Illumination | Fall 2007

"It was really bringing them down," Rose says. "It just really leaped out at me, how this kind of conversation can lead to bigger problems."

From observations like these, Rose developed her novel concept of "co-rumination," where two close same-sex friends hash out their problems, analyze them in detail and hash them out again. Co-rumination offers fertile ground for negative feelings and endless speculation.

'There is an unwritten code of conduct for girls that deems it inconsiderate, or even rude, for a girl to ignore a friend's problems or concerns.'

"You really see this intense level of dissection in their conversation," Rose says. "What the tone of a voice might mean, what are all the explanations for not being invited to a party."

Rose, 36, has taken an intense interest in the playground who's who for as far back as she can remember. "It feels like I've always been interested in friendship," she says. Even as a teenager growing up near Dayton, Ohio, she paid close attention to who was friends with whom. That interest in friendships turned academic when she majored in psychology at Ohio State University, and then at the University of Illinois, Urbana-Champaign, where she received her doctorate in 1999.

Her mentor at Illinois was Steven Asher, now at Duke University, a leading researcher on peer relationships. She built on his work by pursuing her interest in gender differences in friendships. It was during that time that Rose first noticed the different patterns of playground activity that led her to the idea of co-rumination. Rose joined the Missouri faculty right after she graduated and began working on co-rumination soon after, collecting vast amounts of data on public school students in the state.

For her first study, published five years ago in the journal Child Development, Rose had about 600 students in third, fifth, seventh and ninth grade classes fill out a series of questionnaires to assess the quality of their friendships, their levels of anxiety and depression and the extent of their co-rumination. Only same-sex friendships were considered because they are far more common at these ages and more likely to lead to conversations about personal problems.

The co-rumination questionnaire that Rose created posed queries such as, "When we talk about a problem that one of us has, we usually talk about that problem every day even if nothing new has happened." The study was a massive undertaking that required the help of several graduate students and about 30 undergraduates to eventually complete.

Rose found that girls co-ruminated and confided in their girlfriends significantly more than boys confided in other boys. Girls reported closer, higher quality friendships. But girls also reported more depression and anxiety than boys. And both the high-quality friendships and the emotional distress correlated closely with higher levels of co-rumination.

The study, however, left some important questions unanswered. Rose's data wasn't sufficient for her to determine whether co-rumination was contributing to depression and anxiety, or was something that depressed and anxious children were just more likely to do. To answer that question, she needed to follow a group of children over time. The results of that study, published this year in Developmental Psychology, set off the media whirl over co-rumination.

Published by the Office of Research.