If you don't have something nice to say ... well, go ahead and say it anyway. You may actually be doing something good for your health as well as humanity.

UC Berkeley psychologists have found that gossiping - specifically spreading information about a person who has behaved badly - can play a critical role in maintaining social order, preventing exploitation and lowering stress.

"We tend to think of gossip as a bad thing and it gets a bad reputation, but if you were to remove it, that would be at the cost of social order," said Robb Willer, UC Berkeley professor of psychology and sociology and co-author of the study, which was published in this month's online edition of the Journal of Personality and Social Psychology.

To be clear, the researchers didn't study the rumormongering type of gossip spread about such things as whether Kim Kardashian's marriage was a sham from the get-go or if the Duchess of Cambridge is really pregnant with an extraterrestrial baby.

The researchers did focus on the act of spreading negative information about people who aren't participating in the conversation, clearly the hallmark of all self-respecting gossip. But they refined it to what they called "prosocial" gossip - dare we say "good"? - which has the function of warning people about the untrustworthy or dishonest behavior of others.

"Much of what we call gossip is driven by a sincere desire to help others," Willer explained. "Gossip can make you feel better. You might even say it's therapeutic."

He added that he and the other researchers required that the information being spread be reliable.

The cheats

In a series of experiments, researchers used various games to create situations in which observers witnessed others cheating. They had the observers' heart rates measured and also gave them the opportunity to warn others in the form of "gossip notes." They found heart rates increased in those who had seen others cheating. Taking the opportunity to "gossip" by passing warning notes to others helped calm the rise in heart rates of the witnesses and made them feel better, the researchers noted.

To raise the stakes, one version of the experiment required people to sacrifice money if they wanted to send a gossip note. The majority - 76 percent- were willing to take at least some financial hit to send a note.

The largest experiment involved 300 participants from all around the country recruited on Craigslist to play an online economic trust game. The players had filled out questionnaires that determined their level of altruism or selfishness.

After being told that observers had the ability to pass gossip notes alerting others about those not playing fairly, virtually all the players acted more generously. The threat of being the subject of negative gossip had the greatest influence on those who scored low on altruism.

"With gossip present, it was effective in deterring people who acted more selfishly to behave in a more trustworthy way," Willer said. "This is evidence for our ideas that gossip deters selfishly motivated people from acting on those concerns."

Outsiders' views

Dr. Laura Davies, a child and adolescent psychiatrist at California Pacific Medical Center in San Francisco, said the UC Berkeley study focused on a specific kind of gossip that many people don't consider gossip.

Davies, who was not involved in the study, acknowledged that conducting a real-life gossip experiment would be challenging, but she didn't think the scenarios the researchers used fairly represented gossip and the complex dynamics between "selfish" and "altruistic" people.

"This study is incredibly limited and purports to answer a lot more than it actually does and should be taken with a huge grain of salt," she said.

On the other hand, Dr. Mason Turner, chief of psychiatry at Kaiser San Francisco, agreed with the research that sharing information about someone can have a cathartic effect.

"If you're holding on to some negative info about someone, sharing that with someone is sharing that burden," said Turner, who also had no connection to the study. "But you have to ask yourself: Are you rumormongering or trying to discredit somebody, or are you sharing information that's tough to hold on to?"

E-mail Victoria Colliver at vcolliver@sfchronicle.com.