Religion and intensity of inbreeding in Tamil Nadu, South India

Abstract

A representative random sample of 11,628 rural couples and 8,998 urban couples from North Arcot District of Tamil Nadu in South India are under follow up since 1969 in a study of inbreeding eflFects. This paper describes the level of inbreeding and its relationship to religion of the couples. Wright's F for autosomal genes in the rural and urban areas were 0.0371 and 0.0205, respectively. The F for sex‐linked genes was significantly higher than that for autosomal and was 0.0411 in the rural areas and 0.0228 in the urban. Hindus had the highest inbreeding coefficients as compared to Muslims or Christians for both autosomal and sex‐linked genes, but there were significant variations among the different castes. The level of inbreeding among Muslims and Christians was similar and fairly high. Significant rural‐urban differentials persist in all religions. There is no appreciable change in the level of inbreeding over the past few decades in any religion, although minor declines are observed in certain castes in the urban areas.