" Ryan and Frederick (1997) showed that in a population suffering from debilitating pain, pain level per se did not detract from vitality. Instead, pain fright was negatively associated with vitality, as was attending treatment for external as opposed to internal reasons. Some of the factors that may influence one’s sense of vitality and contribute to its resilience are one’s feelings of personal causation, optimism, and perceptions of social support. "

― , Character Strengths and Virtues: A Handbook and Classification