The Hadza use no birth control and choose their own spouses; this makes them what the researchers call a "natural fertility population" where hypotheses about human reproductive success can be tested.
Popline Index to worldwide information about migration, contraceptive methods, demography, family planning, maternal and child health, human fertility, population law and policy, sexually transmitted diseases, vital statistics, etc. Covers journal articles, books, government publications, and technical reports.
Index to worldwide information about migration, contraceptive methods, demography, family planning, maternal and child health, human fertility, population law and policy, sexually transmitted diseases, vital statistics, etc. Covers journal articles, books, government publications, and technical reports.
The book reviews also the situation of the developed countries and their specific challenges – sub-replacement fertility, population aging, and immigration – and examines the effectiveness of population policies.
Among the Dogon, a natural fertility population in Mali, Strassmann has found that women have about 100 periods over their lifetime.
Low fertility, population mobility, aging, and the improvement of housing conditions were among the most significant factors that brought about changes to the family and the household in China.
Furthermore, we demonstrate that while variation in ovarian cycle length appears to be ubiquitous among animals with these cycles, this does not rule out the possibility of synchrony and asynchrony occurring in natural fertility populations.
Further research on this phenomenon in hamadryas and other species is justified, therefore, albeit with a focus on natural fertility populations and employing null-model techniques similar to that used here.
We outline why the absence of synchrony and asynchrony and variation in cycle length in this and other studies are explicable when one considers (1) the brief ovarian cycle bouts typical of natural fertility populations and (2) the type of synchrony or asynchrony measures that were employed.
Those bounds span the range of fertility levels and patterns in most below replacement fertility populations.
There are a few such "natural fertility" populations even today, and women in these societies spend most of their reproductive life either pregnant or breastfeeding.
