A teen suicide in southern Minnesota last week that the child's parents and bullying experts are blaming in part on bullying is bringing greater attention to a specific type of social bullying.
But it's not the physical torment that's often labeled as bullying. Instead, it is a form of psychological harassment among people who know each other called relational aggression.
Experts say it's much more common than physical bullying
The parents of 13-year old Rachel Ehmke say their daughter was targeted by a group of girls in her Kasson-Mantorville middle school last fall.
Rick Ehmke, of Mantorville, Minn., said the girls called Rachel names, spread rumors about her and defaced her books and locker.
Ehmke said the harassment continued throughout the year and contributed to Rachel's suicide a little over a week ago.
Experts say that kind of behavior would be a clear case of relational aggression.
"Kids who are victims of relational aggression become more lonely, depressed and anxious over time," said Nicki Crick, a professor of child psychology at the University of Minnesota.
Crick, who has studied relational aggression and its effect on young people, said it's possible such behavior was one of the factors that pushed Rachel Ehmke to take her life.
"Bullying by relational aggression or any kind of bullying can be a huge stressor that possibly can contribute to an event like that," Crick said.
Relational aggression covers many different kinds of bullying behavior, from spreading vicious rumors, to excluding someone from a group. Even giving someone the "silent treatment" is considered a form of social bullying.
Crick said it's more common among girls.
"Girls more so than boys care very much about establishing close relationships with other people," Crick said. "So relational aggression is an effective way of hurting, something that girls care about because they care so much about close, intimate friendships and relationships."
Experts say relational aggression happens much more often than the physical harassment often considered bullying, like the big kid beating up the smaller kid over lunch money.
By its very nature relational aggression can seem confusing and cruel, said Walter Roberts Jr., a professor of counseling at Minnesota State University in Mankato.
"When peers turn against one another, when the people you're supposed to be able to count on turn against you, that's a very hard thing to deal with," he said.
Kayley Spencer, a 15-year-old from Watertown, Minn., said classmates she considered friends picked on her constantly last year, when she was in the eighth grade.
"From what I was wearing, to my interests, to how I wore my hair that day," she said. "At first I would just say to myself, 'It's just one comment, you can handle it.' But I'd go home and start thinking about it and all the comments would accumulate and really build up and make a bigger effect."
Another aspect of relational aggression that can wear students down is how it seems to thrive in online spaces, like Facebook.
"When a student comes home they're no longer escaping the bullying," said Julie Hertzog, director of national bullying prevention for the Minnesota-based PACER Center. "A lot of times we'll hear about kids who are in a bullying situation who will be checking their social media all night long, so they're kind of obsessing about it."
Hertzog said relational aggression is easy to hide, both by bullies and the targets of bullying. She said the key to stopping bullying is to talk about it.
That's what Kayley Spencer discovered.
"My advice is to tell someone as soon as possible," she said. "That was my problem. I didn't tell anyone. I kept it to myself and it made it way worse."
Kayley said she is doing fine now as a freshman in high school.
Bullying experts say supporting victims when they come forward is critical. They also say punishing the aggressors, or in some way letting them know their behavior won't be tolerated, is even more important.