Kin Groups and Descent. Localized patrilineal lineages, some of which have "brother" lineages of the same or different name in other parts of Acholi, have long been the fundamental social and economic units in Acholi. Numbering between 400 and 500 by the turn of the twentieth century, these exogamous groups claim descent from a common ancestor (although means exist to incorporate many types of "outsiders" as well) and have special lineage shrines, ritual ceremonies, praise-calls, and totems.
Kinship Terminology. The Acholi have a modified Iroquois kinship-terminology system, reflecting Acholi's patrilineal and patrilocal ideology. All lineage males, for example, are called "grandfather," "father," "brother," or "son," and all (likely resident) females "sister" or "daughter," depending upon their generational relationship to the speaker. All affines, meanwhile, are known as "mother." The relationship between (real) brother and sister is often very close, especially when one acts as the lapidi (nurse-child) to the other, as are the bonds between the children of sisters. After his own father, however, a man's strongest kinship ties are typically with his mother's brother.