The Coming of the Maori
All members of a Maori tribe are related to each other by blood descent, and the record of a common tie is preserved in the family genealogies which form oral registers of the births and marriages extending back to the common ancestors of the tribe. The kinship terms in use are capable of expressing the relationship between any two members of the tribe and any doubt is settled by a recital of the lineages of the persons concerned.page 339
In the biological family, the kinship terms cover the two preceding generations of parents and grandparents, the generation of the person concerned, and the two succeeding generations of children and grandchildren. In a genealogical count, if we place the generation of the individual concerned as zero (0), his parents are one shorter (–1) and his grandparents are two shorter (–2) whereas his children are one longer (+1) and his grandchildren two longer (+2). In the following list, the kinship terms are placed in the five generation strata described above, for it forms the key by which the relationship between any two members of a tribe may be established.