Aggression and polymorphisms in AR, DAT1, DRD4, and COMT genes in Datoga pastoralists of Tanzania
Marina L. Butovskaya, Vasiliy A. Vasilyev, Oleg E. Lazebny, Evgenija M. Suchodolskaya, Dmitri V. Shibalev, Alex M. Kulikov, Dmitri V. Karelin, Valentina N. Burkova, Audax Mabulla & Alexey P. Ryskov
Participants: Cultural and ecological backgrounds
The Datoga are a Nilotic people, known in Tanzania by several different names (Tatoga, Taturu, Barabaig, or Mang’ati). Their language is closely linked to the Kalenjin cluster of the southern Nilotic languages, a branch of the eastern Sudanic language family1. They are mainly concentrated in the Arusha, Dodoma, Singida, and Shinyanga regions. The population of Datoga is estimated to be between 50,000 and 100,0001,2. It is believed that between 1000 and 1800 AD, they dominated Northern Tanzania and Southern Kenya, and that in the 19th century, they were displaced from much of this area by the Maasai expansion3,4. As a result, the Datoga migrated to an area between the lakes Manyara and Eyasi, and settled in Hanang, Singida, Mbulu, and Dangabesh5. Between 1940 and Tanzanian independence in 1961, they settled in Mang’ola. However, in 1966, Mang’ola was declared an “ujamaa” village (cooperatives) and a massive influx of other tribes, particularly Iraqw agriculturalists, occurred. Farms were established bordering the springs and much of the grazing pastures of the Datoga were lost5. These processes are ongoing, so Datoga families recently began to migrate from Mang’ola to the Korogwe, Tanga, Pangani, and even the Morogoro regions in search of more valuable pastures for their cattle6.
The Datoga are seminomadic pastoralists7. They herd East African Shorthorn zebu cattle, goats, sheep, and donkeys, but since 1987, many Datoga have tried to grow maize and millet8. The Datoga practice traditional customs and are today among the poorest pastoralist populations in East Africa9.
The Datoga are polygynous, and the reproductive success of the men has been positively related to their wealth in that wealthier men have more wives and children than poor ones. Although severe violence towards other Datoga is strictly forbidden, wife-battering is quite widespread in this culture. For more details about particular Datoga populations, see Butovskaya10.
The Datoga males represented in this study live according to the traditional laws of their own culture in the rural areas of the Mang’ola region in Tanzania. Most of them did not attend school and are practically illiterate. Although violence among the Datoga is controlled by their community10, and corporal punishment or complete ostracism can be used for brutal recidivists (Butovskaya, personal communication from Datoga elders), limited physical aggression is approved as a means of “education” for children and wives. Status considerations may force Datoga men to use physical aggression against those who show then disrespect or threaten their property (grazing pastures or wells). Importantly, the Datoga men are warriors, always ready to protect their cattle from their Maasai, Sukuma, or Nyaturu neighbors, and even more importantly, violent conflicts over cattle, grazing pastures, or other belongings still occur in Northern Tanzania11-13.
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