Observers use it to identify Tucano groups that share common descent and language, but the Tucano have no indigenous overarching sense of the tribe as a political or territorial unit, and there are no tribal leaders. Tucano marriage restrictions include sib and phratry exogamy. The kinship terminology is Iroquoian, and marriage to real or classificatory cross-cousins is the preferred, but not obligatory, pattern. The exogamic restrictions, coupled with patrilocal postmarital residence, result in a situation where the wives' primary languages are often different from their husbands'. Marriage arrangements include the payment of bride-price.
Most marriages are monogamous, the exception being a few headmen who have two wives.
Divorce is usually accomplished by the wife's returning to her paternal sib, while her children remain in their father's sib. The Tucano practice both abortion and infanticide, most frequently female infanticide. The couvade is also practiced. Naming ceremonies are held when the child is about a year old. Girls are confirmed at the time of their first menses, but there is no single puberty rite for boys.