Bullying in the medical profession is common, particularly of student or trainee physicians. It is thought that this is at least in part an outcome of conservative traditional hierarchical structures and teaching methods in the medical profession which may result in a bullying cycle. The rampant problem of medical student mistreatment and bullying was systematically studied and reported in a 1990 JAMA study by pediatrician Henry K. Silver which found that 46.4 percent of students at one medical school had been abused at some point during medical school; by the time they were seniors, that number was 80.6 percent.