Activity Monitoring of the Inhabitants in Tauwema,a Traditional Melanesian Village: Rest/Activity Behaviour of Trobriand Islanders (Papua New Guinea)

The inhabitants of Tauwema village represent a traditionally living society. Altogether, 39 inhabitants belonging to seven families were included in this study. Families or people living in one household were preferentially chosen for monitoring particularly the effects of social zeitgebers and synchronization within families. They were observed continuously for 7 consecutive days using microelectronic actometers that register locomotor activity with a sampling period of 2 minutes and a resolution of 7 bit. The activity data obtained showed that in young infants circadian patterns develop out of ultradian components dominating in the first months of life. The rhythmicity of the adults was well-related to the natural light-dark cycle, combined with a strong social component which is reflected in a comparatively small intra- and inter-individual variability in the time of the end of the main sleep span in the morning, while the variability in the beginning of the main sleep period in the evening is much greater. The mean sleep duration of the younger infants (up to 11 months; n =4) varied between 9 and 12 h per day and that of the adults (n = 23) between 7 and 10 h. Gender-specific differences occurred in married couples with wives having a longer sleep duration in 7 out of 9 cases.