We often assume that the people most likely to zoom ahead within organizations are the ruthless, pragmatic types who are all about No. 1: People always looking for ways to benefit themselves. “Operators” who try to derive maximum gain from every workplace transaction.

According to Adam Grant, that assumption is dead wrong. Grant, at 32 years old, is already a major star in the world of organizational psychology. He is Wharton’s youngest full professor, and has consulted for clients that include Google, the NFL, Goldman Sachs, and the United Nations. His first book, Give and Take, was released last year and soon became a New York Times best-seller. In short, he’s one of those hyper-successful types who we might imagine fiercely clawing his way to the top with little regard for others.

Yet Grant’s approach is precisely the opposite. He tries to be as generous and selfless as he can. A profile of Grant in the New York Times Magazine last year detailed his superhuman efforts to help other people. And his research—as laid out in his book—suggests that, contrary to conventional wisdom, nice guys actually finish first.

Grant divides the typical workplace into three types of people: takers, matchers, and givers. Takers are those selfish folks who always have a sharky angle and forever put their personal interests ahead of everybody else’s. Matchers (the bulk of us) view the world in terms of fairness and balanced ledgers—I scratch your back, with the unstated but firm understanding that at some point you will scratch mine. Givers, by contrast, perform all sorts of selfless acts with no expectation of reciprocity. They tirelessly pitch in for their colleagues, eagerly mentor their underlings, and regularly prioritize other people’s needs above their own.

You might guess that givers—while lovely people—lack the sharp elbows required to get ahead in corporate America. And, to some extent, you’re right. Grant acknowledges that studies reveal many givers tend to linger at the bottom of the food chain, with low promotion and productivity rates. They fail to excel because they’re too busy helping other people do just that.

But though they’re overrepresented at the bottom, Grant’s most interesting finding is that givers also climb to the top. You’ll find givers massed at the two ends of the spectrum, with takers and matchers in the middle.

Why is this? Grant suggests that takers may temporarily succeed, but once found out they pay a hefty price. Most people are in fact eager to punish folks they perceive as takers: Studies show that we’ll choose to sacrifice our own gains if it means seeing justice meted out to someone we deem piggy.

Matchers don’t suffer in this way as a result of their attitudes. But they also don’t benefit. As Grant has written, “matchers often leave a transactional impression, as if they’re always keeping score.” We know where we stand with matchers, and for the most part we respect their moral code, but we grant them no particular credit for their behavior.

Meanwhile, givers construct valuable networks out of all the grateful colleagues who correctly perceive them as selfless and agenda-less. Givers share credit without demanding any in return, which spurs co-workers to flock to their projects. Their generosity earns them deep and lasting respect, which translates into potency. When a taker suggests an idea, others are naturally skeptical—what’s in it for her? But when a known giver has a notion, people are willing to get on board out of a sense that it must come from a place of genuine good will. What’s more, Grant argues, givers’ justified sense that they are contributing to a greater good helps keep them motivated and fulfilled in their work, which in turn improves their output.

What separates the losing givers at the bottom of the pyramid from the winning givers at the apex? Grant has some theories about this. First: The winners learn how to give without letting themselves become doormats. They do favors with no strings attached, but they don’t overextend themselves to the point that they fail to achieve their own goals. Second: Winners’ giving is more widely distributed—lots of quick bits of assistance to everyone in sight—and is consolidated in time chunks instead of sprinkled throughout the day or the week. When you give to just a few people, and erratically, selflessness is a well-intentioned but ineffectual drain on your time. But with broad and efficiently concentrated giving, you reach (if you’ll forgive another social science buzzphrase) a tipping point at which your reputation as a giver and your accumulation of grateful pals grows to the point that positive effects ensue.

A workplace full of givers is, in Grant’s view, an ideal scenario. An environment where people are motivated to help will actually enhance their own effectiveness. When I asked Grant how managers might encourage a culture of giving, he told me the first step is, not surprisingly, careful hiring.

“Most people think you should try to hire givers,” says Grant, “but the data suggests that if you want a culture of givers the most important thing is in fact to screen out takers. The negative impact of a taker is double or triple the positive impact of a giver. With one taker on a team, you begin to notice that paranoia spreads and people hold back out of fear that they’ll be exploited.” And how do you spot a taker? “The main sign that someone’s a taker is kissing up and kicking down. Takers are good fakers when they’re dealing with powerful people, but it’s a lot of work to pretend to care about everyone so, selectively, they’ll let their guard down. Another telltale sign is taking a lot of credit for successes, and blaming other people for failures. Givers are more likely to take responsibility for failures.”

Once you’ve got the right people in place, the next step is to design the right incentives. Grant suggests rewards that are substantial enough to recognize givers’ efforts but not so large that they encourage takers to game the system. Also, consider making the incentives collective. “Most organizations reward individual achievements,” says Grant, “which favors takers.” Other ideas: Make sure people aren’t afraid to ask for help—not in a taking way, but in a manner that lets givers know where their help is most needed. Also, managers can designate a “utility player” (perhaps a role that rotates between different people) whose sole mandate on a given day is to help out colleagues.

To be sure, under closer examination, there’s some delicate semantic nuance involved if we are to accept Grant’s concept of givers and takers. Grant is telling us we should give in large part because we will benefit. The subtitle of his book is “Why helping others drives our success.” Which, if my calculations are right, would seem to transform us all into matchers in the end. We’re expecting returns. Grant’s analysis also suggests that givers are only successful when they consider their own needs, while they tend to fail when they are truly selfless and without guile. Perhaps his tripartite taxonomy would be better labeled “takers, matchers, and slightly savvier matchers”?

Still, one imagines workplace culture might improve if we were all convinced to value generosity. And Grant’s other research efforts often delve further into the value of allowing ourselves to be less aggro in our professional lives. He argues, for example, that introverted managers can be more successful than extroverts. Extroverts do better with passive employees who need lots of direction. But introverts—who ask more questions and don’t try to steal the spotlight—excel at bringing out the very best in their self-motivated employees, who are ultimately the most valuable. Introverts might also, counterintuitively, make better public speakers. “Many of the most viewed TED Talks are given by self-identified introverts,” Grant told me. “I would like to study that. It might be about better preparation, or there might be some degree of authenticity advantage.”

Ultimately, Grant’s research suggests that our ideas about workplace politics might need some updating. Classic alpha-dog strategies aren’t necessarily a winning play. Don’t be afraid to retract your claws, un-bare your teeth, and do what’s best for the pack.