smart for the more valuable feeling of being effective: of delivering on time, of bringing out the best in others, of finding the simplest route to a solution.

To find out which side you fall on—smart or effective; consider this hypothetical Brain Pill Question:

You are offered a Brain Pill. If you swallow this pill, you will become 10 percent smarter than you currently are. However, to everyone you know and to those you meet in the future, you will seem 20 percent less intelligent. In other words, you will become smarter, but the rest of the world will see you as dumber. Do you take the pill?

Your answer says a lot about how you value your reputation. A lot of people would take the pill, happy to have the added smarts, and to hell with the world’s diminished opinion.

We’re often faced with this choice. Remember this the next time you face an important career decision. If we’re clueless about our reputation, we’re less likely to think about the long-term impact reputational impact of our choices. We’re often thinking short-term instead. Is this a decision that gets my boss off my back or brings in some quick cash, rather than enhance my reputation for being effective in the long term? These are entirely different measures. And from my experience, choosing to be effective rather than smart ultimately pays off in terms of our reputation, our achievement, and our Mojo.

Excerpted from Mojo: How to Get It, How to Keep It, and How to Get It Back When You Lose It!.

Dr. Marshall Goldsmith has authored 28 books including What Got You Here Won't Get You There - a New York Times best-seller, Wall Street Journal #1 business book and Harold Longman Award winner for Business Book of the Year. Succession: Are You Ready? is the newest edition to the Harvard Business 'Memo to the CEO' series. Marshall's latest book is Mojo: How to Get It, How to Keep It, and How to Get It Back When You Lose It!