[Personality and life style].

The association between personality and various living habits was investigated in a cross-sectional study of 2,892 residents of a town in Saitama prefecture. Living habits including dietary, smoking & drinking habits, degree of mental stress and personality type were surveyed from 1986 to 1988 by use of a self-administered questionnaire together with biochemical & immunological examination of peripheral blood samples. Personality in this study was classified into two types: extraversion which is characterized by persons who are active and emotionally stable; introversion characterized by suppression on emotional and behavioral expression. Our results can be summarized as follows. 1) The introversion type of persons showed higher susceptibility to mental stress, less regularity in meal time, lower intake frequency of animal protein foods (meat, fish and eggs), green & yellow vegetables, fruits, and cruciferous vegetables with statistical significance of p less than 0.05, as compared to the extraversion type. 2) The above association was further examined in each of the sexes and age groups. The association of the introversion type of personality with increased stress and low intake of high animal protein foods was observed for both sexes and all age groups; the association with low intake of eggs and irregularity of meal time was observed for both sexes for groups under 60 years old; that with low intake of fish & shellfish, fruits, cruciferous vegetables and green & yellow vegetables was observed more clearly among males than females. These results indicate that introversion type of personality appears to be associated with a life style that increases the risk for adult diseases such as cancer, ischemic heart disease etc.