Weise, the two Columbine killers and Kinkel had a "cynically shy score" of 10 (on a scale of 10). Rouse, Woodham and Loukaitis had scores of 8, and Carneal had a score of 6, the researchers said.
Cynically shy people tend to be male and want to relate to other people but just don't know how. As a result, they get rejected, and feelings of hurt gradually turn into intense rage, the study authors said.
This seems to be an extreme version of the frustrations other shy people often face.
"We often misinterpret why people are shy," Henderson said. "If you walk by somebody and avoid eye contact, you interpret that as they don't want to interact, but I think often it's completely the opposite. They really do want to interact and don't know how.
"It's important for parents and teachers to start at a young age, before the person is walking down the high school corridor ready to shoot, not to interpret their behavior as not wanting to interact," Henderson continued. "If we flip our interpretations, people may respond differently. As a field, we need to understand prospectively what's happening, so we can start identifying kids at a very young age, what would drive a shy kid into this pattern. We don't want the message to be 'shyness will lead to shooting.' "
To learn more, visit the Center for the Prevention of School Violence.
SOURCES: Bernardo J. Carducci, Ph.D., director, Shyness Research Institute, Indiana University Southeast, New Albany; Jane Ripperger-Suhler, M.D., assistant professor of psychiatry and behavioral science, Texas A&M Health Science Center College of Medicine, and psychiatrist, Scott & White Mental Health Center, Temple; Heather Henderson, Ph.D., assistant professor of psychology, University of Miami; Aug. 18, 20