What Causes School Shootings?

It is unfortunate that no one really knows what causes school shooting. What psychologists seem to thing is the primary cause of school shootings is the abuse and alienation that a student puts up with from other groups of students that are more popular than they are. The student gets angry and resentful, and to a point snaps and goes on a tangent of sorts because they just do not know or understand how to handle these deep feelings.