The method of determining the family reference person is the same as that of the reference person of the household (see Reference person of the household - complementary processing (population census)), applied to each family, primary and secondary.
As of the 2016 census, the determination of the family reference person is changed. In vintages prior to 2016, this determination took into account the gender criterion. Thus, previously, if the family is composed of a couple of the opposite sex, the reference person in the family is then the man of the couple. If the family includes a same-sex couple, the reference person is the oldest asset, or failing that, the oldest. In the case of a single-parent family, this is the parent (called a "single-parent family adult").
A household may contain none, one or more families. Each family contains only one reference person and a household contains only one reference person who is also the reference person of the main family of the household in the case where this household contains at least one family.