What would constitute a clinical control group with problematic levels of anger?

I am completing coursework on the study of anger in individuals with persecutory delusions and it has been suggested that I use a clinical control group with problematic levels of anger, how would I select this group of individuals?|||They could be measured using: http://www4.semo.edu/snell/scales/CAS.HT鈥?/a>|||Look at whether or not they are using punishment as a social motivator.