Secular change in height in Austria: an effect of population stratification?

The records of height on some 700,000 18-year-old Austrian males, called for examination as to their fitness for conscription, were analysed. The data covered 14 conscription years (1980-93), representing males born in the years 1962-75. The sample covered over 90% of the total male population of those cohorts in Austria. The data were analysed by birth year to show the secular trend in 18-year-old stature and its rate, which overall amounted to 0.53 cm/decade. Analysis by urban-rural residence showed that both participated in the trend, but that the urban-rural differences were appreciably less than the differences between the types of school the young men had attended. The rate of increase over the 14 years was less within each of the eight subgroups (urban-rural, four school categories). It is argued that the secular trend in height that has occurred is largely attributable to the change in social stratification, as evidenced by the changed proportion of subjects who attended schools of different types.