Cross-cultural (Japan-Slovakia) comparison of some aspects of sleeping patterns and anxiety

We compared differences in sleeping habits and anxiety as a trait (real duration of sleep, duration of necessary sleep, time of going to bed and regularity of sleeping habits) in 593 Japanese and 225 Slovak children aged 12-13 yrs. The results point to a statistically significant negative relationship between anxiety and the real duration of sleep in children from the entire combined sample (n = 818). Children who go to bed late have a significantly higher score in anxiety. Differences in the duration of real sleep and the duration of necessary sleep (to feel refreshed) are significant - they are significantly higher in Japanese children (boys and girls) than in Slovak children. In Japanese children this difference can reach 2.17 hrs., in the Slovak children it is 1.35 hrs. Furthermore, we found significant cross-cultural differences in the time of going to bed (Japanese children go to bed later) and real duration of sleep (Japanese children sleep less). The results are discussed with respect to the harmonization of biological and social rhythms and effects on anxiety and school success.