Abstract
The 'grandmother hypothesis' is connected with a distant evolutionary event of the emergence of menopause in human females, and can be put to the test by (historical) demographic data for European society of the Early Modern Age and the Modern Age. Comparisons of case studies and micro-analytic probes into historical demography and cultural history of the 17th-19th c. allow us to draw certain conclusions: where the 'grandmother effect' (i.e. shorter inter-birth intervals in daughters or daughters-in-law alongside with a lower rate of infant and child mortality of grandchildren, in other words, fitter grandchildren) can be proven from a statistical point of view, in most cases, the effect is significantly weaker than the effect of other factors that influence infant and child mortality rates.
Grandmothers participating in the care of their grandchildren probably were not a 'cultural pattern' (reflected as such by its actors), in any case, not to the degree to which a 'cultural pattern' was reflected in a regionally specific structuration of households or the use of midwives' services. At least, in European populations of the 17th-19th c., we can find other institutions that seem to have had a stronger effect on infant and child mortality rates than grandmothers taking care of their grandchildren.
During this period, the grandmother effect was geographically diffused and, in some cases at least, linked to particular social groups or segments of society (in a Czech sample, for instance, the effect was linked to lower social classes). If the grandmother effect that increases the fitness of grandchildren is more pronounced with maternal grandmothers (which is yet to be generally proven), we must ask why cultural evolution has 'chosen' the adaptively less favourable option of patrilinear structuration of family households.
An example of such structuration can be found in a consistent patrilocality of marriages and patrilineality of family structuration in classical antiquity, which in the European environment has survived southeast of the so-called Hajnal Line until recently. Research in demography and cultural history of the 17th-19th c.
European society seems to strongly support the following claim, which from the perspective of evolutionary anthropology or evolutionary biology is merely a hypothetical supposition: The 'grandmother effect' may have been the cause of the menopause as an evolutionary adaptation. Nonetheless, while this effect has been present in the human population since ancient times (prehistory or antiquity), it was merely one of many mutually complementary, alternative, and more or less adaptive (i.e. fitness-increasing) forms of infant and child care.