Unlike in England, where kinship was predominately cognatic (derived through both males and females), in Scotland kinship was agnatic, with members of a group sharing a (sometimes fictional) common ancestor. Women retained their original surname at marriage, symbolising that they did not join their husband's kin, and marriages were intended to create friendship between kin groups, rather than a new bond of kinship.[8] Women could marry from the age of 12 (while for boys it was from 14) and, while many girls from the social elite married in their teens, most in the Lowlands only married after a period of life-cycle service, in their twenties, by which they accrued resources, status and skills that would allow them to establish a household.[9] Normally marriage followed handfasting, a period of betrothal, which in the Highlands may have effectively been a period of trial marriage, in which sexual activity may have been accepted as legitimate.[10] Highland women, based on the higher birth rate of the Highlands, might have married earlier than their Lowland counterparts.[11]