Tom, research psychologists and research sociologists would be found at universities as faculty members. They may have lower level researchers in their groups who are also knowledgeable (and perhaps more accessible). The person you described who lost control of group therapy sounds like a (not very good) clinical psychologist who is in practice treating patients. This is not the same as non-clinical research psychologists, who don't treat patients. They teach and do research. I'm not sure if they can answer your questions but you wanted someone different from a practitioner. Another idea is to read the relevant research in psychology and sociology in a university library. Good luck.