"We have three main forms of the family, corresponding in general to the three main stages of human development. For savagery group marriage, for barbarism the pairing family, for civilization, monogamy supplemented by adultery and prostitution."
THE PAIRING FAMILY
"A certain pairing for a longer or shorter term took place even during the group marriage or still earlier. A man had his principal wife among other women, and he was to her the principal husband among others… Such a habitual pairing would gain ground the more the gens developed and the more numerous the classes of "brothers" and "sisters" became who were not permitted to marry one another…
"By this increasing complication of marriage restrictions, group marriage became more and more impossible; it was displaced by the pairing family.
