After many years of distrust and disuse, the concept of a personality trait is once more proving useful in many types of studies. New tools of analysis have made it possible to define and refine the idea of what personality traits actually are, and to demonstrate the universality of certain kinds of individual differences. The term personality captures the collective and dynamic organization of all the psychophysical systems that determine the adjustment of the person to his/her environment (Svrakic and Cloninger, 2005). Temperament is defined more restrictively as the body’s biases as it modulates behavioral responses to and styles of coping with prescriptive physical stimuli, such as danger, stressors, or various types of reward. Personality and temperament are of importance to health professionals because they can underlie certain psychiatric illness (Hirschfeld, 1999). In addition, certain aspects of personality have been associated with increased risk for coronary artery disease and the contraction of human immunodeficiency virus (HIV), psoriasis, ulcerative colitis, and many other diseases that have been described as psychosomatic (McCown, 1993; Tyrer, 1995). Dimensions of temperament may also predispose people to health risk behaviors such as tobacco use.

A principal reason for the scientific re-birth of personality traits is the use of factor analysis to define and validate them. The “Big Five” model, the one whose use is most widespread and accepted, is based on factor analyses of self-reported descriptions of social and emotional behavior. The five personality domains are: Neuroticism (N, negative affectivity), Extraversion (E versus Introversion), Openness to experience (O), Agreeableness, and Conscientiousness. This model is based on a robust factor structure that has been validated in a variety of populations and cultures using the NEO-Personality Inventory (NEO-PI), a personality test designed to assess normal adult personality (McCrae and Costa, 2002). The population samples were drawn from the United States, Germany, Portugal, Israel, China, Korea, and Japan, and included people from ages 18 to 105 (McCrae et al., 1999; Labouvie-Vief et al., 2000).

Personality traits are consistent and are associated with behavioral trends, coping strategies, and health behaviors. This makes it possible to use them to predict health and life outcomes (Whitbourne, 1987; Bosworth et al., 1999; Caspi and Roberts, 1999), depending on the strength of certain traits. To some extent, Alzheimer’s disease (Siegler et al., 1994) and CVD