A biosocial approach to living conditions: inter-generational changes of stature dimorphism in 20th-century Spain

Background: Applying sexual stature dimorphism (SSD) to history and the social sciences faces the difficulty of disentangling nature from nurture in addition to the limitations of sources (e. g. small, fragmented or heterogeneous samples). Aim: To investigate the relationship between inter-generational changes and social differences in SSD and the evolution of living conditions in 20th-century Spain. Subjects and methods: Self-reported height and socio-demographic information from individuals born 1910-1979 (n = 99 023) were drawn from health interview surveys. Weighed least squares regression was used to construct continuous time-cohort series of SSD for the entire population and for specific socioeconomic groups represented by levels of educational attainment. Results: SSD remained below modern values among cohorts that were exposed to structural deprivation at pre-adult ages. Socioeconomic status mediated the correction of these deviations among subsequent cohorts. Lower classes (less educated segments of the population) systematically deviated to a greater extent from normal modern SSD values and they reached these values later in time. Conclusions: In Spain, variations in SSD have been found that are associated with both socioeconomic changes at a nationwide level and SES differentials at the individual level, thus continuous series of this indicator offer new opportunities in the study of living conditions of current and past generations.