The Influence of Type A Characteristics on Living Habits

The present studies investigated the relationship between Type A characteristics and living habits centering on sleeping habits of female college students. In Study 1, 342 female students completed KG's Daily Life Questionnaire to measure their Type A characteristics and Tokyo Metropolitan Institute for Neurosciences Living Habits Inventory to measure their living habits concerning sleeping, eating, exercise and others. Results showed that Type A students (defined as the students above the median of Type A scores) had stronger “evening” characteristics, more variable bedtimes, higher level of post-sleep negative emotion, more dreams and nightmares, more skippings of breakfast and dinner, more frequent late-night meal taking, higher alcohol intake, and more frequent all-night activities than did Type B students. These results altogether showed unhealthy habits in Type A individuals.<br>Study 2 investigated whether these characteristics of living habits in Type A individuals depend on conditions, by comparing living habits during usual working days with those during a long summer vacation. 247 female college students completed Type A questionnaires and Living Habits Inventories before a summer vacation began, and answered the same Living Habits Inventories just after their vacation was over. In this study, the Type A questionnaire was the same as in Study 1, but the living habits inventory was the short version made of the original inventory used in Study 1. Results showed that in addition to the results obtained in Study 1, Type A students had later bedtimes, more variable waking times and sleep duration, longer sleep duration, more satisfaction with sleep duration, more trouble falling asleep, and more frequent lunch-skipping than did Type B students. Moreover, significant interactions between groups (Type A or B) and periods (usual working days or a vacation) were found in three items: time falling asleep after going to bed, alcohol intake, and late-night meal taking. These interactions indicated that Type A students showed the same unhealthy habits independent of the periods, whereas Type B students showed more unhealthy habits during their vacation than during their usual working days, suggesting that Type B individuals changed their living habits according to lifestyle conditions.<br>Those two studies clearly show that worse living habits in Japanese Type A individuals range over not only sleeping habits but also eating habits. Moreover, judging from the results that unhealthiness of living habits in Type A individuals is valid also during long vacations, this persistent disturbance of habits might be seen as a mediative factor in Type A characteristics and mental or physical disorders this group exhibits.