Although the term "maternal surname" can be confused with "matriname" there is a difference in patrilineal cultures, where the maternal surname is the mother's patriname. In addition, in some cultures women inherit a surname from their mother as well as from their father.[which?]In such patrilineal cultures matrinames are able to co-exist with patrinames.
For example, where matrinames exist, they are passed from mother to child along with mitochondrial DNA (mtDNA); similarly, where patrinames exist, they are passed from father to son along with Y-chromosome DNA (Y-DNA). Thus, even within a patrilineal culture, if any group of women sharing mtDNA (from their common mother-line ancestor) were to choose a surname and then hand it down to successive generations, by definition that surname would become a matrilineal surname or matriname within a patrilineal culture. The test of whether a particular surname is a matriname is to determine whether it is being handed down from mother to daughter in a matriline.
The usual lack of matrinames to hand down in patrilineal cultures makes traditional genealogy more difficult in the mother-line case than in the normal (father-line) case. After all, father-line surnames originated partly "to identify" individuals "clearly" and were adopted partly "for administrative reasons";[c] and these patrinames help now in searching for facts and documentation from centuries ago. Thus, patrinames are stable identity-surnames, surnames which identify an individual, whether now or in the past or future; and matrinames similarly are identity-surnames for women.
Relatively recently, in its 1979 "Convention on the Elimination of Discrimination Against Women," or CEDAW, the UN officially adopted a provision, item (g) of CEDAW's Article 16, to the effect that women and men, and specifically wife and husband, shall have the same rights to choose a "family name", as well as a "profession" and an "occupation". These three rights are only a small part of the document's long list of rights related to gender equality meant to ensure women have equal opportunities to men. However, according to the article, The United States has not yet ratified this UN Convention, or the multilateral treaty.
Thus, in non-discriminating States, women may eventually gain the same right to their own matriname as men have traditionally had (within father-line cultures) to their own patriname. And similarly, within mother-line or matrilineal cultures, men may gain the right to their own patriname. In other words, the handing down of both matrinames and patrinames would co-exist within each culture to avoid discriminating against either women or men. (Note that some cultures have no surnames – but if a culture has surnames then in this regard a non-discriminating culture would be a both-lines [mother-line and father-line] or ambilineal culture.)
The actual use of a matriname would involve, first, invention or choice of a name by a group of women who share mtDNA (from their common matriline ancestor) and then using it in their daughters' birth records (or birth certificates).
This use of the mother's matriname would be parallel to and symmetric with the normal use of the father's patriname in each new son's birth record. Note well; this is the above-mentioned "handing down of both" the matriname and the patriname.
It should be mentioned that the patriname is normally a single surname, like Smith or Jones, normally not a double surname like Smith-Jones or Smith Jones.[d] (The matriname and patriname examples used later in this article are all single surnames, for simplicity and clarity.) And, just as men normally do not change their patriname,[d] so also women would normally not change their matriname. Thus both identity-surnames should be equally stable over the generations.
Note that one's birth surname is one's legal surname, unless one changes the latter – such as in some purely patrilineal cultures where women traditionally change to their husband's patriname at marriage, as described in Married and maiden names and in Name change.
Here is a specific example to illustrate and summarize these concepts: the father and sons in a nuclear family have the very-familiar patriname Smith while the mother and daughters have the matriname Momline as their own (and thus equally stable) identity-surname.
This section has focused on the single surname, for simplicity and clarity, before covering the resulting double surname in the next section.
The four double surname possibilities which combine a matriname with a patriname (in either order, and with or without a hyphen) – and which thus provide the above-mentioned gender symmetry – are as follows: matriname patriname, matriname-patriname, patriname matriname, and patriname-matriname.
The patrilineal surname or patriname, received from the mother in such patrilineal cultures, does not qualify as a matriname, as already discussed in the previous section.
Three of the four possibilities above are used together in the example below. Such double surnames were proposed in the book The Seven Daughters of Eve; and an actual case from England, with the family matriname Phythian, is thoroughly demonstrated and discussed in a "feature" article which is available online.
As a specific example of these double surnames, let the matrinames be Mamaname and Momline and let the patrinames be Smith and Jones. The mother (with birth double surname Momline-Jones, for example) and the father (with double birth surname Mamaname Smith as another example) both choose to keep their legal or birth double surnames unchanged throughout their lives, and agree somehow to give all of their daughters and sons the double birth surname, Smith Momline : The mother hands down the matriname part of her birth surname while, symmetrically, the father hands down the patriname part of his. All sons have the Y-DNA as well as the patriname Smith of their patriline, while all daughters have both the mtDNA and the matriname Momline of their matriline. (Note, most cultures do give all children in a family the same surname or family name, as in this example.)
Each person has only one identity-surname, which in this example is either Momline or Smith. Their identity-surname is stable throughout life, as discussed in the previous section,[d] and is always half of whatever double surname(s) they legally acquire throughout life, such as at birth and at marriage(s).
The family in this specific example could choose to handle its three coexisting legal surnames Momline-Jones, Mamaname Smith, and Smith Momline by all using just one family "usage name" in daily social life. (Possible samples of this family's usage name might be: any one of its three coexisting double surnames; or one of its identity-surnames Momline or Smith; or Momith or any other invented name. Single surname families can use such usage names too. There is related discussion in this footnote.[e]) This family's three legal surnames, however, must be used in their respective members' own legal documents, and may also be used otherwise such as in the respective members' own professional/vocational lives.
Rather than keeping their own birth or legal surnames, the parents in this example might prefer, at marriage, to change their legal surnames to Smith Momline, the same as their children-to-be, so that their nuclear family would all share this one legal surname.
Of course one's own identity-surname (here, the matriname Momline or the patriname Smith) is always available as one's own usage name, such as in one's vocational life.
This double surname example should be compared with its single surname version at the end of the previous section.
An overall comparison: The gender-symmetric single surnames presented in the previous section have the advantage of being simpler and briefer, but if actually used alone, would give different surnames for two genders in a nuclear family. In contrast, all of the children in a nuclear family have the same double surname. Also, these double surnames do record (on legal documents) both matriname and patriname, with both identity-surnames later aiding each gender in genealogy work and other historical-record searching.