This article uses the mean age at menarche of women in China as an indicator of changes in the standard of living during the 20th century. It discusses the difficulties of using this indicator. It finds that the mean age of menarche stagnated at 16 to 17 years for women born during the period between the 1880s and 1930s. The age at menarche decreased in some urban areas, indicating improving living standards in, for example, Beijing and Shanghai. The mean age at menarche increased for 1940s’ birth cohorts, in relation not only to the warfare of the 1940s but also the famine of 1959–1962. The mean age at menarche decreased in a sustained way for women born during the 1950s to early 2000s. The decrease is associated with increasing educational attainment since the 1940s and also improvements in nutrition, hygiene and healthcare.

It is proposed that transgenerational modulation of gene expression might be possible, if the metabolic response of the parent to some physiological or social stress modified imprint setting. Transcription regulators could theoretically mediate this process. The nature of imprinted genes poised, as it were, between a transcriptionally active and silent state, makes them good candidates for incorporation into the evolution of transgenerational adaption systems where coordinated changes in gene expression over the generations is a selective advantage. The coordination of human fetal (head) growth with the existing size of the mother's pelvis is suggested as just such a circumstance. The reduced birth weight of Dutch babies where their grandmothers suffered acute starvation in mid pregnancy, supports the notion of transgenerational adaption to nutrition, as does the secular change (increase) in child growth over the last century. The recent indication that there may be functional polymorphism in the imprinting of the human IGF2 and IGF2R genes suggests these ideas could be explored using association studies at the population and individual level.