Parallel and cross cousins
In discussing consanguineal kinship in anthropology, a parallel cousin (or ortho-cousin) is a cousin from a parent's same sex sibling, while a cross cousin is from a parent's opposite-sexed sibling. So a parallel cousin is the child of the father's brother (paternal uncle's child) or the mother's sister (maternal aunt's child); while a cross cousin is the child of the mother's brother (maternal uncle's child) or of the father's sister (paternal aunt's child). Where there are unilineal descent groups in a society (i.e. matrilineal and/or patrilineal), one's parallel cousins on one or both sides will belong to one's own descent group, while cross cousins will not (assuming descent group exogamy).
Role
The role of cross cousins is especially important in some cultures. For example, marriage is promoted between them and the subject (ego) in the Iroquois system. Parallel cousins are occasionally the subject of promoted marriage, such as the preferential marriage of a male ego to his father's brother's daughter, common among some pastoral peoples. Such a marriage helps keep property within a lineage. On the other hand, parallel cousin unions in some cultures would fall under an incest taboo, since parallel cousins are part of the subject's (ego's) unilineage whereas cross cousins are not.
Naming
In many societies, parallel cousins use names that western societies often associate only with direct siblings. For instance, in the Omaha system, a male parallel cousin is referred to as "brother". Likewise, a female parallel cousin is "sister". This system is also characteristic of the Crow system, the Iroquois system, the Telugu system and the Tamil system.
The Hawaiian system is different in that they apply sibling naming terminology to cross cousins as well. The Eskimo and the Sudanese have separate terminology for cross and parallel cousins.
Taboos
John Maynard Smith (1978), in The Evolution of Sex[1] notes that Richard D. Alexander suggested that paternity uncertainty may help account for the intermarriage taboo on parallel, but not on cross cousins. Fathers who are also brothers may overtly or covertly share sexual access to the wife of one or the other, raising the possibility that apparent parallel-cousins are actually half-siblings, sired by the same father. Likewise, mothers who are also sisters may overtly or covertly share sexual relations with a single man, raising the possibility that apparent parallel cousins are actually half-siblings, sired by the same father. Note that there is no possibility of any classificatory cousins sharing the same mother. Because maternal identity is never in question, they would be automatically classified as siblings. Only mistaken paternity leads to such errors.
This possibility is much less likely for cross cousins, because in the absence of full-sibling incest, it is unlikely that cross cousins can share a father by overt or covert sexual relationships. It would only be possible if Ego's mother had a brother, and Ego's father impregnated his wife, thereby allowing apparent cross cousins to be covert half-siblings, sharing the same father.
See also
- Kinship and Descent
- Family
- Genealogy
- Double first cousin
- Cultural anthropology
- Cousin marriage
- List of coupled cousins
- Mahram
Notes
- ^ Maynard Smith, J. (1978) The Evolution of Sex. Cambridge University Press. p. 142. ISBN 0-521-29302-2