The so-called 'pit-dwellings' of the Jömon people, prehistoric food gatherers in Japan, have been actively studied from the typological-chronological point of view but the function of the dwellings as means to social life still remains largely unknown. Any group of the pit-dwellings of the same age or period found existing side by side in a locality is called a 'settlement'. However, no attention has been drawn to the stability of habitation and, accordingly, there has been no systematic pursuit of the subject.
In traditional archaeological approaches tools, structures, and other features are classified into various categories each being described separately and compared independently with the comparable categories of other sites. But the study of such a subject as the stability of habitation need a functional-conjunctive approach based on various kinds of data which usually have been handled separately. A comparative study of northern peoples proves that the stability of habitation is functionally and ecologically related with the following features: manufacture and use of potteries; weight of stone implements and stone structures, and time required for the manufacture; presence of collective burials or graveyards; dimension (diameter and depth below the floor) of the posts or postholes of shelters; evidence of rebuilding or reforming of shelters. The analysis of the Jomon pit-dwellings from the above point of view resulted in a conclusion that the dwellings were permanent ones in the sense that those were occupied recurrently or continuously year after year. Those may have been seasonal (possibly winter) dwellings but we still do not have definite evidence to prove it.
The stability of habitation raises some important problems on population history and ethnohistory. Fixed or permanent habitation implies more stabilized social relations than in unsettled nomadic gatherers and cultural elaboration adjusted to the settled mode of life. From this point of view it may be assumed that the Jomon people's society was provided with the receptivity to farming cultures or culture-complexes. What were the effects of the receptivity in the process of change from the gathering-oriented culture of the Jomon stage to the rice-farming culture of the Yayoi stage? The nature of the Yayoi culture and the formation of the Yayoi people should be studied and re-examined from the view point of the Jomon people's receptivity to agriculture. Another effect of the stability of habitation has biological implications. Social life with permanent habitation may have changed selective pressure. The possibilities for the aged and the sick or weak to live longer or survive may have been greater in these settled gatherers than in unsettled nomadic gatherers. WASHBURN & DEVORE'S concept of 'home base' may be extended even to the study of the history of primitive or prehistoric local populations and their demography. It is hoped that students of population history and palaeodemography will positively take into consideration the stability of habitation as a possible factor.