Pop culture teaches us that getting ahead requires stepping over or directly on those that might stand in your way or slow you down. It's a ruthless, dog-eat-dog rat race or whatever mixed animal metaphor you might prefer. 

An international team of researchers from Stockholm University, the Institute for Futures Studies and the University of South Carolina analyzed data gathered from both Americans and Europeans and found that unselfish people tend to have both higher salaries and more children.

"And we also find this result over time - the people who are most generous at one point in time have the largest salary increases when researchers revisit them later in time," says co-author Kimmo Eriksson from Stockholm University.

The study defines unselfishness as "the desire to help others because you care about their welfare," including having the attitude that helping others is important and taking action to give or help others.

Previous research and countless TV, film, music and literary narratives have suggested that it's actually selfish people who get more money. Wasn't it the remarkably alliterative Gordon Gecko who taught us that "greed is good?"

"In a separate study, we examined the expectations of ordinary people to see if their expectations aligned with our data. The results of this study showed that people generally have the correct expectation that selfish people have fewer children, but erroneously believe that selfish people will make more money. It is nice to see that generosity so often pays off in the long run," says co-author Pontus Strimling, a researcher at the Institute for Futures Studies.

Previous studies have also heralded the other benefits of being unselfish, such as better relationships and more happiness. 

But what is the connection between being selfless and earning a better salary? The new research doesn't directly answer this key question, but the researchers say it could be that being generous improves social relationships that in turn improve earning potential.

"Future research will have to delve deeper into the reasons why generous people earn more, and look at whether the link between unselfishness, higher salaries and more children also exists in other parts of the world. And it is of course debatable how unselfish it really is to have more children," says co-author Brent Simpson of University of South Carolina.

Maybe, but it's probably not advisable to have that debate with family over the holidays.