The maturation rate of girls living in rich and poor rural regions of Poland before and after the transformation of 1989.

The aim of this study was to find out whether the political and economic system transformation in Poland in 1989 had an influence on the rate of maturation of girls from various categories of the rural population in two regions, differing in wealth. The stratification of the villagers was based on the source of the family income (farmers, farmer-workers and non-farmers), on parents' education, and on the number of children per family. The age at menarche (AM) was used as biological indicator of living conditions. Rural girls aged 9.5-18.5 years were studied in 1987 in Leszno (L), a rich region (n = 2049), and in 1989 in Suwa?ki (S), a poor region (n = 2077). The study was repeated in 2001 in the same villages, the numbers of subjects amounting to 2440 and 2122, respectively. In the 1980s, AM in regions L and S amounted to 13.18 and 13.88 years, respectively, and was strongly related to social stratification. The earliest AM was found in daughters of non-farmers and the latest in the girls from farmers' families. In 2001, the acceleration in AM amounted to 0.14 years in the rich region and to 0.46 years in the poor region. The percentage of families owning a car, freezer, colour TV and automatic washing machine markedly increased and the education of parents improved. Such results are indicative of an improvement in the living standard of the groups investigated, but the villagers regard themselves as the losers as a result of the system transformation in Poland. Since the Polish population is considered as ethnically homogenous, the great differences in AM within the rural population, as well as the differences between the inhabitants of villages and large cities should be regarded as biological effects of social inequalities. Such differences indicate that Polish rural girls are far below the genetic potential for menarcheal age.