Stature, upward social mobility and the nature of statural differences between social classes.

Stature and educational level achieved were studied in 10 groups of 19-year-old Polish men born in 1967 and examined in 1986. Each group consisted of subjects equated for (1) parental education and occupation, (2) urban-rural residence and (3) number of children in family. It was found that within each group subjects who were secondary school students or graduates were on average taller than their age-mates who by the time of examination had never moved beyond the level of elementary or basic trade school. This result is consistent with the long-debated hypothesis that in industrial societies upward social mobility tends to be selective with regard to body height. Theoretically, such social selection could be expected to inflate the magnitude of social-class differences in stature by adding to them a genetic component. However, a mechanism can be envisaged by which preferential recruitment of taller individuals to upper social strata might indeed be at work and yet produce no differential distribution of genotypes along the social scale.