Abstract

The possible relationship between sleep habits and personality traits was investigated in 565 college students. Four aspects of sleep patterns(length, circardian rhythm, regularity, refreshed feeling at the time of awakening) were evaluated on the basis of sleep questionnaire. In each aspect, subjects were categorized into three groups : two extreme groups of those who belong to upper or lower ends of the distribution(long vs. short, morning vs. evening, regular vs. irregular, refreshing vs. nonrefreshing) and an intermediate group of those who do not belong to either group. To compare personality characteristics between groups, the Korean version of MMPI (1989) was administered to all subjects and the results were interpreted according to methods of Kunce & Anderson (1976, 1984). The main findings are as follows. 1. In sleep lengths, the intermediate group was better able at organization and imagination than the short and long sleep groups. The short sleep group showed greater zest than the long sleep group. 2. From the view point of circadian rhythms, the evening type showed higher perception of stress than the morning type but lower than the intermediate type. The ability for conservation and evaluation was higher in the evening type than in the morning type while assertiveness was greater in the intermediate type than in the morning type. 3. The irregular sleepers showed higher ability of evaluation and imagination than the regular sleepers. 4. The unrefreshed group showed a greater ability to be conservative than both the refreshed and the intermediate groups. Also the unrefreshed group showed greater ability at evaluation, expression, organization, and imagination than the refreshed group. The present findings support the assumption that a relationship exists between specific aspects of sleep patterns and personality traits in normal young adults. However, the limitations in generalizing these findings should be considered and there is need for further study.