Ethnic variation of twinning rates in Malawi

Malawi is a country in South-East Africa with a population of approximately 10 million, over 95% of whom are negro of Bantu origin. The country is divided into 24 administrative districts, each of which provides details of births which are compiled centrally at the Ministry of Health. Using data reported annually by health facilities from 1987-1990, most districts had twinning rates in the range 16 to 24 per 1000 maternities, figures consistent with those of other negro populations in Africa. Two adjoining districts (Rumphi and Mzimba) had rates which were considerably higher, almost 30 per 1000. Although ethnic origin is not recorded in the latest Malawi census, language spoken in the home, which was last recorded in 1966, can be used as a proxy. Rumphi and Mzimba are the only districts with an overwhelming majority of Tumbuka speaking population. These people, who are of both Tumbuka and Ngoni ethnic origin, therefore have an unusually high twinning rate (29.57 per 1000 maternities). The rate for the main ethnic group in Malawi, the Chewa people, was 21.21 per 1000. The district of Thyolo, with a mixed ethnic population, had by far the lowest rate (13.75 per 1000).