The analysis covered girls, aged 9-18, from farmer, farmer-worker and nonfarmer rural families inhabiting 4 regions of Poland. Additionally, parents' education, number of children per family and the wealth of the family were recorded. The aim of the study was to assess the impact of social stratification of the rural population, the economic crisis (1978)(1979)(1980)(1981)(1982)(1983)(1984)(1985)(1986)(1987)(1988)(1989) and political and economic transition (1989) on the girls' biological

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... tion. Age at menarche and body height were used as biological measures of living conditions. In the period 1967-1977 a marked acceleration in maturation and a significant increase in average body height were noted. The study repeated in 1987 demonstrated negative effects of the economic crisis (1977)(1978)(1979)(1980)(1981)(1982)(1983)(1984)(1985)(1986)(1987)(1988)(1989). Research findings from 2001, after the political system transformation, provide evidence 'compensating for losses' recorded in girls' biological condition during the crisis. The diversity of biogeographic and socioeconomic conditions of rural inhabitants in the studied regions is reflected in a marked diversification in age of menarche and body height.