Why do some people get all the plum assignments, the big raises, the fast-track promotions? It's not that they're more intelligent than their colleagues, or better leaders or smoother schmoozers. In fact, most of them don't work any harder than the poor schmo in the next cubicle.

What makes these people office stars, says Robert E. Kelley, 47, a management consultant and professor at Carnegie Mellon University's Graduate School of Industrial Administration, is that they work smart. For his new book, How to Be a Star at Work (Times Books), Kelley studied the winning strategies of hundreds of workers from Bell Labs and 3M. PEOPLE contributor Kristin Wintermantel asked Kelley, in his Pittsburgh office, to explain his findings.

What are office stars?

Stars are the small handful of people in any work environment who outproduce and outshine everyone else. They contribute so much more value to the bottom line that they're often referred to as 10-for-1-ers, meaning that one of them is worth 10 average workers. In most organizations, between 10 and 15 percent of the people are stars.

What was your most surprising finding?

That stars aren't innately superior to everyone else. We gave hundreds of star and average performers IQ, personality, work-attitude and social-skills tests. We thought for sure that some differences would turn up, but there were none. So we started following people around, watching how they do the job. That's when we hit pay dirt.

So what makes a star?

It's the strategies the person uses to approach his or her work. An important one is initiative: identifying unassigned work that is critical but is no one's responsibility—like upgrading your company's computer software—and saying, "I'll do it." Too often, average performers take initiative only for tangential things, like volunteering to organize the company picnic.

Another star strategy is networking, which means identifying the knowledge you need to get your job done and building dependable two-way streets to the experts. Stars get the right answers, fast. Average performers often turn to the wrong people for information, so they end up spinning their wheels longer.

What are some other strategies?

There's self-management: thinking about what work is really important. Instead of checking things off your to-do list, worry about what should get on your to-do list. And it's not just managing your project, it's managing your whole life at work. Stars constantly think, "How do I make myself more valuable? What kind of experiences and skills do I need to get?" They know it's their, responsibility, not the company's responsibility.

There's also perspective. Stars realize they have to understand multiple points of view, and ask themselves, "How does my boss think about this? The customers? The competitors?" Average performers have tunnel vision.

Are stars workaholics?

No. People think that if you want to be a star you've got to give up your outside life. But we found that stars often work less than average performers, because they have learned how to do more and better work in less time. This isn't true of all—some stars are workaholics, but then there are average performers who are workaholics too. The difference is that stars have the choice.

You're skeptical of today's emphasis on leadership. Why?

Our society is so leader-oriented that many people think to follow is to fail. But I found that 80 percent of us spend 80 percent of our time as followers. Stars learn early that it's not always important to be the one making the score; making the assist is often more valuable. They also realize that if you help other people succeed, they're going to help you.

Given how often people change jobs today, why strive to be an office star?

First, because it gives you the satisfaction of knowing you're really great at something. Second, because it increases your options. If you're a star, not only are you less likely to get downsized, you also increase your odds of being in demand on the outside. So it's a kind of insurance policy.

Can anyone become a star?

Theoretically, yes. When we taught 300 employees [at Bell Labs] the key strategies that stars use, their usual productivity improvement rates doubled by the next year, on average. Stars are made, not born.