Psychologically healthy people want power and authority over their futures. When the people perceive control in their lives, they feel optimistic and secure. Psychologists began to research resilience in earnest when Norman Garmezy arrived at the University of Minnesota in 1961. The commitment disposition involves a tendency to involve oneself in—rather than experience alienation from—whatever one encounters. The disposition to embrace challenges comes from the belief that change, rather than stability, is normal. People with PTSD have intense, disturbing thoughts and feelings related to their experience that last long after the traumatic event has ended. The ability to find meaning in difficult times forms the foundation of resilience. Anthropologist Gregory Bateson asserted that to communicate and to establish meaning within oneself and between individuals forms the core of their humanness. Mental competitions often involved bets, involving the use of collateral one would not normally use. Seldom do people raise their hands and volunteer to suffer adversity.