Kelby Johnson attends a panel discussion after a screening of the documentary "Bully" at MPAA on March 15, 2012 in Washington, DC. (Photo by Kris Connor/Getty Images for The Weinstein Company) Kelby Johnson attends a panel discussion after a screening of the documentary “Bully” on March 15, 2012 in Washington. (Photo by Kris Connor/Getty Images for The Weinstein Company)

Once considered a rite of passage, bullying has become a cultural touchstone. The much-discussed topic is the subject of books, a documentary film, and social movements.

By now, we know that bullying is bad for kids on the receiving end of taunts. But how does bullying affect the bullies?

A new study, published Monday in the Proceedings of the National Academy of Sciences, shows bullies may actually reap long-term health benefits from elevating their own social status at the expense of others.

“Our study found that a child’s role in bullying may serve as either a risk or a protective factor for adult low-grade inflammation,” William E. Copeland, associate professor of psychiatry and behavioral sciences at Duke University School of Medicine and the study’s lead author, said in a statement.

Chronic low-grade inflammation — measured by checking certain protein levels in blood — is tied to an array of health problems, including cardiovascular disease and metabolic disease. Other problems, like poor nutrition and low socioeconomic status, can also lead to chronic low-grade inflammation, but the study controlled for those factors to isolate the effects of bullying.

The researchers followed 1,420 individuals over 20 years, interviewing participants about their experiences with bullying and conducting blood tests to measure chronic low-grade inflammation.

The researchers found that the physical health effects of childhood bullying persisted well into adulthood. Bullied children suffered more from chronic low-grade inflammation in adulthood while bullies suffered less. Adult bullies had lower levels of chronic low-grade inflammation than peers who weren’t part of bullying at all, either as victims or aggressors.

Bullying has long been considered a rite of passage. But the findings suggest bullying is akin to serious childhood traumas such as child abuse, the researchers said.

Another study published last week examined a new potential threat to self-esteem that affects people of all ages: social media.

Researchers from the University of Queensland in Australia looked at how social Web sites such as Facebook affect self-worth and social belonging. The study, “Threats to belonging on Facebook: lurking and ostracism,” published by Taylor and Francis Group, an academic book publishing house, found that being a wallflower online led to lower self-esteem.

The researchers performed two tests. In the first, they compared users who actively post on Facebook to those who don’t and found that passive participation had a negative effect on well-being. For the second test, the researchers gave participants access to anonymous Facebook accounts and told them to post and comment as they normally would. Half the group wasn’t told their posts would be ignored, meaning no comments or other interaction from other users online. The ignored group reported lower self-esteem after the study.

Related content:
STORY: A new way to battle bullying: Make a ‘Glee’-style music video