The best way to maintain the psychological health of a group will be to have everybody fully occupied with productive tasks. Organizational and leadership skills will be vitally important. There will still be problems. Leadership will hopefully respond to the challenges when they arise. The purpose of a posse in the old days was to take extreme action with the support and presence of significant members of the community, in sufficient numbers to be over powering. In your above scenario, I'm afraid we need a posse and an oak tree.
Offered by Jack.
If you choose to fight as a way of dealing with others make sure that everyone in your group agrees with you and the consequences that it brings. We all may face events that will call for a drastic measures. If you witness a group of people that will choose to rape and murder just for fun of it, you may have no other choice to stop them. Discuss it with your friends and family before it happens, so you all will know the answer.
Offered by Chris.