Seems that over the years psychologist have shown that good/elite distance runners tend to be less depressed, show lower anger, score lower on neuroticism and show higher vigor and more emotional stability. Seems to me that this is the opposite of the average LetsRun poster. This leads me to believe that most people on here are failed runners who lacked the mental fortitude and now like to snipe from the sidelines.
Selected References:
Raglin, J.S. (2001) Psychological factors in sports performance: the mental health model revisted. Sports Med. 31:875-90.
Morgan, W.P., Pollock, M. (1977) Psychologic characterization of the elite distance runners. Ann NY Acad Sci, 301: 382-403.
Morgan,W.P., Costill, D.L. (1996) Selected Psychological Characteristics and Health Behaviors of Aging Marathon Runners: A Longitudinal Study. Int. J. Sports Med, 17: 305-13.