This payment was made in either livestock, money, or slaves. Marriage with any first cousin, or within one's own lineage or dia-paying group is forbidden. Although the Somali differ somewhat from the normal Islamic marriage preferences, all groups practice non-sororal polygyny including the Muslim limit of four wives. Each co-wife has her own hut, and the husband divides his time equally among all. Both the levirate and sororate are preferential in the society.
Marital residence is generally patrilocal.
Most of the significant literature on the Somali people has been written by British and Italian authors. The French interest in this region was relatively minor. Among modern writers, I. M. Lewis, a British social anthropologist, has made important contributions to the theoretical analysis of Somali institutions. Culture summary by John M. Beierle Kaplan, Irving. Area handbook for Somalia.