Perhaps you should give your friend that last piece of chocolate, because according to new research from evolutionary biologists at Michigan State University, selfishness is a trait not favored evolutionarily in humans, and such people may eventually die out, the Daily Mail reports.

Researchers used high-powered computing to run hundreds of thousands 'games' to determine whether selfishness or selflessness would win out in the end, and they yielded some fascinating results.

"We found evolution will punish you if you're selfish and mean," said Christoph Adami, professor of microbiology and molecular genetics at the university, who led the study. "For a short time, and against a specific set of opponents some selfish organisms may come out ahead. But selfishness isn't evolutionarily sustainable."

However, their discovery conflicts with the widely held theory "Zero Determinant," in which selfishness keeps evolution ticking over.

According to Professor Adami, it is important for humans to be able to communicate and cooperate properly so the "winning" is always beneficial. For instance, the researchers used the prisoner's dilemma game in their study of selfishness.

In the game, two people who are caught by police go to jail and are offered a deal: rat out your friend and go free while they spend six months in jail. If both prisoners rat each other out, they both get three months in jail, while if they both stay silent, they both get one month in jail for a lesser offence.

If the two prisoners get a chance to talk to each other during the game, they are more likely to establish trust and cooperate through an alliance, both agreeing to spend one month in jail and mutually remain silent. But if they're not given a chance to speak to each other, their best strategy is to rat each other out because it guarantees they'll avoid a longer jail term.

The game poses the simple question: do I act selfishly or cooperate?

Though it may be tempting to freeload and "cheat," cooperating benefits both individuals. Thus, the zero determinant (selfish) way only works if the player knows who their cooperative opponent is and beats them by exploiting their weaknesses. However, once all selfish players in a game eliminate all of the cooperative players, they are no longer be able to exploit anyone else and no one wins the game.

Thus, Adami argues, cooperation is central to the strategy of winning, as it tends to bring long-term success as opposed to the short-term goal of beating out all of the weak players.

"Communication is critical for cooperation - we think communication is the reason cooperation occurs," he told the Daily Mail.

This same set of principles may apply to all organisms, from single-cell organisms to humans, including tribes, nations and families. Adami said he hopes to test his team's cooperation-based experiments on yeast cells in the near future.

The study was published in the journal Nature Communications.

Click here to read more about the prisoner's dilemma and how it relates to zero determinant strategies.

*This article has been updated with a change.