Social Psychological Processes Linking Personality to Physical Health: A Multilevel Analysis With Emphasis on Hostility and Optimism

P ersonality has long been suspected as a factor in uencing physical health outcomes (Alexander, 1950). One of the earliest of such accounts had its roots in the theorizing of Hippocrates around 400 bc. Hippocrates is widely regarded as the father of modern medicine. He proposed that the body was composed of four primary humors, and it was the balance of these that maintained health. This thinking dominated early medical thinking, but it was Galen, around

160 ad,, who further elaborated on the “temperaments” potentially associated with these four humors. These humors were thought to be associated with traits such as irritability, sadness, enthusiasm, and apathy. This work formed one of the earliest attempts to explain disease based on personality processes that might be evident to the “observant physician.”